From c45d0b010f7ac62038318b05797af2cb9873f849 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Wed, 16 Nov 2022 16:49:28 +0000
Subject: [PATCH 01/59] Refactor `ConstrainedStringGenerator` to extract length
 checking

---
 .../generators/ConstrainedStringGenerator.kt  | 66 ++++++++++++-------
 1 file changed, 41 insertions(+), 25 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index a63801cce4..44695daa17 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -5,6 +5,7 @@
 
 package software.amazon.smithy.rust.codegen.server.smithy.generators
 
+import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.model.shapes.StringShape
 import software.amazon.smithy.model.traits.LengthTrait
 import software.amazon.smithy.rust.codegen.core.rustlang.Attribute
@@ -50,6 +51,26 @@ class ConstrainedStringGenerator(
             }
         }
 
+    fun renderLengthValidation(lengthTrait: LengthTrait, constraintViolation: Symbol) {
+        val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
+            "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
+        } else if (lengthTrait.min.isPresent) {
+            "${lengthTrait.min.get()} <= length"
+        } else {
+            "length <= ${lengthTrait.max.get()}"
+        }
+        writer.rust("""
+            fn check_length(string: &str) -> Result<(), $constraintViolation> {
+                let length = string.chars().count();
+
+                if $condition {
+                    Ok(())
+                } else {
+                    Err($constraintViolation::Length(length))
+                }
+            }
+        """.trimIndent())
+    }
     fun render() {
         val lengthTrait = shape.expectTrait<LengthTrait>()
 
@@ -58,13 +79,6 @@ class ConstrainedStringGenerator(
         val inner = RustType.String.render()
         val constraintViolation = constraintViolationSymbolProvider.toSymbol(shape)
 
-        val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
-            "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
-        } else if (lengthTrait.min.isPresent) {
-            "${lengthTrait.min.get()} <= length"
-        } else {
-            "length <= ${lengthTrait.max.get()}"
-        }
 
         val constrainedTypeVisibility = if (publicConstrainedTypes) {
             Visibility.PUBLIC
@@ -85,55 +99,57 @@ class ConstrainedStringGenerator(
         if (constrainedTypeVisibility == Visibility.PUBCRATE) {
             Attribute.AllowUnused.render(writer)
         }
-        writer.rustTemplate(
-            """
-            impl $name {
+        writer.rustBlockTemplate("impl $name") {
+            renderLengthValidation(lengthTrait, constraintViolation)
+
+            rust("""
                 /// Extracts a string slice containing the entire underlying `String`.
                 pub fn as_str(&self) -> &str {
                     &self.0
                 }
-                
+
                 /// ${rustDocsInnerMethod(inner)}
                 pub fn inner(&self) -> &$inner {
                     &self.0
                 }
-                
+
                 /// ${rustDocsIntoInnerMethod(inner)}
                 pub fn into_inner(self) -> $inner {
                     self.0
                 }
-            }
-            
+            """.trimIndent())
+        }
+
+
+        writer.rustTemplate(
+            """
             impl #{ConstrainedTrait} for $name  {
                 type Unconstrained = $inner;
             }
-            
+
             impl #{From}<$inner> for #{MaybeConstrained} {
                 fn from(value: $inner) -> Self {
                     Self::Unconstrained(value)
                 }
             }
-            
+
             impl #{Display} for $name {
                 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
                    ${shape.redactIfNecessary(model, "self.0")}.fmt(f)
                 }
             }
-            
+
             impl #{TryFrom}<$inner> for $name {
                 type Error = #{ConstraintViolation};
-                
+
                 /// ${rustDocsTryFromMethod(name, inner)}
                 fn try_from(value: $inner) -> Result<Self, Self::Error> {
-                    let length = value.chars().count();
-                    if $condition {
-                        Ok(Self(value))
-                    } else {
-                        Err(#{ConstraintViolation}::Length(length))
-                    }
+                    Self::check_length(&value)?;
+
+                    Ok(Self(value))
                 }
             }
-            
+
             impl #{From}<$name> for $inner {
                 fn from(value: $name) -> Self {
                     value.into_inner()

From bc29310cd325cc4c5f45313d12ec6f0afc92b9fb Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 10:13:11 +0000
Subject: [PATCH 02/59] Extract `TryFrom` rendering into its own function

---
 .../generators/ConstrainedStringGenerator.kt  | 48 +++++++++++++------
 1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 44695daa17..04d4c0b990 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -23,6 +23,7 @@ import software.amazon.smithy.rust.codegen.core.rustlang.rustTemplate
 import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
 import software.amazon.smithy.rust.codegen.core.smithy.makeMaybeConstrained
 import software.amazon.smithy.rust.codegen.core.util.expectTrait
+import software.amazon.smithy.rust.codegen.core.util.getTrait
 import software.amazon.smithy.rust.codegen.core.util.redactIfNecessary
 import software.amazon.smithy.rust.codegen.server.smithy.PubCrateConstraintViolationSymbolProvider
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
@@ -51,7 +52,7 @@ class ConstrainedStringGenerator(
             }
         }
 
-    fun renderLengthValidation(lengthTrait: LengthTrait, constraintViolation: Symbol) {
+    private fun renderLengthValidation(lengthTrait: LengthTrait, constraintViolation: Symbol) {
         val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
             "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
         } else if (lengthTrait.min.isPresent) {
@@ -71,9 +72,38 @@ class ConstrainedStringGenerator(
             }
         """.trimIndent())
     }
+
+    private fun renderTryFrom(inner: String, name: String, shape: StringShape, constraintViolation: Symbol) {
+        val lengthTrait = shape.getTrait<LengthTrait>()
+
+        var lengthCheck = ""
+        if (lengthTrait != null) {
+            lengthCheck = "Self::check_length(&value);?"
+
+            writer.rustBlock("impl $name") {
+                renderLengthValidation(lengthTrait, constraintViolation)
+            }
+        }
+
+        writer.rustTemplate(
+            """
+            impl #{TryFrom}<$inner> for $name {
+                type Error = #{ConstraintViolation};
+
+                /// ${rustDocsTryFromMethod(name, inner)}
+                fn try_from(value: $inner) -> Result<Self, Self::Error> {
+                    $lengthCheck
+                    Ok(Self(value))
+                }
+            }
+            """.trimIndent(),
+            "ConstraintViolation" to constraintViolation,
+            "TryFrom" to RuntimeType.TryFrom,
+        )
+    }
+
     fun render() {
         val lengthTrait = shape.expectTrait<LengthTrait>()
-
         val symbol = constrainedShapeSymbolProvider.toSymbol(shape)
         val name = symbol.name
         val inner = RustType.String.render()
@@ -100,8 +130,6 @@ class ConstrainedStringGenerator(
             Attribute.AllowUnused.render(writer)
         }
         writer.rustBlockTemplate("impl $name") {
-            renderLengthValidation(lengthTrait, constraintViolation)
-
             rust("""
                 /// Extracts a string slice containing the entire underlying `String`.
                 pub fn as_str(&self) -> &str {
@@ -120,6 +148,7 @@ class ConstrainedStringGenerator(
             """.trimIndent())
         }
 
+        renderTryFrom(inner, name, shape, constraintViolation)
 
         writer.rustTemplate(
             """
@@ -139,16 +168,6 @@ class ConstrainedStringGenerator(
                 }
             }
 
-            impl #{TryFrom}<$inner> for $name {
-                type Error = #{ConstraintViolation};
-
-                /// ${rustDocsTryFromMethod(name, inner)}
-                fn try_from(value: $inner) -> Result<Self, Self::Error> {
-                    Self::check_length(&value)?;
-
-                    Ok(Self(value))
-                }
-            }
 
             impl #{From}<$name> for $inner {
                 fn from(value: $name) -> Self {
@@ -161,7 +180,6 @@ class ConstrainedStringGenerator(
             "MaybeConstrained" to symbol.makeMaybeConstrained(),
             "Display" to RuntimeType.Display,
             "From" to RuntimeType.From,
-            "TryFrom" to RuntimeType.TryFrom,
         )
 
         val constraintViolationModuleName = constraintViolation.namespace.split(constraintViolation.namespaceDelimiter).last()

From 44495b9f54744f0c21ee9b2223964f88e60cb8fc Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 10:19:20 +0000
Subject: [PATCH 03/59] Extract `ConstraintViolation` definition to separate
 function

---
 .../generators/ConstrainedStringGenerator.kt  | 56 ++++++++++---------
 1 file changed, 31 insertions(+), 25 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 04d4c0b990..86ae3f5617 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -184,31 +184,37 @@ class ConstrainedStringGenerator(
 
         val constraintViolationModuleName = constraintViolation.namespace.split(constraintViolation.namespaceDelimiter).last()
         writer.withModule(RustModule(constraintViolationModuleName, RustMetadata(visibility = constrainedTypeVisibility))) {
-            rust(
-                """
-                ##[derive(Debug, PartialEq)]
-                pub enum ${constraintViolation.name} {
-                    Length(usize),
-                }
-                """,
-            )
-
-            if (shape.isReachableFromOperationInput()) {
-                rustBlock("impl ${constraintViolation.name}") {
-                    rustBlockTemplate(
-                        "pub(crate) fn as_validation_exception_field(self, path: #{String}) -> crate::model::ValidationExceptionField",
-                        "String" to RuntimeType.String,
-                    ) {
-                        rustBlock("match self") {
-                            rust(
-                                """
-                                Self::Length(length) => crate::model::ValidationExceptionField {
-                                    message: format!("${lengthTrait.validationErrorMessage()}", length, &path),
-                                    path,
-                                },
-                                """,
-                            )
-                        }
+            renderConstraintViolationEnum(this, shape, constraintViolation)
+        }
+    }
+
+    private fun renderConstraintViolationEnum(writer: RustWriter, shape: StringShape, constraintViolation: Symbol) {
+        val lengthTrait = shape.expectTrait<LengthTrait>()
+
+        writer.rust(
+            """
+            ##[derive(Debug, PartialEq)]
+            pub enum ${constraintViolation.name} {
+                Length(usize),
+            }
+            """,
+        )
+
+        if (shape.isReachableFromOperationInput()) {
+            writer.rustBlock("impl ${constraintViolation.name}") {
+                rustBlockTemplate(
+                    "pub(crate) fn as_validation_exception_field(self, path: #{String}) -> crate::model::ValidationExceptionField",
+                    "String" to RuntimeType.String,
+                ) {
+                    rustBlock("match self") {
+                        rust(
+                            """
+                            Self::Length(length) => crate::model::ValidationExceptionField {
+                                message: format!("${lengthTrait.validationErrorMessage()}", length, &path),
+                                path,
+                            },
+                            """,
+                        )
                     }
                 }
             }

From e140694e8e5489f24d194bc8e4c788a19bc7ebc4 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 11:17:51 +0000
Subject: [PATCH 04/59] Add pattern check mock for `@pattern` trait

---
 .../generators/ConstrainedStringGenerator.kt  | 56 ++++++++++++++-----
 1 file changed, 42 insertions(+), 14 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 86ae3f5617..13355eebd6 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -8,6 +8,7 @@ package software.amazon.smithy.rust.codegen.server.smithy.generators
 import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.model.shapes.StringShape
 import software.amazon.smithy.model.traits.LengthTrait
+import software.amazon.smithy.model.traits.PatternTrait
 import software.amazon.smithy.rust.codegen.core.rustlang.Attribute
 import software.amazon.smithy.rust.codegen.core.rustlang.RustMetadata
 import software.amazon.smithy.rust.codegen.core.rustlang.RustModule
@@ -22,7 +23,6 @@ import software.amazon.smithy.rust.codegen.core.rustlang.rustBlockTemplate
 import software.amazon.smithy.rust.codegen.core.rustlang.rustTemplate
 import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
 import software.amazon.smithy.rust.codegen.core.smithy.makeMaybeConstrained
-import software.amazon.smithy.rust.codegen.core.util.expectTrait
 import software.amazon.smithy.rust.codegen.core.util.getTrait
 import software.amazon.smithy.rust.codegen.core.util.redactIfNecessary
 import software.amazon.smithy.rust.codegen.server.smithy.PubCrateConstraintViolationSymbolProvider
@@ -52,7 +52,7 @@ class ConstrainedStringGenerator(
             }
         }
 
-    private fun renderLengthValidation(lengthTrait: LengthTrait, constraintViolation: Symbol) {
+    private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait, constraintViolation: Symbol) {
         val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
             "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
         } else if (lengthTrait.min.isPresent) {
@@ -60,7 +60,8 @@ class ConstrainedStringGenerator(
         } else {
             "length <= ${lengthTrait.max.get()}"
         }
-        writer.rust("""
+        writer.rust(
+            """
             fn check_length(string: &str) -> Result<(), $constraintViolation> {
                 let length = string.chars().count();
 
@@ -70,21 +71,41 @@ class ConstrainedStringGenerator(
                     Err($constraintViolation::Length(length))
                 }
             }
-        """.trimIndent())
+            """.trimIndent(),
+        )
     }
 
+    private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
+        val pattern = patternTrait.pattern.toString()
+
+        writer.rust(
+            """
+            fn check_pattern(_string: &str) -> Result<(), $constraintViolation> {
+                return Err($constraintViolation::Pattern("$pattern".to_owned()));
+            }
+            """.trimIndent(),
+        )
+    }
     private fun renderTryFrom(inner: String, name: String, shape: StringShape, constraintViolation: Symbol) {
         val lengthTrait = shape.getTrait<LengthTrait>()
+        val patternTrait = shape.getTrait<PatternTrait>()
 
         var lengthCheck = ""
         if (lengthTrait != null) {
-            lengthCheck = "Self::check_length(&value);?"
+            lengthCheck = "Self::check_length(&value)?;"
 
             writer.rustBlock("impl $name") {
-                renderLengthValidation(lengthTrait, constraintViolation)
+                renderLengthValidation(writer, lengthTrait, constraintViolation)
             }
         }
 
+        var patternCheck = ""
+        if (patternTrait != null) {
+            patternCheck = "Self::check_pattern(&value)?;"
+            writer.rustBlock("impl $name") {
+                renderPatternValidation(writer, patternTrait, constraintViolation)
+            }
+        }
         writer.rustTemplate(
             """
             impl #{TryFrom}<$inner> for $name {
@@ -93,6 +114,7 @@ class ConstrainedStringGenerator(
                 /// ${rustDocsTryFromMethod(name, inner)}
                 fn try_from(value: $inner) -> Result<Self, Self::Error> {
                     $lengthCheck
+                    $patternCheck
                     Ok(Self(value))
                 }
             }
@@ -103,13 +125,11 @@ class ConstrainedStringGenerator(
     }
 
     fun render() {
-        val lengthTrait = shape.expectTrait<LengthTrait>()
         val symbol = constrainedShapeSymbolProvider.toSymbol(shape)
         val name = symbol.name
         val inner = RustType.String.render()
         val constraintViolation = constraintViolationSymbolProvider.toSymbol(shape)
 
-
         val constrainedTypeVisibility = if (publicConstrainedTypes) {
             Visibility.PUBLIC
         } else {
@@ -130,7 +150,8 @@ class ConstrainedStringGenerator(
             Attribute.AllowUnused.render(writer)
         }
         writer.rustBlockTemplate("impl $name") {
-            rust("""
+            rust(
+                """
                 /// Extracts a string slice containing the entire underlying `String`.
                 pub fn as_str(&self) -> &str {
                     &self.0
@@ -145,7 +166,8 @@ class ConstrainedStringGenerator(
                 pub fn into_inner(self) -> $inner {
                     self.0
                 }
-            """.trimIndent())
+                """.trimIndent(),
+            )
         }
 
         renderTryFrom(inner, name, shape, constraintViolation)
@@ -189,13 +211,15 @@ class ConstrainedStringGenerator(
     }
 
     private fun renderConstraintViolationEnum(writer: RustWriter, shape: StringShape, constraintViolation: Symbol) {
-        val lengthTrait = shape.expectTrait<LengthTrait>()
+        val lengthTrait = shape.getTrait<LengthTrait>()
+        val patternTrait = shape.getTrait<PatternTrait>()
 
         writer.rust(
             """
             ##[derive(Debug, PartialEq)]
             pub enum ${constraintViolation.name} {
-                Length(usize),
+                ${if (lengthTrait != null) "Length(usize)," else ""}
+                ${if (patternTrait != null) "Pattern(String)," else ""}
             }
             """,
         )
@@ -209,10 +233,14 @@ class ConstrainedStringGenerator(
                     rustBlock("match self") {
                         rust(
                             """
-                            Self::Length(length) => crate::model::ValidationExceptionField {
+                            ${if (lengthTrait != null) """Self::Length(length) => crate::model::ValidationExceptionField {
                                 message: format!("${lengthTrait.validationErrorMessage()}", length, &path),
                                 path,
-                            },
+                            }""" else ""},
+                            ${ if (patternTrait != null) """Self::Pattern(pattern) => crate::model::ValidationExceptionField {
+                                message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
+                                path
+                            }""" else ""}
                             """,
                         )
                     }

From ae21ce7099e49a2f0e55250d0f239d9fd9de6fe3 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 11:54:23 +0000
Subject: [PATCH 05/59] Add `regex` to list of server dependencies

---
 .../smithy/rust/codegen/server/smithy/ServerCargoDependency.kt   | 1 +
 1 file changed, 1 insertion(+)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCargoDependency.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCargoDependency.kt
index 6058519abf..ef2e930dfd 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCargoDependency.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCargoDependency.kt
@@ -25,6 +25,7 @@ object ServerCargoDependency {
     val PinProjectLite: CargoDependency = CargoDependency("pin-project-lite", CratesIo("0.2"))
     val Tower: CargoDependency = CargoDependency("tower", CratesIo("0.4"))
     val TokioDev: CargoDependency = CargoDependency("tokio", CratesIo("1.8.4"), scope = DependencyScope.Dev)
+    val Regex: CargoDependency = CargoDependency("regex", CratesIo("1.7.0"))
 
     fun SmithyHttpServer(runtimeConfig: RuntimeConfig) = runtimeConfig.runtimeCrate("http-server")
 }

From 4c6384dad180b990425d2effb5af889198dfae29 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 11:55:23 +0000
Subject: [PATCH 06/59] Use real regex check in `check_pattern`

---
 .../generators/ConstrainedStringGenerator.kt      | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 13355eebd6..3edc811a42 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -15,6 +15,7 @@ import software.amazon.smithy.rust.codegen.core.rustlang.RustModule
 import software.amazon.smithy.rust.codegen.core.rustlang.RustType
 import software.amazon.smithy.rust.codegen.core.rustlang.RustWriter
 import software.amazon.smithy.rust.codegen.core.rustlang.Visibility
+import software.amazon.smithy.rust.codegen.core.rustlang.asType
 import software.amazon.smithy.rust.codegen.core.rustlang.documentShape
 import software.amazon.smithy.rust.codegen.core.rustlang.render
 import software.amazon.smithy.rust.codegen.core.rustlang.rust
@@ -26,6 +27,7 @@ import software.amazon.smithy.rust.codegen.core.smithy.makeMaybeConstrained
 import software.amazon.smithy.rust.codegen.core.util.getTrait
 import software.amazon.smithy.rust.codegen.core.util.redactIfNecessary
 import software.amazon.smithy.rust.codegen.server.smithy.PubCrateConstraintViolationSymbolProvider
+import software.amazon.smithy.rust.codegen.server.smithy.ServerCargoDependency
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
 import software.amazon.smithy.rust.codegen.server.smithy.traits.isReachableFromOperationInput
 import software.amazon.smithy.rust.codegen.server.smithy.validationErrorMessage
@@ -78,12 +80,19 @@ class ConstrainedStringGenerator(
     private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
         val pattern = patternTrait.pattern.toString()
 
-        writer.rust(
+        writer.rustTemplate(
             """
-            fn check_pattern(_string: &str) -> Result<(), $constraintViolation> {
-                return Err($constraintViolation::Pattern("$pattern".to_owned()));
+            fn check_pattern(string: &str) -> Result<(), $constraintViolation> {
+                let regex = #{Regex}::Regex::new("$pattern").unwrap();
+
+                if regex.is_match(string) {
+                    Ok(())
+                } else {
+                    Err($constraintViolation::Pattern("$pattern".to_owned()))
+                }
             }
             """.trimIndent(),
+            "Regex" to ServerCargoDependency.Regex.asType(),
         )
     }
     private fun renderTryFrom(inner: String, name: String, shape: StringShape, constraintViolation: Symbol) {

From c3e96598ef0ba425aefaec4c8ca31b12234f98f5 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 12:14:06 +0000
Subject: [PATCH 07/59] Add `@pattern` to traits that make `string` shapes
 directly constrained

---
 .../amazon/smithy/rust/codegen/server/smithy/Constraints.kt    | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt
index 82102be18a..c8f8684f18 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt
@@ -66,7 +66,8 @@ fun Shape.isDirectlyConstrained(symbolProvider: SymbolProvider): Boolean = when
         this.members().map { symbolProvider.toSymbol(it) }.any { !it.isOptional() }
     }
     is MapShape -> this.hasTrait<LengthTrait>()
-    is StringShape -> this.hasTrait<EnumTrait>() || this.hasTrait<LengthTrait>()
+    is StringShape ->
+        this.hasTrait<EnumTrait>() || this.hasTrait<LengthTrait>() || this.hasTrait<PatternTrait>()
     else -> false
 }
 

From b950c19b257f1870c22f9d8b4173483ebb2cf2b2 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 12:15:35 +0000
Subject: [PATCH 08/59] Remove unsupported validation for `@pattern` on strings

---
 .../smithy/ValidateUnsupportedConstraints.kt  | 41 ++++++-------------
 1 file changed, 12 insertions(+), 29 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraints.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraints.kt
index d487689b20..cdc745a8e6 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraints.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraints.kt
@@ -16,7 +16,6 @@ import software.amazon.smithy.model.shapes.ServiceShape
 import software.amazon.smithy.model.shapes.SetShape
 import software.amazon.smithy.model.shapes.Shape
 import software.amazon.smithy.model.shapes.ShapeId
-import software.amazon.smithy.model.shapes.StringShape
 import software.amazon.smithy.model.shapes.UnionShape
 import software.amazon.smithy.model.traits.EnumTrait
 import software.amazon.smithy.model.traits.LengthTrait
@@ -86,10 +85,6 @@ private sealed class UnsupportedConstraintMessageKind {
                 level,
                 buildMessageShapeHasUnsupportedConstraintTrait(shape, lengthTrait, constraintTraitsUberIssue),
             )
-            is UnsupportedPatternTraitOnStringShape -> LogMessage(
-                level,
-                buildMessageShapeHasUnsupportedConstraintTrait(shape, patternTrait, constraintTraitsUberIssue),
-            )
             is UnsupportedRangeTraitOnShape -> LogMessage(
                 level,
                 buildMessageShapeHasUnsupportedConstraintTrait(shape, rangeTrait, constraintTraitsUberIssue),
@@ -102,7 +97,6 @@ private data class UnsupportedConstraintOnMemberShape(val shape: MemberShape, va
 private data class UnsupportedConstraintOnShapeReachableViaAnEventStream(val shape: Shape, val constraintTrait: Trait) : UnsupportedConstraintMessageKind()
 private data class UnsupportedLengthTraitOnStreamingBlobShape(val shape: BlobShape, val lengthTrait: LengthTrait, val streamingTrait: StreamingTrait) : UnsupportedConstraintMessageKind()
 private data class UnsupportedLengthTraitOnCollectionOrOnBlobShape(val shape: Shape, val lengthTrait: LengthTrait) : UnsupportedConstraintMessageKind()
-private data class UnsupportedPatternTraitOnStringShape(val shape: Shape, val patternTrait: PatternTrait) : UnsupportedConstraintMessageKind()
 private data class UnsupportedRangeTraitOnShape(val shape: Shape, val rangeTrait: RangeTrait) : UnsupportedConstraintMessageKind()
 
 data class LogMessage(val level: Level, val message: String)
@@ -141,20 +135,20 @@ fun validateOperationsWithConstrainedInputHaveValidationExceptionAttached(model:
             LogMessage(
                 Level.SEVERE,
                 """
-                Operation ${it.shape.id} takes in input that is constrained 
-                (https://awslabs.github.io/smithy/2.0/spec/constraint-traits.html), and as such can fail with a validation 
+                Operation ${it.shape.id} takes in input that is constrained
+                (https://awslabs.github.io/smithy/2.0/spec/constraint-traits.html), and as such can fail with a validation
                 exception. You must model this behavior in the operation shape in your model file.
                 """.trimIndent().replace("\n", "") +
                     """
-                        
-                ```smithy
-                use smithy.framework#ValidationException
-                
-                operation ${it.shape.id.name} {
-                    ...
-                    errors: [..., ValidationException] // <-- Add this.
-                }
-                ```
+
+                    ```smithy
+                    use smithy.framework#ValidationException
+
+                    operation ${it.shape.id.name} {
+                        ...
+                        errors: [..., ValidationException] // <-- Add this.
+                    }
+                    ```
                     """.trimIndent(),
             )
         }
@@ -209,17 +203,7 @@ fun validateUnsupportedConstraints(model: Model, service: ServiceShape, codegenC
         .map { UnsupportedLengthTraitOnCollectionOrOnBlobShape(it, it.expectTrait()) }
         .toSet()
 
-    // 5. Pattern trait on string shapes is used. It has not been implemented yet.
-    // TODO(https://github.com/awslabs/smithy-rs/issues/1401)
-    val unsupportedPatternTraitOnStringShapeSet = walker
-        .walkShapes(service)
-        .asSequence()
-        .filterIsInstance<StringShape>()
-        .filterMapShapesToTraits(setOf(PatternTrait::class.java))
-        .map { (shape, patternTrait) -> UnsupportedPatternTraitOnStringShape(shape, patternTrait as PatternTrait) }
-        .toSet()
-
-    // 6. Range trait on any shape is used. It has not been implemented yet.
+    // 5. Range trait on any shape is used. It has not been implemented yet.
     // TODO(https://github.com/awslabs/smithy-rs/issues/1401)
     val unsupportedRangeTraitOnShapeSet = walker
         .walkShapes(service)
@@ -233,7 +217,6 @@ fun validateUnsupportedConstraints(model: Model, service: ServiceShape, codegenC
             unsupportedLengthTraitOnStreamingBlobShapeSet.map { it.intoLogMessage(codegenConfig.ignoreUnsupportedConstraints) } +
             unsupportedConstraintOnShapeReachableViaAnEventStreamSet.map { it.intoLogMessage(codegenConfig.ignoreUnsupportedConstraints) } +
             unsupportedLengthTraitOnCollectionOrOnBlobShapeSet.map { it.intoLogMessage(codegenConfig.ignoreUnsupportedConstraints) } +
-            unsupportedPatternTraitOnStringShapeSet.map { it.intoLogMessage(codegenConfig.ignoreUnsupportedConstraints) } +
             unsupportedRangeTraitOnShapeSet.map { it.intoLogMessage(codegenConfig.ignoreUnsupportedConstraints) }
 
     return ValidationResult(shouldAbort = messages.any { it.level == Level.SEVERE }, messages)

From b9206bf18b6659b27b596acee6c825d06ea96716 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 12:16:33 +0000
Subject: [PATCH 09/59] Fix test cases in `ConstraintsTest`

---
 .../codegen/server/smithy/ConstraintsTest.kt  | 37 +++++++++----------
 1 file changed, 17 insertions(+), 20 deletions(-)

diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ConstraintsTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ConstraintsTest.kt
index 80e2d93dae..dfd5e6c002 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ConstraintsTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ConstraintsTest.kt
@@ -26,63 +26,63 @@ class ConstraintsTest {
             version: "123",
             operations: [TestOperation]
         }
-        
+
         operation TestOperation {
             input: TestInputOutput,
             output: TestInputOutput,
         }
-        
+
         structure TestInputOutput {
             map: MapA,
-            
+
             recursive: RecursiveShape
         }
-        
+
         structure RecursiveShape {
             shape: RecursiveShape,
             mapB: MapB
         }
-        
+
         @length(min: 1, max: 69)
         map MapA {
             key: String,
             value: MapB
         }
-        
+
         map MapB {
             key: String,
             value: StructureA
         }
-        
+
         @uniqueItems
         list ListA {
             member: MyString
         }
-        
+
         @pattern("\\w+")
         string MyString
-        
+
         @length(min: 1, max: 69)
         string LengthString
-        
+
         structure StructureA {
             @range(min: 1, max: 69)
             int: Integer,
-            
+
             @required
             string: String
         }
-        
+
         // This shape is not in the service closure.
         structure StructureB {
             @pattern("\\w+")
             patternString: String,
-            
+
             @required
             requiredString: String,
-            
+
             mapA: MapA,
-            
+
             @length(min: 1, max: 5)
             mapAPrecedence: MapA
         }
@@ -94,7 +94,6 @@ class ConstraintsTest {
     private val mapA = model.lookup<MapShape>("test#MapA")
     private val mapB = model.lookup<MapShape>("test#MapB")
     private val listA = model.lookup<ListShape>("test#ListA")
-    private val myString = model.lookup<StringShape>("test#MyString")
     private val lengthString = model.lookup<StringShape>("test#LengthString")
     private val structA = model.lookup<StructureShape>("test#StructureA")
     private val structAInt = model.lookup<MemberShape>("test#StructureA\$int")
@@ -114,7 +113,7 @@ class ConstraintsTest {
 
     @Test
     fun `it should not detect unsupported constrained traits as constrained`() {
-        listOf(structAInt, structAString, myString).forAll {
+        listOf(structAInt, structAString).forAll {
             it.isDirectlyConstrained(symbolProvider) shouldBe false
         }
     }
@@ -123,9 +122,7 @@ class ConstraintsTest {
     fun `it should evaluate reachability of constrained shapes`() {
         mapA.canReachConstrainedShape(model, symbolProvider) shouldBe true
         structAInt.canReachConstrainedShape(model, symbolProvider) shouldBe false
-
-        // This should be true when we start supporting the `pattern` trait on string shapes.
-        listA.canReachConstrainedShape(model, symbolProvider) shouldBe false
+        listA.canReachConstrainedShape(model, symbolProvider) shouldBe true
 
         // All of these eventually reach `StructureA`, which is constrained because one of its members is `required`.
         testInputOutput.canReachConstrainedShape(model, symbolProvider) shouldBe true

From 1f3d763032f192088dcfa231dc62db1e0c5a4d3b Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 12:17:35 +0000
Subject: [PATCH 10/59] Remove test disallowing `@pattern` on strings

---
 ...ateUnsupportedConstraintsAreNotUsedTest.kt | 51 ++++++-------------
 1 file changed, 16 insertions(+), 35 deletions(-)

diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraintsAreNotUsedTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraintsAreNotUsedTest.kt
index 0624358ba3..ae1a0e3697 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraintsAreNotUsedTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraintsAreNotUsedTest.kt
@@ -22,12 +22,12 @@ internal class ValidateUnsupportedConstraintsAreNotUsedTest {
     private val baseModel =
         """
         namespace test
-        
+
         service TestService {
             version: "123",
             operations: [TestOperation]
         }
-        
+
         operation TestOperation {
             input: TestInputOutput,
             output: TestInputOutput,
@@ -44,7 +44,7 @@ internal class ValidateUnsupportedConstraintsAreNotUsedTest {
         val model =
             """
             $baseModel
-            
+
             structure TestInputOutput {
                 @required
                 requiredString: String
@@ -62,7 +62,7 @@ internal class ValidateUnsupportedConstraintsAreNotUsedTest {
         val model =
             """
             $baseModel
-            
+
             structure TestInputOutput {
                 @length(min: 1, max: 69)
                 lengthString: String
@@ -79,7 +79,7 @@ internal class ValidateUnsupportedConstraintsAreNotUsedTest {
         val model =
             """
             $baseModel
-            
+
             structure TestInputOutput {
                 @required
                 string: String
@@ -93,12 +93,12 @@ internal class ValidateUnsupportedConstraintsAreNotUsedTest {
     private val constraintTraitOnStreamingBlobShapeModel =
         """
         $baseModel
-        
+
         structure TestInputOutput {
             @required
             streamingBlob: StreamingBlob
         }
-        
+
         @streaming
         @length(min: 69)
         blob StreamingBlob
@@ -123,20 +123,20 @@ internal class ValidateUnsupportedConstraintsAreNotUsedTest {
         val model =
             """
             $baseModel
-            
+
             structure TestInputOutput {
                 eventStream: EventStream
             }
-            
+
             @streaming
             union EventStream {
                 message: Message
             }
-            
+
             structure Message {
                 lengthString: LengthString
             }
-            
+
             @length(min: 1)
             string LengthString
             """.asSmithyModel()
@@ -155,17 +155,17 @@ internal class ValidateUnsupportedConstraintsAreNotUsedTest {
         val model =
             """
             $baseModel
-            
+
             structure TestInputOutput {
                 collection: LengthCollection,
                 blob: LengthBlob
             }
-            
+
             @length(min: 1)
             list LengthCollection {
                 member: String
             }
-            
+
             @length(min: 1)
             blob LengthBlob
             """.asSmithyModel()
@@ -176,35 +176,16 @@ internal class ValidateUnsupportedConstraintsAreNotUsedTest {
         validationResult.messages.forSome { it.message shouldContain "The blob shape `test#LengthBlob` has the constraint trait `smithy.api#length` attached" }
     }
 
-    @Test
-    fun `it should detect when the pattern trait on string shapes is used`() {
-        val model =
-            """
-            $baseModel
-            
-            structure TestInputOutput {
-                patternString: PatternString
-            }
-            
-            @pattern("^[A-Za-z]+$")
-            string PatternString
-            """.asSmithyModel()
-        val validationResult = validateModel(model)
-
-        validationResult.messages shouldHaveSize 1
-        validationResult.messages[0].message shouldContain "The string shape `test#PatternString` has the constraint trait `smithy.api#pattern` attached"
-    }
-
     @Test
     fun `it should detect when the range trait is used`() {
         val model =
             """
             $baseModel
-            
+
             structure TestInputOutput {
                 rangeInteger: RangeInteger
             }
-            
+
             @range(min: 1)
             integer RangeInteger
             """.asSmithyModel()

From 838485bfa71e288b70913c1670c85c98ade7a384 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 12:18:29 +0000
Subject: [PATCH 11/59] Add first test case for `@pattern` on strings

---
 .../generators/ConstrainedStringGeneratorTest.kt    | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
index 75db6303f7..13e1c43f09 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
@@ -44,11 +44,12 @@ class ConstrainedStringGeneratorTest {
                 "👍👍👍", // These three emojis are three Unicode scalar values.
                 "👍👍👍👍",
             ),
+            Triple("@pattern(\"^[a-z]+$\")", "valid", "123 invalid"),
         ).map {
             TestCase(
                 """
                 namespace test
-                
+
                 ${it.first}
                 string ConstrainedString
                 """.asSmithyModel(),
@@ -116,10 +117,10 @@ class ConstrainedStringGeneratorTest {
     fun `type should not be constructible without using a constructor`() {
         val model = """
             namespace test
-            
+
             @length(min: 1, max: 69)
             string ConstrainedString
-            """.asSmithyModel()
+        """.asSmithyModel()
         val constrainedStringShape = model.lookup<StringShape>("test#ConstrainedString")
 
         val codegenContext = serverTestCodegenContext(model)
@@ -136,14 +137,14 @@ class ConstrainedStringGeneratorTest {
     fun `Display implementation`() {
         val model = """
             namespace test
-            
+
             @length(min: 1, max: 69)
             string ConstrainedString
-            
+
             @sensitive
             @length(min: 1, max: 78)
             string SensitiveConstrainedString
-            """.asSmithyModel()
+        """.asSmithyModel()
         val constrainedStringShape = model.lookup<StringShape>("test#ConstrainedString")
         val sensitiveConstrainedStringShape = model.lookup<StringShape>("test#SensitiveConstrainedString")
 

From 1aa257345df402e6cb2b0dd7af98e7506eb0d4c7 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 12:22:31 +0000
Subject: [PATCH 12/59] Fix codegen in
 `ConstraintViolation::as_validation_exception_field`

---
 .../server/smithy/generators/ConstrainedStringGenerator.kt    | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 3edc811a42..a3e8781cd2 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -245,11 +245,11 @@ class ConstrainedStringGenerator(
                             ${if (lengthTrait != null) """Self::Length(length) => crate::model::ValidationExceptionField {
                                 message: format!("${lengthTrait.validationErrorMessage()}", length, &path),
                                 path,
-                            }""" else ""},
+                            },""" else ""}
                             ${ if (patternTrait != null) """Self::Pattern(pattern) => crate::model::ValidationExceptionField {
                                 message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
                                 path
-                            }""" else ""}
+                            },""" else ""}
                             """,
                         )
                     }

From d4de23465ddb6e3f5da1318f369ddad58bd3f5db Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 12:38:25 +0000
Subject: [PATCH 13/59] Use `OnceCell` to store `@pattern`'s regex

---
 .../server/smithy/generators/ConstrainedStringGenerator.kt    | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index a3e8781cd2..27e0640bc8 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -83,7 +83,8 @@ class ConstrainedStringGenerator(
         writer.rustTemplate(
             """
             fn check_pattern(string: &str) -> Result<(), $constraintViolation> {
-                let regex = #{Regex}::Regex::new("$pattern").unwrap();
+                static REGEX : #{OnceCell}::sync::OnceCell<#{Regex}::Regex> = #{OnceCell}::sync::OnceCell::new();
+                let regex = REGEX.get_or_init(|| #{Regex}::Regex::new("$pattern").unwrap());
 
                 if regex.is_match(string) {
                     Ok(())
@@ -93,6 +94,7 @@ class ConstrainedStringGenerator(
             }
             """.trimIndent(),
             "Regex" to ServerCargoDependency.Regex.asType(),
+            "OnceCell" to ServerCargoDependency.OnceCell.asType(),
         )
     }
     private fun renderTryFrom(inner: String, name: String, shape: StringShape, constraintViolation: Symbol) {

From be244073b3959edcc1afcd802c447c035c6db8eb Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 14:42:54 +0000
Subject: [PATCH 14/59] Tidy up `ConstrainedStringGenerator` to work with many
 constraints

---
 .../server/smithy/ServerCodegenVisitor.kt     |   6 +-
 .../generators/ConstrainedStringGenerator.kt  | 221 ++++++++++--------
 2 files changed, 128 insertions(+), 99 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt
index c0a68a26b7..444de52392 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt
@@ -22,6 +22,7 @@ import software.amazon.smithy.model.shapes.StructureShape
 import software.amazon.smithy.model.shapes.UnionShape
 import software.amazon.smithy.model.traits.EnumTrait
 import software.amazon.smithy.model.traits.LengthTrait
+import software.amazon.smithy.model.traits.PatternTrait
 import software.amazon.smithy.model.transform.ModelTransformer
 import software.amazon.smithy.rust.codegen.client.smithy.customize.RustCodegenDecorator
 import software.amazon.smithy.rust.codegen.core.rustlang.RustModule
@@ -41,6 +42,7 @@ import software.amazon.smithy.rust.codegen.core.smithy.transformers.EventStreamN
 import software.amazon.smithy.rust.codegen.core.smithy.transformers.OperationNormalizer
 import software.amazon.smithy.rust.codegen.core.smithy.transformers.RecursiveShapeBoxer
 import software.amazon.smithy.rust.codegen.core.util.CommandFailed
+import software.amazon.smithy.rust.codegen.core.util.getTrait
 import software.amazon.smithy.rust.codegen.core.util.hasTrait
 import software.amazon.smithy.rust.codegen.core.util.runCommand
 import software.amazon.smithy.rust.codegen.server.smithy.generators.ConstrainedMapGenerator
@@ -384,9 +386,11 @@ open class ServerCodegenVisitor(
                 """.trimIndent().replace("\n", " "),
             )
         } else if (!shape.hasTrait<EnumTrait>() && shape.isDirectlyConstrained(codegenContext.symbolProvider)) {
+            // TODO: Tidy up
+            val constraints = listOfNotNull(shape.getTrait<LengthTrait>(), shape.getTrait<PatternTrait>())
             logger.info("[rust-server-codegen] Generating a constrained string $shape")
             rustCrate.withModule(ModelsModule) {
-                ConstrainedStringGenerator(codegenContext, this, shape).render()
+                ConstrainedStringGenerator(codegenContext, this, shape, constraints).render()
             }
         }
     }
diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 27e0640bc8..e37a1e1f9a 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -7,6 +7,7 @@ package software.amazon.smithy.rust.codegen.server.smithy.generators
 
 import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.model.shapes.StringShape
+import software.amazon.smithy.model.traits.AbstractTrait
 import software.amazon.smithy.model.traits.LengthTrait
 import software.amazon.smithy.model.traits.PatternTrait
 import software.amazon.smithy.rust.codegen.core.rustlang.Attribute
@@ -24,7 +25,6 @@ import software.amazon.smithy.rust.codegen.core.rustlang.rustBlockTemplate
 import software.amazon.smithy.rust.codegen.core.rustlang.rustTemplate
 import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
 import software.amazon.smithy.rust.codegen.core.smithy.makeMaybeConstrained
-import software.amazon.smithy.rust.codegen.core.util.getTrait
 import software.amazon.smithy.rust.codegen.core.util.redactIfNecessary
 import software.amazon.smithy.rust.codegen.server.smithy.PubCrateConstraintViolationSymbolProvider
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCargoDependency
@@ -32,6 +32,97 @@ import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
 import software.amazon.smithy.rust.codegen.server.smithy.traits.isReachableFromOperationInput
 import software.amazon.smithy.rust.codegen.server.smithy.validationErrorMessage
 
+private data class TraitInfo(
+    val tryFromCheck: (writer: RustWriter) -> Unit,
+    val renderConstraintViolationVariant: (writer: RustWriter) -> Unit,
+    val asValidationExceptionField: (writer: RustWriter) -> Unit,
+    val renderValidationFunctionDefinition: (writer: RustWriter) -> Unit,
+)
+private fun handleTrait(trait: AbstractTrait, constraintViolation: Symbol): TraitInfo? {
+    when (trait) {
+        is LengthTrait -> {
+            return TraitInfo(
+                { writer -> writer.rust("Self::check_length(&value)?;") },
+                { writer -> writer.rust("Length(usize),") },
+                { writer ->
+                    writer.rust(
+                        """
+                        Self::Length(length) => crate::model::ValidationExceptionField {
+                            message: format!("${trait.validationErrorMessage()}", length, &path),
+                            path,
+                        },
+                        """.trimIndent(),
+                    )
+                },
+                { writer -> renderLengthValidation(writer, trait, constraintViolation) },
+            )
+        }
+        is PatternTrait -> {
+            return TraitInfo(
+                { writer -> writer.rust("Self::check_pattern(&value)?;") },
+                { writer -> writer.rust("Pattern(String),") },
+                { writer ->
+                    writer.rust(
+                        """
+                        Self::Pattern(pattern) => crate::model::ValidationExceptionField {
+                            message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
+                            path
+                        },
+                        """.trimIndent(),
+                    )
+                },
+                { writer -> renderPatternValidation(writer, trait, constraintViolation) },
+            )
+        }
+        else -> {
+            return null
+        }
+    }
+}
+
+private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait, constraintViolation: Symbol) {
+    val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
+        "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
+    } else if (lengthTrait.min.isPresent) {
+        "${lengthTrait.min.get()} <= length"
+    } else {
+        "length <= ${lengthTrait.max.get()}"
+    }
+    writer.rust(
+        """
+        fn check_length(string: &str) -> Result<(), $constraintViolation> {
+            let length = string.chars().count();
+
+            if $condition {
+                Ok(())
+            } else {
+                Err($constraintViolation::Length(length))
+            }
+        }
+        """.trimIndent(),
+    )
+}
+private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
+    val pattern = patternTrait.pattern.toString()
+
+    writer.rustTemplate(
+        """
+        fn check_pattern(string: &str) -> Result<(), $constraintViolation> {
+            static REGEX : #{OnceCell}::sync::OnceCell<#{Regex}::Regex> = #{OnceCell}::sync::OnceCell::new();
+            let regex = REGEX.get_or_init(|| #{Regex}::Regex::new("$pattern").unwrap());
+
+            if regex.is_match(string) {
+                Ok(())
+            } else {
+                Err($constraintViolation::Pattern("$pattern".to_owned()))
+            }
+        }
+        """.trimIndent(),
+        "Regex" to ServerCargoDependency.Regex.asType(),
+        "OnceCell" to ServerCargoDependency.OnceCell.asType(),
+    )
+}
+
 /**
  * [ConstrainedStringGenerator] generates a wrapper tuple newtype holding a constrained `String`.
  * This type can be built from unconstrained values, yielding a `ConstraintViolation` when the input does not satisfy
@@ -41,6 +132,7 @@ class ConstrainedStringGenerator(
     val codegenContext: ServerCodegenContext,
     val writer: RustWriter,
     val shape: StringShape,
+    val constraints: List<AbstractTrait>,
 ) {
     val model = codegenContext.model
     val constrainedShapeSymbolProvider = codegenContext.constrainedShapeSymbolProvider
@@ -54,85 +146,27 @@ class ConstrainedStringGenerator(
             }
         }
 
-    private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait, constraintViolation: Symbol) {
-        val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
-            "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
-        } else if (lengthTrait.min.isPresent) {
-            "${lengthTrait.min.get()} <= length"
-        } else {
-            "length <= ${lengthTrait.max.get()}"
-        }
-        writer.rust(
-            """
-            fn check_length(string: &str) -> Result<(), $constraintViolation> {
-                let length = string.chars().count();
-
-                if $condition {
-                    Ok(())
-                } else {
-                    Err($constraintViolation::Length(length))
-                }
-            }
-            """.trimIndent(),
-        )
-    }
-
-    private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
-        val pattern = patternTrait.pattern.toString()
-
-        writer.rustTemplate(
-            """
-            fn check_pattern(string: &str) -> Result<(), $constraintViolation> {
-                static REGEX : #{OnceCell}::sync::OnceCell<#{Regex}::Regex> = #{OnceCell}::sync::OnceCell::new();
-                let regex = REGEX.get_or_init(|| #{Regex}::Regex::new("$pattern").unwrap());
-
-                if regex.is_match(string) {
-                    Ok(())
-                } else {
-                    Err($constraintViolation::Pattern("$pattern".to_owned()))
-                }
-            }
-            """.trimIndent(),
-            "Regex" to ServerCargoDependency.Regex.asType(),
-            "OnceCell" to ServerCargoDependency.OnceCell.asType(),
-        )
-    }
-    private fun renderTryFrom(inner: String, name: String, shape: StringShape, constraintViolation: Symbol) {
-        val lengthTrait = shape.getTrait<LengthTrait>()
-        val patternTrait = shape.getTrait<PatternTrait>()
-
-        var lengthCheck = ""
-        if (lengthTrait != null) {
-            lengthCheck = "Self::check_length(&value)?;"
-
-            writer.rustBlock("impl $name") {
-                renderLengthValidation(writer, lengthTrait, constraintViolation)
-            }
-        }
-
-        var patternCheck = ""
-        if (patternTrait != null) {
-            patternCheck = "Self::check_pattern(&value)?;"
-            writer.rustBlock("impl $name") {
-                renderPatternValidation(writer, patternTrait, constraintViolation)
+    private fun renderTryFrom(inner: String, name: String, constraintViolation: Symbol, traits: List<TraitInfo>) {
+        writer.rustBlock("impl $name") {
+            for (traitInfo in traits) {
+                traitInfo.renderValidationFunctionDefinition(writer)
             }
         }
-        writer.rustTemplate(
-            """
-            impl #{TryFrom}<$inner> for $name {
-                type Error = #{ConstraintViolation};
 
+        writer.rustBlockTemplate("impl #{TryFrom}<$inner> for $name", "TryFrom" to RuntimeType.TryFrom) {
+            rustTemplate("type Error = #{ConstraintViolation};", "ConstraintViolation" to constraintViolation)
+            rustBlock(
+                """
                 /// ${rustDocsTryFromMethod(name, inner)}
-                fn try_from(value: $inner) -> Result<Self, Self::Error> {
-                    $lengthCheck
-                    $patternCheck
-                    Ok(Self(value))
+                fn try_from(value: $inner) -> Result<Self, Self::Error>
+                """,
+            ) {
+                for (traitInfo in traits) {
+                    traitInfo.tryFromCheck(writer)
                 }
+                rust("Ok(Self(value))")
             }
-            """.trimIndent(),
-            "ConstraintViolation" to constraintViolation,
-            "TryFrom" to RuntimeType.TryFrom,
-        )
+        }
     }
 
     fun render() {
@@ -181,7 +215,9 @@ class ConstrainedStringGenerator(
             )
         }
 
-        renderTryFrom(inner, name, shape, constraintViolation)
+        val traits: List<TraitInfo> = constraints.mapNotNull { handleTrait(it, constraintViolation) }
+
+        renderTryFrom(inner, name, constraintViolation, traits)
 
         writer.rustTemplate(
             """
@@ -217,23 +253,21 @@ class ConstrainedStringGenerator(
 
         val constraintViolationModuleName = constraintViolation.namespace.split(constraintViolation.namespaceDelimiter).last()
         writer.withModule(RustModule(constraintViolationModuleName, RustMetadata(visibility = constrainedTypeVisibility))) {
-            renderConstraintViolationEnum(this, shape, constraintViolation)
+            renderConstraintViolationEnum(this, shape, constraintViolation, traits)
         }
     }
 
-    private fun renderConstraintViolationEnum(writer: RustWriter, shape: StringShape, constraintViolation: Symbol) {
-        val lengthTrait = shape.getTrait<LengthTrait>()
-        val patternTrait = shape.getTrait<PatternTrait>()
-
-        writer.rust(
+    private fun renderConstraintViolationEnum(writer: RustWriter, shape: StringShape, constraintViolation: Symbol, constraintTraits: List<TraitInfo>) {
+        writer.rustBlock(
             """
             ##[derive(Debug, PartialEq)]
-            pub enum ${constraintViolation.name} {
-                ${if (lengthTrait != null) "Length(usize)," else ""}
-                ${if (patternTrait != null) "Pattern(String)," else ""}
+            pub enum ${constraintViolation.name}
+            """.trimIndent(),
+        ) {
+            for (traitInfo in constraintTraits) {
+                traitInfo.renderConstraintViolationVariant(this)
             }
-            """,
-        )
+        }
 
         if (shape.isReachableFromOperationInput()) {
             writer.rustBlock("impl ${constraintViolation.name}") {
@@ -242,18 +276,9 @@ class ConstrainedStringGenerator(
                     "String" to RuntimeType.String,
                 ) {
                     rustBlock("match self") {
-                        rust(
-                            """
-                            ${if (lengthTrait != null) """Self::Length(length) => crate::model::ValidationExceptionField {
-                                message: format!("${lengthTrait.validationErrorMessage()}", length, &path),
-                                path,
-                            },""" else ""}
-                            ${ if (patternTrait != null) """Self::Pattern(pattern) => crate::model::ValidationExceptionField {
-                                message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
-                                path
-                            },""" else ""}
-                            """,
-                        )
+                        for (traitInfo in constraintTraits) {
+                            traitInfo.asValidationExceptionField(this)
+                        }
                     }
                 }
             }

From 77637fd40c4e817554178159044f6d90cc3f75ef Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 14:52:46 +0000
Subject: [PATCH 15/59] Rename `handleTrait` -> `fromTrait` and make it a
 static method

---
 .../generators/ConstrainedStringGenerator.kt  | 101 ++++++++++--------
 1 file changed, 54 insertions(+), 47 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index e37a1e1f9a..dfa0177fd9 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -32,50 +32,58 @@ import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
 import software.amazon.smithy.rust.codegen.server.smithy.traits.isReachableFromOperationInput
 import software.amazon.smithy.rust.codegen.server.smithy.validationErrorMessage
 
+/**
+ * Information needed to render a constraint trait as Rust code.
+ */
 private data class TraitInfo(
     val tryFromCheck: (writer: RustWriter) -> Unit,
     val renderConstraintViolationVariant: (writer: RustWriter) -> Unit,
     val asValidationExceptionField: (writer: RustWriter) -> Unit,
-    val renderValidationFunctionDefinition: (writer: RustWriter) -> Unit,
-)
-private fun handleTrait(trait: AbstractTrait, constraintViolation: Symbol): TraitInfo? {
-    when (trait) {
-        is LengthTrait -> {
-            return TraitInfo(
-                { writer -> writer.rust("Self::check_length(&value)?;") },
-                { writer -> writer.rust("Length(usize),") },
-                { writer ->
-                    writer.rust(
-                        """
-                        Self::Length(length) => crate::model::ValidationExceptionField {
-                            message: format!("${trait.validationErrorMessage()}", length, &path),
-                            path,
+    val renderValidationFunctionDefinition: (writer: RustWriter, constraintViolation: Symbol) -> Unit,
+) {
+    companion object {
+        fun fromTrait(trait: AbstractTrait): TraitInfo? {
+            when (trait) {
+                is LengthTrait -> {
+                    return TraitInfo(
+                        { writer -> writer.rust("Self::check_length(&value)?;") },
+                        { writer -> writer.rust("Length(usize),") },
+                        { writer ->
+                            writer.rust(
+                                """
+                                Self::Length(length) => crate::model::ValidationExceptionField {
+                                    message: format!("${trait.validationErrorMessage()}", length, &path),
+                                    path,
+                                },
+                                """.trimIndent(),
+                            )
                         },
-                        """.trimIndent(),
+                        { writer, constraintViolation -> renderLengthValidation(writer, trait, constraintViolation) },
                     )
-                },
-                { writer -> renderLengthValidation(writer, trait, constraintViolation) },
-            )
-        }
-        is PatternTrait -> {
-            return TraitInfo(
-                { writer -> writer.rust("Self::check_pattern(&value)?;") },
-                { writer -> writer.rust("Pattern(String),") },
-                { writer ->
-                    writer.rust(
-                        """
-                        Self::Pattern(pattern) => crate::model::ValidationExceptionField {
-                            message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
-                            path
+                }
+
+                is PatternTrait -> {
+                    return TraitInfo(
+                        { writer -> writer.rust("Self::check_pattern(&value)?;") },
+                        { writer -> writer.rust("Pattern(String),") },
+                        { writer ->
+                            writer.rust(
+                                """
+                                Self::Pattern(pattern) => crate::model::ValidationExceptionField {
+                                    message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
+                                    path
+                                },
+                                """.trimIndent(),
+                            )
                         },
-                        """.trimIndent(),
+                        { writer, constraintViolation -> renderPatternValidation(writer, trait, constraintViolation) },
                     )
-                },
-                { writer -> renderPatternValidation(writer, trait, constraintViolation) },
-            )
-        }
-        else -> {
-            return null
+                }
+
+                else -> {
+                    return null
+                }
+            }
         }
     }
 }
@@ -146,10 +154,10 @@ class ConstrainedStringGenerator(
             }
         }
 
-    private fun renderTryFrom(inner: String, name: String, constraintViolation: Symbol, traits: List<TraitInfo>) {
+    private fun renderTryFrom(inner: String, name: String, constraintViolation: Symbol, constraintsInfo: List<TraitInfo>) {
         writer.rustBlock("impl $name") {
-            for (traitInfo in traits) {
-                traitInfo.renderValidationFunctionDefinition(writer)
+            for (traitInfo in constraintsInfo) {
+                traitInfo.renderValidationFunctionDefinition(writer, constraintViolation)
             }
         }
 
@@ -161,7 +169,7 @@ class ConstrainedStringGenerator(
                 fn try_from(value: $inner) -> Result<Self, Self::Error>
                 """,
             ) {
-                for (traitInfo in traits) {
+                for (traitInfo in constraintsInfo) {
                     traitInfo.tryFromCheck(writer)
                 }
                 rust("Ok(Self(value))")
@@ -174,6 +182,7 @@ class ConstrainedStringGenerator(
         val name = symbol.name
         val inner = RustType.String.render()
         val constraintViolation = constraintViolationSymbolProvider.toSymbol(shape)
+        val constraintsInfo: List<TraitInfo> = constraints.mapNotNull(TraitInfo::fromTrait)
 
         val constrainedTypeVisibility = if (publicConstrainedTypes) {
             Visibility.PUBLIC
@@ -215,9 +224,7 @@ class ConstrainedStringGenerator(
             )
         }
 
-        val traits: List<TraitInfo> = constraints.mapNotNull { handleTrait(it, constraintViolation) }
-
-        renderTryFrom(inner, name, constraintViolation, traits)
+        renderTryFrom(inner, name, constraintViolation, constraintsInfo)
 
         writer.rustTemplate(
             """
@@ -253,18 +260,18 @@ class ConstrainedStringGenerator(
 
         val constraintViolationModuleName = constraintViolation.namespace.split(constraintViolation.namespaceDelimiter).last()
         writer.withModule(RustModule(constraintViolationModuleName, RustMetadata(visibility = constrainedTypeVisibility))) {
-            renderConstraintViolationEnum(this, shape, constraintViolation, traits)
+            renderConstraintViolationEnum(this, shape, constraintViolation, constraintsInfo)
         }
     }
 
-    private fun renderConstraintViolationEnum(writer: RustWriter, shape: StringShape, constraintViolation: Symbol, constraintTraits: List<TraitInfo>) {
+    private fun renderConstraintViolationEnum(writer: RustWriter, shape: StringShape, constraintViolation: Symbol, constraintsInfo: List<TraitInfo>) {
         writer.rustBlock(
             """
             ##[derive(Debug, PartialEq)]
             pub enum ${constraintViolation.name}
             """.trimIndent(),
         ) {
-            for (traitInfo in constraintTraits) {
+            for (traitInfo in constraintsInfo) {
                 traitInfo.renderConstraintViolationVariant(this)
             }
         }
@@ -276,7 +283,7 @@ class ConstrainedStringGenerator(
                     "String" to RuntimeType.String,
                 ) {
                     rustBlock("match self") {
-                        for (traitInfo in constraintTraits) {
+                        for (traitInfo in constraintsInfo) {
                             traitInfo.asValidationExceptionField(this)
                         }
                     }

From aae0b755ed34b6df36f6543a2c4e21e8230d8490 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 14:55:29 +0000
Subject: [PATCH 16/59] Add docs for `ConstraintViolation` variants

---
 .../smithy/generators/ConstrainedStringGenerator.kt   | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index dfa0177fd9..5397dd5789 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -17,6 +17,7 @@ import software.amazon.smithy.rust.codegen.core.rustlang.RustType
 import software.amazon.smithy.rust.codegen.core.rustlang.RustWriter
 import software.amazon.smithy.rust.codegen.core.rustlang.Visibility
 import software.amazon.smithy.rust.codegen.core.rustlang.asType
+import software.amazon.smithy.rust.codegen.core.rustlang.docs
 import software.amazon.smithy.rust.codegen.core.rustlang.documentShape
 import software.amazon.smithy.rust.codegen.core.rustlang.render
 import software.amazon.smithy.rust.codegen.core.rustlang.rust
@@ -47,7 +48,10 @@ private data class TraitInfo(
                 is LengthTrait -> {
                     return TraitInfo(
                         { writer -> writer.rust("Self::check_length(&value)?;") },
-                        { writer -> writer.rust("Length(usize),") },
+                        { writer ->
+                            writer.docs("Error when a string doesn't satisfy its `@length` requirements.")
+                            writer.rust("Length(usize),")
+                        },
                         { writer ->
                             writer.rust(
                                 """
@@ -65,7 +69,10 @@ private data class TraitInfo(
                 is PatternTrait -> {
                     return TraitInfo(
                         { writer -> writer.rust("Self::check_pattern(&value)?;") },
-                        { writer -> writer.rust("Pattern(String),") },
+                        { writer ->
+                            writer.docs("Error when a string doesn't satisfy its `@pattern`.")
+                            writer.rust("Pattern(String),")
+                        },
                         { writer ->
                             writer.rust(
                                 """

From 116e9dea874e7c5fbb41c9e63edde132872f4d61 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 14:58:41 +0000
Subject: [PATCH 17/59] Fix unescaped slashes in regexes

---
 .../server/smithy/generators/ConstrainedStringGenerator.kt    | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 5397dd5789..92e46e00aa 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -118,7 +118,9 @@ private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait,
     )
 }
 private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
-    val pattern = patternTrait.pattern.toString()
+    // Escape `\`s to not end up with broken rust code in the presence of regexes with slashes.
+    // This turns `Regex::new("^[\S\s]+$")` into `Regex::new("^[\\S\\s]+$")`.
+    val pattern = patternTrait.pattern.toString().replace("\\", "\\\\")
 
     writer.rustTemplate(
         """

From 55df743b52d38940a724323617177dae3fe74ca1 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Thu, 17 Nov 2022 16:17:09 +0000
Subject: [PATCH 18/59] Quick hack to get tests compiling

---
 .../server/smithy/ServerCodegenVisitor.kt     |  1 -
 .../ConstrainedStringGeneratorTest.kt         | 20 +++++++++++--------
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt
index 444de52392..2f87f6b1d9 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt
@@ -386,7 +386,6 @@ open class ServerCodegenVisitor(
                 """.trimIndent().replace("\n", " "),
             )
         } else if (!shape.hasTrait<EnumTrait>() && shape.isDirectlyConstrained(codegenContext.symbolProvider)) {
-            // TODO: Tidy up
             val constraints = listOfNotNull(shape.getTrait<LengthTrait>(), shape.getTrait<PatternTrait>())
             logger.info("[rust-server-codegen] Generating a constrained string $shape")
             rustCrate.withModule(ModelsModule) {
diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
index 13e1c43f09..2dc8925fc7 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
@@ -14,22 +14,25 @@ import org.junit.jupiter.params.provider.ArgumentsProvider
 import org.junit.jupiter.params.provider.ArgumentsSource
 import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.shapes.StringShape
+import software.amazon.smithy.model.traits.LengthTrait
+import software.amazon.smithy.model.traits.PatternTrait
 import software.amazon.smithy.rust.codegen.core.rustlang.RustWriter
 import software.amazon.smithy.rust.codegen.core.smithy.ModelsModule
 import software.amazon.smithy.rust.codegen.core.testutil.TestWorkspace
 import software.amazon.smithy.rust.codegen.core.testutil.asSmithyModel
 import software.amazon.smithy.rust.codegen.core.testutil.compileAndTest
 import software.amazon.smithy.rust.codegen.core.testutil.unitTest
+import software.amazon.smithy.rust.codegen.core.util.expectTrait
 import software.amazon.smithy.rust.codegen.core.util.lookup
 import software.amazon.smithy.rust.codegen.server.smithy.testutil.serverTestCodegenContext
 import java.util.stream.Stream
 
 class ConstrainedStringGeneratorTest {
-
+    val a = PatternTrait("something")
     data class TestCase(val model: Model, val validString: String, val invalidString: String)
 
     class ConstrainedStringGeneratorTestProvider : ArgumentsProvider {
-        private val testCases = listOf(
+        private val lengthTestCases = listOf(
             // Min and max.
             Triple("@length(min: 11, max: 12)", "validString", "invalidString"),
             // Min equal to max.
@@ -44,7 +47,8 @@ class ConstrainedStringGeneratorTest {
                 "👍👍👍", // These three emojis are three Unicode scalar values.
                 "👍👍👍👍",
             ),
-            Triple("@pattern(\"^[a-z]+$\")", "valid", "123 invalid"),
+            // Need to fix the setup to be able to add `@pattern` tests.
+            // Triple("@pattern(\"^[a-z]+$\")", "valid", "123 invalid"),
         ).map {
             TestCase(
                 """
@@ -59,7 +63,7 @@ class ConstrainedStringGeneratorTest {
         }
 
         override fun provideArguments(context: ExtensionContext?): Stream<out Arguments> =
-            testCases.map { Arguments.of(it) }.stream()
+            lengthTestCases.map { Arguments.of(it) }.stream()
     }
 
     @ParameterizedTest
@@ -73,7 +77,7 @@ class ConstrainedStringGeneratorTest {
         val project = TestWorkspace.testProject(symbolProvider)
 
         project.withModule(ModelsModule) {
-            ConstrainedStringGenerator(codegenContext, this, constrainedStringShape).render()
+            ConstrainedStringGenerator(codegenContext, this, constrainedStringShape, listOf(constrainedStringShape.expectTrait<LengthTrait>())).render()
 
             unitTest(
                 name = "try_from_success",
@@ -127,7 +131,7 @@ class ConstrainedStringGeneratorTest {
 
         val writer = RustWriter.forModule(ModelsModule.name)
 
-        ConstrainedStringGenerator(codegenContext, writer, constrainedStringShape).render()
+        ConstrainedStringGenerator(codegenContext, writer, constrainedStringShape, listOf(constrainedStringShape.expectTrait<LengthTrait>())).render()
 
         // Check that the wrapped type is `pub(crate)`.
         writer.toString() shouldContain "pub struct ConstrainedString(pub(crate) std::string::String);"
@@ -153,8 +157,8 @@ class ConstrainedStringGeneratorTest {
         val project = TestWorkspace.testProject(codegenContext.symbolProvider)
 
         project.withModule(ModelsModule) {
-            ConstrainedStringGenerator(codegenContext, this, constrainedStringShape).render()
-            ConstrainedStringGenerator(codegenContext, this, sensitiveConstrainedStringShape).render()
+            ConstrainedStringGenerator(codegenContext, this, constrainedStringShape, listOf(constrainedStringShape.expectTrait<LengthTrait>())).render()
+            ConstrainedStringGenerator(codegenContext, this, sensitiveConstrainedStringShape, listOf(constrainedStringShape.expectTrait<LengthTrait>())).render()
 
             unitTest(
                 name = "non_sensitive_string_display_implementation",

From 67863ca7ef12f95d354adaa8e8717285dc6e5e3e Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 09:46:45 +0000
Subject: [PATCH 19/59] Fix `sensitive_string_display_implementation` test

---
 .../server/smithy/generators/ConstrainedStringGeneratorTest.kt  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
index 2dc8925fc7..3c6b61717b 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
@@ -158,7 +158,7 @@ class ConstrainedStringGeneratorTest {
 
         project.withModule(ModelsModule) {
             ConstrainedStringGenerator(codegenContext, this, constrainedStringShape, listOf(constrainedStringShape.expectTrait<LengthTrait>())).render()
-            ConstrainedStringGenerator(codegenContext, this, sensitiveConstrainedStringShape, listOf(constrainedStringShape.expectTrait<LengthTrait>())).render()
+            ConstrainedStringGenerator(codegenContext, this, sensitiveConstrainedStringShape, listOf(sensitiveConstrainedStringShape.expectTrait<LengthTrait>())).render()
 
             unitTest(
                 name = "non_sensitive_string_display_implementation",

From 96ea2c72b023d0451f7d13e9940b2ff0270271de Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 10:05:39 +0000
Subject: [PATCH 20/59] Use new fn name: `asType` -> `toType`

---
 .../server/smithy/generators/ConstrainedStringGenerator.kt   | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 92e46e00aa..085612cf09 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -16,7 +16,6 @@ import software.amazon.smithy.rust.codegen.core.rustlang.RustModule
 import software.amazon.smithy.rust.codegen.core.rustlang.RustType
 import software.amazon.smithy.rust.codegen.core.rustlang.RustWriter
 import software.amazon.smithy.rust.codegen.core.rustlang.Visibility
-import software.amazon.smithy.rust.codegen.core.rustlang.asType
 import software.amazon.smithy.rust.codegen.core.rustlang.docs
 import software.amazon.smithy.rust.codegen.core.rustlang.documentShape
 import software.amazon.smithy.rust.codegen.core.rustlang.render
@@ -135,8 +134,8 @@ private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTra
             }
         }
         """.trimIndent(),
-        "Regex" to ServerCargoDependency.Regex.asType(),
-        "OnceCell" to ServerCargoDependency.OnceCell.asType(),
+        "Regex" to ServerCargoDependency.Regex.toType(),
+        "OnceCell" to ServerCargoDependency.OnceCell.toType(),
     )
 }
 

From 275e2a88368e19d4e51c4865bb1e74e4dbebe874 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 10:20:26 +0000
Subject: [PATCH 21/59] Refactor `ConstrainedStringGenerator` to not pass in
 `constraints`

---
 .../server/smithy/ServerCodegenVisitor.kt     |  5 +---
 .../generators/ConstrainedStringGenerator.kt  | 26 ++++++++++++++-----
 .../ConstrainedStringGeneratorTest.kt         | 10 +++----
 3 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt
index dc947e8003..8a3c5649bc 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt
@@ -22,7 +22,6 @@ import software.amazon.smithy.model.shapes.StructureShape
 import software.amazon.smithy.model.shapes.UnionShape
 import software.amazon.smithy.model.traits.EnumTrait
 import software.amazon.smithy.model.traits.LengthTrait
-import software.amazon.smithy.model.traits.PatternTrait
 import software.amazon.smithy.model.transform.ModelTransformer
 import software.amazon.smithy.rust.codegen.client.smithy.customize.RustCodegenDecorator
 import software.amazon.smithy.rust.codegen.core.rustlang.RustModule
@@ -42,7 +41,6 @@ import software.amazon.smithy.rust.codegen.core.smithy.transformers.EventStreamN
 import software.amazon.smithy.rust.codegen.core.smithy.transformers.OperationNormalizer
 import software.amazon.smithy.rust.codegen.core.smithy.transformers.RecursiveShapeBoxer
 import software.amazon.smithy.rust.codegen.core.util.CommandFailed
-import software.amazon.smithy.rust.codegen.core.util.getTrait
 import software.amazon.smithy.rust.codegen.core.util.hasTrait
 import software.amazon.smithy.rust.codegen.core.util.runCommand
 import software.amazon.smithy.rust.codegen.server.smithy.generators.ConstrainedMapGenerator
@@ -386,10 +384,9 @@ open class ServerCodegenVisitor(
                 """.trimIndent().replace("\n", " "),
             )
         } else if (!shape.hasTrait<EnumTrait>() && shape.isDirectlyConstrained(codegenContext.symbolProvider)) {
-            val constraints = listOfNotNull(shape.getTrait<LengthTrait>(), shape.getTrait<PatternTrait>())
             logger.info("[rust-server-codegen] Generating a constrained string $shape")
             rustCrate.withModule(ModelsModule) {
-                ConstrainedStringGenerator(codegenContext, this, shape, constraints).render()
+                ConstrainedStringGenerator(codegenContext, this, shape).render()
             }
         }
     }
diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 085612cf09..79b6e88a03 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -25,6 +25,7 @@ import software.amazon.smithy.rust.codegen.core.rustlang.rustBlockTemplate
 import software.amazon.smithy.rust.codegen.core.rustlang.rustTemplate
 import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
 import software.amazon.smithy.rust.codegen.core.smithy.makeMaybeConstrained
+import software.amazon.smithy.rust.codegen.core.util.orNull
 import software.amazon.smithy.rust.codegen.core.util.redactIfNecessary
 import software.amazon.smithy.rust.codegen.server.smithy.PubCrateConstraintViolationSymbolProvider
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCargoDependency
@@ -94,6 +95,10 @@ private data class TraitInfo(
     }
 }
 
+/**
+ * Renders a `check_length` function to validate the string matches the
+ * required length indicated by the `@length` trait.
+ */
 private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait, constraintViolation: Symbol) {
     val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
         "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
@@ -116,6 +121,11 @@ private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait,
         """.trimIndent(),
     )
 }
+
+/**
+ * Renders a `check_pattern` function to validate the string matches the
+ * supplied regex in the `@pattern` trait.
+ */
 private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
     // Escape `\`s to not end up with broken rust code in the presence of regexes with slashes.
     // This turns `Regex::new("^[\S\s]+$")` into `Regex::new("^[\\S\\s]+$")`.
@@ -139,6 +149,8 @@ private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTra
     )
 }
 
+private val supportedStringConstraintTraits = listOf(LengthTrait::class.java, PatternTrait::class.java)
+
 /**
  * [ConstrainedStringGenerator] generates a wrapper tuple newtype holding a constrained `String`.
  * This type can be built from unconstrained values, yielding a `ConstraintViolation` when the input does not satisfy
@@ -148,7 +160,6 @@ class ConstrainedStringGenerator(
     val codegenContext: ServerCodegenContext,
     val writer: RustWriter,
     val shape: StringShape,
-    val constraints: List<AbstractTrait>,
 ) {
     val model = codegenContext.model
     val constrainedShapeSymbolProvider = codegenContext.constrainedShapeSymbolProvider
@@ -161,8 +172,12 @@ class ConstrainedStringGenerator(
                 PubCrateConstraintViolationSymbolProvider(this)
             }
         }
+    private val constraintsInfo: List<TraitInfo> =
+        supportedStringConstraintTraits
+            .mapNotNull { shape.getTrait(it).orNull() }
+            .mapNotNull(TraitInfo::fromTrait)
 
-    private fun renderTryFrom(inner: String, name: String, constraintViolation: Symbol, constraintsInfo: List<TraitInfo>) {
+    private fun renderTryFrom(inner: String, name: String, constraintViolation: Symbol) {
         writer.rustBlock("impl $name") {
             for (traitInfo in constraintsInfo) {
                 traitInfo.renderValidationFunctionDefinition(writer, constraintViolation)
@@ -190,7 +205,6 @@ class ConstrainedStringGenerator(
         val name = symbol.name
         val inner = RustType.String.render()
         val constraintViolation = constraintViolationSymbolProvider.toSymbol(shape)
-        val constraintsInfo: List<TraitInfo> = constraints.mapNotNull(TraitInfo::fromTrait)
 
         val constrainedTypeVisibility = if (publicConstrainedTypes) {
             Visibility.PUBLIC
@@ -232,7 +246,7 @@ class ConstrainedStringGenerator(
             )
         }
 
-        renderTryFrom(inner, name, constraintViolation, constraintsInfo)
+        renderTryFrom(inner, name, constraintViolation)
 
         writer.rustTemplate(
             """
@@ -268,11 +282,11 @@ class ConstrainedStringGenerator(
 
         val constraintViolationModuleName = constraintViolation.namespace.split(constraintViolation.namespaceDelimiter).last()
         writer.withModule(RustModule(constraintViolationModuleName, RustMetadata(visibility = constrainedTypeVisibility))) {
-            renderConstraintViolationEnum(this, shape, constraintViolation, constraintsInfo)
+            renderConstraintViolationEnum(this, shape, constraintViolation)
         }
     }
 
-    private fun renderConstraintViolationEnum(writer: RustWriter, shape: StringShape, constraintViolation: Symbol, constraintsInfo: List<TraitInfo>) {
+    private fun renderConstraintViolationEnum(writer: RustWriter, shape: StringShape, constraintViolation: Symbol) {
         writer.rustBlock(
             """
             ##[derive(Debug, PartialEq)]
diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
index 3c6b61717b..409bdc4638 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
@@ -14,7 +14,6 @@ import org.junit.jupiter.params.provider.ArgumentsProvider
 import org.junit.jupiter.params.provider.ArgumentsSource
 import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.shapes.StringShape
-import software.amazon.smithy.model.traits.LengthTrait
 import software.amazon.smithy.model.traits.PatternTrait
 import software.amazon.smithy.rust.codegen.core.rustlang.RustWriter
 import software.amazon.smithy.rust.codegen.core.smithy.ModelsModule
@@ -22,7 +21,6 @@ import software.amazon.smithy.rust.codegen.core.testutil.TestWorkspace
 import software.amazon.smithy.rust.codegen.core.testutil.asSmithyModel
 import software.amazon.smithy.rust.codegen.core.testutil.compileAndTest
 import software.amazon.smithy.rust.codegen.core.testutil.unitTest
-import software.amazon.smithy.rust.codegen.core.util.expectTrait
 import software.amazon.smithy.rust.codegen.core.util.lookup
 import software.amazon.smithy.rust.codegen.server.smithy.testutil.serverTestCodegenContext
 import java.util.stream.Stream
@@ -77,7 +75,7 @@ class ConstrainedStringGeneratorTest {
         val project = TestWorkspace.testProject(symbolProvider)
 
         project.withModule(ModelsModule) {
-            ConstrainedStringGenerator(codegenContext, this, constrainedStringShape, listOf(constrainedStringShape.expectTrait<LengthTrait>())).render()
+            ConstrainedStringGenerator(codegenContext, this, constrainedStringShape).render()
 
             unitTest(
                 name = "try_from_success",
@@ -131,7 +129,7 @@ class ConstrainedStringGeneratorTest {
 
         val writer = RustWriter.forModule(ModelsModule.name)
 
-        ConstrainedStringGenerator(codegenContext, writer, constrainedStringShape, listOf(constrainedStringShape.expectTrait<LengthTrait>())).render()
+        ConstrainedStringGenerator(codegenContext, writer, constrainedStringShape).render()
 
         // Check that the wrapped type is `pub(crate)`.
         writer.toString() shouldContain "pub struct ConstrainedString(pub(crate) std::string::String);"
@@ -157,8 +155,8 @@ class ConstrainedStringGeneratorTest {
         val project = TestWorkspace.testProject(codegenContext.symbolProvider)
 
         project.withModule(ModelsModule) {
-            ConstrainedStringGenerator(codegenContext, this, constrainedStringShape, listOf(constrainedStringShape.expectTrait<LengthTrait>())).render()
-            ConstrainedStringGenerator(codegenContext, this, sensitiveConstrainedStringShape, listOf(sensitiveConstrainedStringShape.expectTrait<LengthTrait>())).render()
+            ConstrainedStringGenerator(codegenContext, this, constrainedStringShape).render()
+            ConstrainedStringGenerator(codegenContext, this, sensitiveConstrainedStringShape).render()
 
             unitTest(
                 name = "non_sensitive_string_display_implementation",

From 4ffd5503d6d8896faf0793a297c42b2af3cc712b Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 10:25:11 +0000
Subject: [PATCH 22/59] Add `@pattern` test

---
 .../server/smithy/generators/ConstrainedStringGeneratorTest.kt  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
index 409bdc4638..3ba301937c 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
@@ -46,7 +46,7 @@ class ConstrainedStringGeneratorTest {
                 "👍👍👍👍",
             ),
             // Need to fix the setup to be able to add `@pattern` tests.
-            // Triple("@pattern(\"^[a-z]+$\")", "valid", "123 invalid"),
+            Triple("@pattern(\"^[a-z]+$\")", "valid", "123 invalid"),
         ).map {
             TestCase(
                 """

From 0797f4dcd1e1b8e6911d8fcca4c29434d03d2855 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 13:27:27 +0000
Subject: [PATCH 23/59] Use `Lazy` instead of `OnceCell`

---
 .../server/smithy/generators/ConstrainedStringGenerator.kt   | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 79b6e88a03..ec4e50f759 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -134,10 +134,9 @@ private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTra
     writer.rustTemplate(
         """
         fn check_pattern(string: &str) -> Result<(), $constraintViolation> {
-            static REGEX : #{OnceCell}::sync::OnceCell<#{Regex}::Regex> = #{OnceCell}::sync::OnceCell::new();
-            let regex = REGEX.get_or_init(|| #{Regex}::Regex::new("$pattern").unwrap());
+            static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new("$pattern").unwrap());
 
-            if regex.is_match(string) {
+            if REGEX.is_match(string) {
                 Ok(())
             } else {
                 Err($constraintViolation::Pattern("$pattern".to_owned()))

From 22fd18f582fcfc3573f8f66cdfbb3ca89c8f7b9e Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 13:28:53 +0000
Subject: [PATCH 24/59] Store `&'static str` in `Pattern` error instead of
 `String`

---
 .../server/smithy/generators/ConstrainedStringGenerator.kt    | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index ec4e50f759..ecc5ff7872 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -71,7 +71,7 @@ private data class TraitInfo(
                         { writer -> writer.rust("Self::check_pattern(&value)?;") },
                         { writer ->
                             writer.docs("Error when a string doesn't satisfy its `@pattern`.")
-                            writer.rust("Pattern(String),")
+                            writer.rust("Pattern(&'static str),")
                         },
                         { writer ->
                             writer.rust(
@@ -139,7 +139,7 @@ private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTra
             if REGEX.is_match(string) {
                 Ok(())
             } else {
-                Err($constraintViolation::Pattern("$pattern".to_owned()))
+                Err($constraintViolation::Pattern("$pattern"))
             }
         }
         """.trimIndent(),

From 65139bd067c282cc8bd42fd66e287da85871e838 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 13:30:00 +0000
Subject: [PATCH 25/59] Move `TraitInfo` to the bottom

---
 .../generators/ConstrainedStringGenerator.kt  | 230 +++++++++---------
 1 file changed, 115 insertions(+), 115 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index ecc5ff7872..48f551f60d 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -33,121 +33,6 @@ import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
 import software.amazon.smithy.rust.codegen.server.smithy.traits.isReachableFromOperationInput
 import software.amazon.smithy.rust.codegen.server.smithy.validationErrorMessage
 
-/**
- * Information needed to render a constraint trait as Rust code.
- */
-private data class TraitInfo(
-    val tryFromCheck: (writer: RustWriter) -> Unit,
-    val renderConstraintViolationVariant: (writer: RustWriter) -> Unit,
-    val asValidationExceptionField: (writer: RustWriter) -> Unit,
-    val renderValidationFunctionDefinition: (writer: RustWriter, constraintViolation: Symbol) -> Unit,
-) {
-    companion object {
-        fun fromTrait(trait: AbstractTrait): TraitInfo? {
-            when (trait) {
-                is LengthTrait -> {
-                    return TraitInfo(
-                        { writer -> writer.rust("Self::check_length(&value)?;") },
-                        { writer ->
-                            writer.docs("Error when a string doesn't satisfy its `@length` requirements.")
-                            writer.rust("Length(usize),")
-                        },
-                        { writer ->
-                            writer.rust(
-                                """
-                                Self::Length(length) => crate::model::ValidationExceptionField {
-                                    message: format!("${trait.validationErrorMessage()}", length, &path),
-                                    path,
-                                },
-                                """.trimIndent(),
-                            )
-                        },
-                        { writer, constraintViolation -> renderLengthValidation(writer, trait, constraintViolation) },
-                    )
-                }
-
-                is PatternTrait -> {
-                    return TraitInfo(
-                        { writer -> writer.rust("Self::check_pattern(&value)?;") },
-                        { writer ->
-                            writer.docs("Error when a string doesn't satisfy its `@pattern`.")
-                            writer.rust("Pattern(&'static str),")
-                        },
-                        { writer ->
-                            writer.rust(
-                                """
-                                Self::Pattern(pattern) => crate::model::ValidationExceptionField {
-                                    message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
-                                    path
-                                },
-                                """.trimIndent(),
-                            )
-                        },
-                        { writer, constraintViolation -> renderPatternValidation(writer, trait, constraintViolation) },
-                    )
-                }
-
-                else -> {
-                    return null
-                }
-            }
-        }
-    }
-}
-
-/**
- * Renders a `check_length` function to validate the string matches the
- * required length indicated by the `@length` trait.
- */
-private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait, constraintViolation: Symbol) {
-    val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
-        "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
-    } else if (lengthTrait.min.isPresent) {
-        "${lengthTrait.min.get()} <= length"
-    } else {
-        "length <= ${lengthTrait.max.get()}"
-    }
-    writer.rust(
-        """
-        fn check_length(string: &str) -> Result<(), $constraintViolation> {
-            let length = string.chars().count();
-
-            if $condition {
-                Ok(())
-            } else {
-                Err($constraintViolation::Length(length))
-            }
-        }
-        """.trimIndent(),
-    )
-}
-
-/**
- * Renders a `check_pattern` function to validate the string matches the
- * supplied regex in the `@pattern` trait.
- */
-private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
-    // Escape `\`s to not end up with broken rust code in the presence of regexes with slashes.
-    // This turns `Regex::new("^[\S\s]+$")` into `Regex::new("^[\\S\\s]+$")`.
-    val pattern = patternTrait.pattern.toString().replace("\\", "\\\\")
-
-    writer.rustTemplate(
-        """
-        fn check_pattern(string: &str) -> Result<(), $constraintViolation> {
-            static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new("$pattern").unwrap());
-
-            if REGEX.is_match(string) {
-                Ok(())
-            } else {
-                Err($constraintViolation::Pattern("$pattern"))
-            }
-        }
-        """.trimIndent(),
-        "Regex" to ServerCargoDependency.Regex.toType(),
-        "OnceCell" to ServerCargoDependency.OnceCell.toType(),
-    )
-}
-
 private val supportedStringConstraintTraits = listOf(LengthTrait::class.java, PatternTrait::class.java)
 
 /**
@@ -313,3 +198,118 @@ class ConstrainedStringGenerator(
         }
     }
 }
+
+/**
+ * Information needed to render a constraint trait as Rust code.
+ */
+private data class TraitInfo(
+    val tryFromCheck: (writer: RustWriter) -> Unit,
+    val renderConstraintViolationVariant: (writer: RustWriter) -> Unit,
+    val asValidationExceptionField: (writer: RustWriter) -> Unit,
+    val renderValidationFunctionDefinition: (writer: RustWriter, constraintViolation: Symbol) -> Unit,
+) {
+    companion object {
+        fun fromTrait(trait: AbstractTrait): TraitInfo? {
+            when (trait) {
+                is LengthTrait -> {
+                    return TraitInfo(
+                        { writer -> writer.rust("Self::check_length(&value)?;") },
+                        { writer ->
+                            writer.docs("Error when a string doesn't satisfy its `@length` requirements.")
+                            writer.rust("Length(usize),")
+                        },
+                        { writer ->
+                            writer.rust(
+                                """
+                                Self::Length(length) => crate::model::ValidationExceptionField {
+                                    message: format!("${trait.validationErrorMessage()}", length, &path),
+                                    path,
+                                },
+                                """.trimIndent(),
+                            )
+                        },
+                        { writer, constraintViolation -> renderLengthValidation(writer, trait, constraintViolation) },
+                    )
+                }
+
+                is PatternTrait -> {
+                    return TraitInfo(
+                        { writer -> writer.rust("Self::check_pattern(&value)?;") },
+                        { writer ->
+                            writer.docs("Error when a string doesn't satisfy its `@pattern`.")
+                            writer.rust("Pattern(&'static str),")
+                        },
+                        { writer ->
+                            writer.rust(
+                                """
+                                Self::Pattern(pattern) => crate::model::ValidationExceptionField {
+                                    message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
+                                    path
+                                },
+                                """.trimIndent(),
+                            )
+                        },
+                        { writer, constraintViolation -> renderPatternValidation(writer, trait, constraintViolation) },
+                    )
+                }
+
+                else -> {
+                    return null
+                }
+            }
+        }
+    }
+}
+
+/**
+ * Renders a `check_length` function to validate the string matches the
+ * required length indicated by the `@length` trait.
+ */
+private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait, constraintViolation: Symbol) {
+    val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
+        "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
+    } else if (lengthTrait.min.isPresent) {
+        "${lengthTrait.min.get()} <= length"
+    } else {
+        "length <= ${lengthTrait.max.get()}"
+    }
+    writer.rust(
+        """
+        fn check_length(string: &str) -> Result<(), $constraintViolation> {
+            let length = string.chars().count();
+
+            if $condition {
+                Ok(())
+            } else {
+                Err($constraintViolation::Length(length))
+            }
+        }
+        """.trimIndent(),
+    )
+}
+
+/**
+ * Renders a `check_pattern` function to validate the string matches the
+ * supplied regex in the `@pattern` trait.
+ */
+private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
+    // Escape `\`s to not end up with broken rust code in the presence of regexes with slashes.
+    // This turns `Regex::new("^[\S\s]+$")` into `Regex::new("^[\\S\\s]+$")`.
+    val pattern = patternTrait.pattern.toString().replace("\\", "\\\\")
+
+    writer.rustTemplate(
+        """
+        fn check_pattern(string: &str) -> Result<(), $constraintViolation> {
+            static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new("$pattern").unwrap());
+
+            if REGEX.is_match(string) {
+                Ok(())
+            } else {
+                Err($constraintViolation::Pattern("$pattern"))
+            }
+        }
+        """.trimIndent(),
+        "Regex" to ServerCargoDependency.Regex.toType(),
+        "OnceCell" to ServerCargoDependency.OnceCell.toType(),
+    )
+}

From d26a87715092bae0fe9a433642d438b4fd0b307e Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 13:36:07 +0000
Subject: [PATCH 26/59] Extract branches in `TraitInfo.fromTrait` into separate
 functions

---
 .../generators/ConstrainedStringGenerator.kt  | 84 ++++++++++---------
 1 file changed, 46 insertions(+), 38 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 48f551f60d..025ac7bd31 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -210,54 +210,62 @@ private data class TraitInfo(
 ) {
     companion object {
         fun fromTrait(trait: AbstractTrait): TraitInfo? {
-            when (trait) {
+            return when (trait) {
                 is LengthTrait -> {
-                    return TraitInfo(
-                        { writer -> writer.rust("Self::check_length(&value)?;") },
-                        { writer ->
-                            writer.docs("Error when a string doesn't satisfy its `@length` requirements.")
-                            writer.rust("Length(usize),")
-                        },
-                        { writer ->
-                            writer.rust(
-                                """
-                                Self::Length(length) => crate::model::ValidationExceptionField {
-                                    message: format!("${trait.validationErrorMessage()}", length, &path),
-                                    path,
-                                },
-                                """.trimIndent(),
-                            )
-                        },
-                        { writer, constraintViolation -> renderLengthValidation(writer, trait, constraintViolation) },
-                    )
+                    this.fromLengthTrait(trait)
                 }
 
                 is PatternTrait -> {
-                    return TraitInfo(
-                        { writer -> writer.rust("Self::check_pattern(&value)?;") },
-                        { writer ->
-                            writer.docs("Error when a string doesn't satisfy its `@pattern`.")
-                            writer.rust("Pattern(&'static str),")
-                        },
-                        { writer ->
-                            writer.rust(
-                                """
-                                Self::Pattern(pattern) => crate::model::ValidationExceptionField {
-                                    message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
-                                    path
-                                },
-                                """.trimIndent(),
-                            )
-                        },
-                        { writer, constraintViolation -> renderPatternValidation(writer, trait, constraintViolation) },
-                    )
+                    this.fromPatternTrait(trait)
                 }
 
                 else -> {
-                    return null
+                    null
                 }
             }
         }
+
+        private fun fromLengthTrait(lengthTrait: LengthTrait): TraitInfo {
+            return TraitInfo(
+                { writer -> writer.rust("Self::check_length(&value)?;") },
+                { writer ->
+                    writer.docs("Error when a string doesn't satisfy its `@length` requirements.")
+                    writer.rust("Length(usize),")
+                },
+                { writer ->
+                    writer.rust(
+                        """
+                        Self::Length(length) => crate::model::ValidationExceptionField {
+                            message: format!("${lengthTrait.validationErrorMessage()}", length, &path),
+                            path,
+                        },
+                        """.trimIndent(),
+                    )
+                },
+                { writer, constraintViolation -> renderLengthValidation(writer, lengthTrait, constraintViolation) },
+            )
+        }
+
+        private fun fromPatternTrait(patternTrait: PatternTrait): TraitInfo {
+            return TraitInfo(
+                { writer -> writer.rust("Self::check_pattern(&value)?;") },
+                { writer ->
+                    writer.docs("Error when a string doesn't satisfy its `@pattern`.")
+                    writer.rust("Pattern(&'static str),")
+                },
+                { writer ->
+                    writer.rust(
+                        """
+                        Self::Pattern(pattern) => crate::model::ValidationExceptionField {
+                            message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
+                            path
+                        },
+                        """.trimIndent(),
+                    )
+                },
+                { writer, constraintViolation -> renderPatternValidation(writer, patternTrait, constraintViolation) },
+            )
+        }
     }
 }
 

From 0d7bbee01c5814afffa14273f6115f0c179513b9 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 13:48:17 +0000
Subject: [PATCH 27/59] Add `PatternTrait.validationErrorMessage`

---
 .../smithy/PatternTraitValidationErrorMessage.kt | 16 ++++++++++++++++
 .../generators/ConstrainedStringGenerator.kt     |  7 +++----
 2 files changed, 19 insertions(+), 4 deletions(-)
 create mode 100644 codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
new file mode 100644
index 0000000000..bd345e7e8a
--- /dev/null
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
@@ -0,0 +1,16 @@
+package software.amazon.smithy.rust.codegen.server.smithy
+
+import software.amazon.smithy.model.traits.PatternTrait
+
+@Suppress("UnusedReceiverParameter")
+fun PatternTrait.validationErrorMessage(): String {
+    return "Value at '{}' failed to satisfy constraint: Member must satisfy regex '{}'."
+}
+
+/**
+ * Escape `\`s to not end up with broken rust code in the presence of regexes with slashes.
+ * This turns `Regex::new("^[\S\s]+$")` into `Regex::new("^[\\S\\s]+$")`.
+ */
+fun PatternTrait.escapedPattern(): String {
+    return this.pattern.toString().replace("\\", "\\\\")
+}
diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 025ac7bd31..ad13718098 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -30,6 +30,7 @@ import software.amazon.smithy.rust.codegen.core.util.redactIfNecessary
 import software.amazon.smithy.rust.codegen.server.smithy.PubCrateConstraintViolationSymbolProvider
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCargoDependency
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
+import software.amazon.smithy.rust.codegen.server.smithy.escapedPattern
 import software.amazon.smithy.rust.codegen.server.smithy.traits.isReachableFromOperationInput
 import software.amazon.smithy.rust.codegen.server.smithy.validationErrorMessage
 
@@ -257,7 +258,7 @@ private data class TraitInfo(
                     writer.rust(
                         """
                         Self::Pattern(pattern) => crate::model::ValidationExceptionField {
-                            message: format!("String at path {} failed to satisfy pattern {}", &path, pattern),
+                            message: format!("${patternTrait.validationErrorMessage()}", &path, pattern),
                             path
                         },
                         """.trimIndent(),
@@ -301,9 +302,7 @@ private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait,
  * supplied regex in the `@pattern` trait.
  */
 private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
-    // Escape `\`s to not end up with broken rust code in the presence of regexes with slashes.
-    // This turns `Regex::new("^[\S\s]+$")` into `Regex::new("^[\\S\\s]+$")`.
-    val pattern = patternTrait.pattern.toString().replace("\\", "\\\\")
+    val pattern = patternTrait.escapedPattern()
 
     writer.rustTemplate(
         """

From 85ddc4c23c968b62106d78c4e938c36491d26468 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 13:52:35 +0000
Subject: [PATCH 28/59] Add more tests for `@pattern`

---
 .../server/smithy/PatternTraitValidationErrorMessage.kt  | 5 +++++
 .../smithy/generators/ConstrainedStringGeneratorTest.kt  | 9 ++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
index bd345e7e8a..6e4cba3fe9 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
@@ -1,3 +1,8 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 package software.amazon.smithy.rust.codegen.server.smithy
 
 import software.amazon.smithy.model.traits.PatternTrait
diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
index 3ba301937c..21b0bf5c5f 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
@@ -45,8 +45,15 @@ class ConstrainedStringGeneratorTest {
                 "👍👍👍", // These three emojis are three Unicode scalar values.
                 "👍👍👍👍",
             ),
-            // Need to fix the setup to be able to add `@pattern` tests.
             Triple("@pattern(\"^[a-z]+$\")", "valid", "123 invalid"),
+            Triple(
+                """
+                @length(min: 3, max: 10)
+                @pattern("^a string$)
+                """.trimIndent(),
+                "a string", "an invalid string",
+            ),
+            Triple("@pattern(\"123\")", "some pattern 123 in the middle", "no pattern at all"),
         ).map {
             TestCase(
                 """

From a6ad449846b92488f9ab5024643c24950f9f3983 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 13:55:46 +0000
Subject: [PATCH 29/59] Add entry to `CHANGELOG.next.toml`

---
 CHANGELOG.next.toml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.next.toml b/CHANGELOG.next.toml
index ccd59ef313..a628b7a30f 100644
--- a/CHANGELOG.next.toml
+++ b/CHANGELOG.next.toml
@@ -221,12 +221,13 @@ message = """
 
 * The `length` trait on `string` shapes.
 * The `length` trait on `map` shapes.
+* The `pattern` trait on `string` shapes.
 
 Upon receiving a request that violates the modeled constraints, the server SDK will reject it with a message indicating why.
 
 Unsupported (constraint trait, target shape) combinations will now fail at code generation time, whereas previously they were just ignored. This is a breaking change to raise awareness in service owners of their server SDKs behaving differently than what was modeled. To continue generating a server SDK with unsupported constraint traits, set `codegenConfig.ignoreUnsupportedConstraints` to `true` in your `smithy-build.json`.
 """
-references = ["smithy-rs#1199", "smithy-rs#1342", "smithy-rs#1401"]
+references = ["smithy-rs#1199", "smithy-rs#1342", "smithy-rs#1401", "smithy-rs#1998"]
 meta = { "breaking" = true, "tada" = true, "bug" = false, "target" = "server" }
 author = "david-perez"
 

From 8ade3a15ad6b548630599c6f43ad726d99c1078d Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Fri, 18 Nov 2022 14:20:47 +0000
Subject: [PATCH 30/59] Fix a `@length` + `@pattern` test case

---
 .../smithy/generators/ConstrainedStringGeneratorTest.kt     | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
index 21b0bf5c5f..77427b2024 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
@@ -30,7 +30,7 @@ class ConstrainedStringGeneratorTest {
     data class TestCase(val model: Model, val validString: String, val invalidString: String)
 
     class ConstrainedStringGeneratorTestProvider : ArgumentsProvider {
-        private val lengthTestCases = listOf(
+        private val testCases = listOf(
             // Min and max.
             Triple("@length(min: 11, max: 12)", "validString", "invalidString"),
             // Min equal to max.
@@ -49,7 +49,7 @@ class ConstrainedStringGeneratorTest {
             Triple(
                 """
                 @length(min: 3, max: 10)
-                @pattern("^a string$)
+                @pattern("^a string$")
                 """.trimIndent(),
                 "a string", "an invalid string",
             ),
@@ -68,7 +68,7 @@ class ConstrainedStringGeneratorTest {
         }
 
         override fun provideArguments(context: ExtensionContext?): Stream<out Arguments> =
-            lengthTestCases.map { Arguments.of(it) }.stream()
+            testCases.map { Arguments.of(it) }.stream()
     }
 
     @ParameterizedTest

From 961e3af17a92d2164ad6e337895c42fa9ec25ec2 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 09:45:39 +0000
Subject: [PATCH 31/59] Remove unused binding in
 `ConstrainedStringGeneratorTest`

---
 .../smithy/generators/ConstrainedStringGeneratorTest.kt       | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
index 77427b2024..ddf9a53d07 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGeneratorTest.kt
@@ -14,7 +14,6 @@ import org.junit.jupiter.params.provider.ArgumentsProvider
 import org.junit.jupiter.params.provider.ArgumentsSource
 import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.shapes.StringShape
-import software.amazon.smithy.model.traits.PatternTrait
 import software.amazon.smithy.rust.codegen.core.rustlang.RustWriter
 import software.amazon.smithy.rust.codegen.core.smithy.ModelsModule
 import software.amazon.smithy.rust.codegen.core.testutil.TestWorkspace
@@ -26,7 +25,6 @@ import software.amazon.smithy.rust.codegen.server.smithy.testutil.serverTestCode
 import java.util.stream.Stream
 
 class ConstrainedStringGeneratorTest {
-    val a = PatternTrait("something")
     data class TestCase(val model: Model, val validString: String, val invalidString: String)
 
     class ConstrainedStringGeneratorTestProvider : ArgumentsProvider {
@@ -50,7 +48,7 @@ class ConstrainedStringGeneratorTest {
                 """
                 @length(min: 3, max: 10)
                 @pattern("^a string$")
-                """.trimIndent(),
+                """,
                 "a string", "an invalid string",
             ),
             Triple("@pattern(\"123\")", "some pattern 123 in the middle", "no pattern at all"),

From 8a1f73f18e7a748f6363ac5b36d06791b2dcae21 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 09:46:02 +0000
Subject: [PATCH 32/59] Remove calls to `trimIndent`

---
 .../smithy/generators/ConstrainedStringGenerator.kt  | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index ad13718098..bdb20347a0 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -127,7 +127,7 @@ class ConstrainedStringGenerator(
                 pub fn into_inner(self) -> $inner {
                     self.0
                 }
-                """.trimIndent(),
+                """,
             )
         }
 
@@ -176,7 +176,7 @@ class ConstrainedStringGenerator(
             """
             ##[derive(Debug, PartialEq)]
             pub enum ${constraintViolation.name}
-            """.trimIndent(),
+            """,
         ) {
             for (traitInfo in constraintsInfo) {
                 traitInfo.renderConstraintViolationVariant(this)
@@ -240,7 +240,7 @@ private data class TraitInfo(
                             message: format!("${lengthTrait.validationErrorMessage()}", length, &path),
                             path,
                         },
-                        """.trimIndent(),
+                        """,
                     )
                 },
                 { writer, constraintViolation -> renderLengthValidation(writer, lengthTrait, constraintViolation) },
@@ -261,7 +261,7 @@ private data class TraitInfo(
                             message: format!("${patternTrait.validationErrorMessage()}", &path, pattern),
                             path
                         },
-                        """.trimIndent(),
+                        """,
                     )
                 },
                 { writer, constraintViolation -> renderPatternValidation(writer, patternTrait, constraintViolation) },
@@ -293,7 +293,7 @@ private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait,
                 Err($constraintViolation::Length(length))
             }
         }
-        """.trimIndent(),
+        """,
     )
 }
 
@@ -315,7 +315,7 @@ private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTra
                 Err($constraintViolation::Pattern("$pattern"))
             }
         }
-        """.trimIndent(),
+        """,
         "Regex" to ServerCargoDependency.Regex.toType(),
         "OnceCell" to ServerCargoDependency.OnceCell.toType(),
     )

From 1f02303310b8b0f6864238227145c89aa748c460 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 09:51:43 +0000
Subject: [PATCH 33/59] Use raw Rust strings instead of `escapedPattern`

---
 .../server/smithy/PatternTraitValidationErrorMessage.kt   | 8 --------
 .../smithy/generators/ConstrainedStringGenerator.kt       | 7 +++----
 2 files changed, 3 insertions(+), 12 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
index 6e4cba3fe9..bb6bcb8981 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
@@ -11,11 +11,3 @@ import software.amazon.smithy.model.traits.PatternTrait
 fun PatternTrait.validationErrorMessage(): String {
     return "Value at '{}' failed to satisfy constraint: Member must satisfy regex '{}'."
 }
-
-/**
- * Escape `\`s to not end up with broken rust code in the presence of regexes with slashes.
- * This turns `Regex::new("^[\S\s]+$")` into `Regex::new("^[\\S\\s]+$")`.
- */
-fun PatternTrait.escapedPattern(): String {
-    return this.pattern.toString().replace("\\", "\\\\")
-}
diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index bdb20347a0..ef9e0daa9a 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -30,7 +30,6 @@ import software.amazon.smithy.rust.codegen.core.util.redactIfNecessary
 import software.amazon.smithy.rust.codegen.server.smithy.PubCrateConstraintViolationSymbolProvider
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCargoDependency
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
-import software.amazon.smithy.rust.codegen.server.smithy.escapedPattern
 import software.amazon.smithy.rust.codegen.server.smithy.traits.isReachableFromOperationInput
 import software.amazon.smithy.rust.codegen.server.smithy.validationErrorMessage
 
@@ -302,17 +301,17 @@ private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait,
  * supplied regex in the `@pattern` trait.
  */
 private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
-    val pattern = patternTrait.escapedPattern()
+    val pattern = patternTrait.pattern
 
     writer.rustTemplate(
         """
         fn check_pattern(string: &str) -> Result<(), $constraintViolation> {
-            static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new("$pattern").unwrap());
+            static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new(r#"$pattern"#).unwrap());
 
             if REGEX.is_match(string) {
                 Ok(())
             } else {
-                Err($constraintViolation::Pattern("$pattern"))
+                Err($constraintViolation::Pattern(r#"$pattern"#))
             }
         }
         """,

From dcd2528fe938c7ddcc419793c57940030952b0d8 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 09:55:06 +0000
Subject: [PATCH 34/59] Require `regex 1.5.5` instead of `1.7.0`

---
 .../smithy/rust/codegen/server/smithy/ServerCargoDependency.kt  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCargoDependency.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCargoDependency.kt
index ef2e930dfd..a5735b81d8 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCargoDependency.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCargoDependency.kt
@@ -25,7 +25,7 @@ object ServerCargoDependency {
     val PinProjectLite: CargoDependency = CargoDependency("pin-project-lite", CratesIo("0.2"))
     val Tower: CargoDependency = CargoDependency("tower", CratesIo("0.4"))
     val TokioDev: CargoDependency = CargoDependency("tokio", CratesIo("1.8.4"), scope = DependencyScope.Dev)
-    val Regex: CargoDependency = CargoDependency("regex", CratesIo("1.7.0"))
+    val Regex: CargoDependency = CargoDependency("regex", CratesIo("1.5.5"))
 
     fun SmithyHttpServer(runtimeConfig: RuntimeConfig) = runtimeConfig.runtimeCrate("http-server")
 }

From d90f44797264b33168d464d9da4bac9f0e5c3d47 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 10:37:40 +0000
Subject: [PATCH 35/59] Use `Writable`s in `TraitInfo`

---
 .../generators/ConstrainedStringGenerator.kt  | 48 ++++++++++---------
 1 file changed, 26 insertions(+), 22 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index ef9e0daa9a..7ccf55f683 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -16,6 +16,7 @@ import software.amazon.smithy.rust.codegen.core.rustlang.RustModule
 import software.amazon.smithy.rust.codegen.core.rustlang.RustType
 import software.amazon.smithy.rust.codegen.core.rustlang.RustWriter
 import software.amazon.smithy.rust.codegen.core.rustlang.Visibility
+import software.amazon.smithy.rust.codegen.core.rustlang.Writable
 import software.amazon.smithy.rust.codegen.core.rustlang.docs
 import software.amazon.smithy.rust.codegen.core.rustlang.documentShape
 import software.amazon.smithy.rust.codegen.core.rustlang.render
@@ -64,7 +65,7 @@ class ConstrainedStringGenerator(
     private fun renderTryFrom(inner: String, name: String, constraintViolation: Symbol) {
         writer.rustBlock("impl $name") {
             for (traitInfo in constraintsInfo) {
-                traitInfo.renderValidationFunctionDefinition(writer, constraintViolation)
+                rustTemplate("#ValidationFunction:W", "ValidationFunction" to traitInfo.validationFunctionDefinition(constraintViolation))
             }
         }
 
@@ -77,7 +78,7 @@ class ConstrainedStringGenerator(
                 """,
             ) {
                 for (traitInfo in constraintsInfo) {
-                    traitInfo.tryFromCheck(writer)
+                    rustTemplate("#TryFromCheck:W", "TryFromCheck" to traitInfo.tryFromCheck)
                 }
                 rust("Ok(Self(value))")
             }
@@ -178,7 +179,10 @@ class ConstrainedStringGenerator(
             """,
         ) {
             for (traitInfo in constraintsInfo) {
-                traitInfo.renderConstraintViolationVariant(this)
+                rustTemplate(
+                    "#ConstraintViolationVariant",
+                    "ConstraintViolationVariant:W" to traitInfo.constraintViolationVariant,
+                )
             }
         }
 
@@ -190,7 +194,7 @@ class ConstrainedStringGenerator(
                 ) {
                     rustBlock("match self") {
                         for (traitInfo in constraintsInfo) {
-                            traitInfo.asValidationExceptionField(this)
+                            rustTemplate("#ValidationExceptionField:W", "ValidationExceptionField" to traitInfo.asValidationExceptionField)
                         }
                     }
                 }
@@ -203,10 +207,10 @@ class ConstrainedStringGenerator(
  * Information needed to render a constraint trait as Rust code.
  */
 private data class TraitInfo(
-    val tryFromCheck: (writer: RustWriter) -> Unit,
-    val renderConstraintViolationVariant: (writer: RustWriter) -> Unit,
-    val asValidationExceptionField: (writer: RustWriter) -> Unit,
-    val renderValidationFunctionDefinition: (writer: RustWriter, constraintViolation: Symbol) -> Unit,
+    val tryFromCheck: Writable,
+    val constraintViolationVariant: Writable,
+    val asValidationExceptionField: Writable,
+    val validationFunctionDefinition: (constraintViolation: Symbol) -> Writable,
 ) {
     companion object {
         fun fromTrait(trait: AbstractTrait): TraitInfo? {
@@ -227,13 +231,13 @@ private data class TraitInfo(
 
         private fun fromLengthTrait(lengthTrait: LengthTrait): TraitInfo {
             return TraitInfo(
-                { writer -> writer.rust("Self::check_length(&value)?;") },
-                { writer ->
-                    writer.docs("Error when a string doesn't satisfy its `@length` requirements.")
-                    writer.rust("Length(usize),")
+                { rust("Self::check_length(&value)?;") },
+                {
+                    docs("Error when a string doesn't satisfy its `@length` requirements.")
+                    rust("Length(usize),")
                 },
-                { writer ->
-                    writer.rust(
+                {
+                    rust(
                         """
                         Self::Length(length) => crate::model::ValidationExceptionField {
                             message: format!("${lengthTrait.validationErrorMessage()}", length, &path),
@@ -242,19 +246,19 @@ private data class TraitInfo(
                         """,
                     )
                 },
-                { writer, constraintViolation -> renderLengthValidation(writer, lengthTrait, constraintViolation) },
+                { constraintViolation -> { renderLengthValidation(this, lengthTrait, constraintViolation) } },
             )
         }
 
         private fun fromPatternTrait(patternTrait: PatternTrait): TraitInfo {
             return TraitInfo(
-                { writer -> writer.rust("Self::check_pattern(&value)?;") },
-                { writer ->
-                    writer.docs("Error when a string doesn't satisfy its `@pattern`.")
-                    writer.rust("Pattern(&'static str),")
+                { rust("Self::check_pattern(&value)?;") },
+                {
+                    docs("Error when a string doesn't satisfy its `@pattern`.")
+                    rust("Pattern(&'static str),")
                 },
-                { writer ->
-                    writer.rust(
+                {
+                    rust(
                         """
                         Self::Pattern(pattern) => crate::model::ValidationExceptionField {
                             message: format!("${patternTrait.validationErrorMessage()}", &path, pattern),
@@ -263,7 +267,7 @@ private data class TraitInfo(
                         """,
                     )
                 },
-                { writer, constraintViolation -> renderPatternValidation(writer, patternTrait, constraintViolation) },
+                { constraintViolation -> { renderPatternValidation(this, patternTrait, constraintViolation) } },
             )
         }
     }

From 78d65125698bcaa60382bfd893bd3618019f6b9c Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 11:04:10 +0000
Subject: [PATCH 36/59] Use single `rust` call for `impl $name` block

---
 .../smithy/generators/ConstrainedStringGenerator.kt   | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 7ccf55f683..0cde3da6e0 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -110,9 +110,9 @@ class ConstrainedStringGenerator(
         if (constrainedTypeVisibility == Visibility.PUBCRATE) {
             Attribute.AllowUnused.render(writer)
         }
-        writer.rustBlockTemplate("impl $name") {
-            rust(
-                """
+        writer.rust(
+            """
+            impl $name {
                 /// Extracts a string slice containing the entire underlying `String`.
                 pub fn as_str(&self) -> &str {
                     &self.0
@@ -127,9 +127,8 @@ class ConstrainedStringGenerator(
                 pub fn into_inner(self) -> $inner {
                     self.0
                 }
-                """,
-            )
-        }
+            }""",
+        )
 
         renderTryFrom(inner, name, constraintViolation)
 

From 4234b6d795536acdc8cd8956d85c2da7250f297d Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 11:49:34 +0000
Subject: [PATCH 37/59] Move `supportedStringConstraintTraits` to
 `Constraints.kt`

---
 .../smithy/rust/codegen/server/smithy/Constraints.kt       | 6 ++++--
 .../server/smithy/generators/ConstrainedStringGenerator.kt | 7 +++----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt
index c8f8684f18..35211f01fd 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt
@@ -21,6 +21,7 @@ import software.amazon.smithy.model.traits.LengthTrait
 import software.amazon.smithy.model.traits.PatternTrait
 import software.amazon.smithy.model.traits.RangeTrait
 import software.amazon.smithy.model.traits.RequiredTrait
+import software.amazon.smithy.model.traits.Trait
 import software.amazon.smithy.model.traits.UniqueItemsTrait
 import software.amazon.smithy.rust.codegen.core.smithy.isOptional
 import software.amazon.smithy.rust.codegen.core.util.UNREACHABLE
@@ -42,6 +43,8 @@ fun Shape.hasConstraintTrait() =
         hasTrait<RangeTrait>() ||
         hasTrait<RequiredTrait>()
 
+val supportedStringConstraintTraits: List<Class<out Trait>> = listOf(LengthTrait::class.java, PatternTrait::class.java)
+
 /**
  * We say a shape is _directly_ constrained if:
  *
@@ -66,8 +69,7 @@ fun Shape.isDirectlyConstrained(symbolProvider: SymbolProvider): Boolean = when
         this.members().map { symbolProvider.toSymbol(it) }.any { !it.isOptional() }
     }
     is MapShape -> this.hasTrait<LengthTrait>()
-    is StringShape ->
-        this.hasTrait<EnumTrait>() || this.hasTrait<LengthTrait>() || this.hasTrait<PatternTrait>()
+    is StringShape -> this.hasTrait<EnumTrait>() || supportedStringConstraintTraits.any { this.hasTrait(it) }
     else -> false
 }
 
diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 0cde3da6e0..e5b242b4ad 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -7,9 +7,9 @@ package software.amazon.smithy.rust.codegen.server.smithy.generators
 
 import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.model.shapes.StringShape
-import software.amazon.smithy.model.traits.AbstractTrait
 import software.amazon.smithy.model.traits.LengthTrait
 import software.amazon.smithy.model.traits.PatternTrait
+import software.amazon.smithy.model.traits.Trait
 import software.amazon.smithy.rust.codegen.core.rustlang.Attribute
 import software.amazon.smithy.rust.codegen.core.rustlang.RustMetadata
 import software.amazon.smithy.rust.codegen.core.rustlang.RustModule
@@ -31,11 +31,10 @@ import software.amazon.smithy.rust.codegen.core.util.redactIfNecessary
 import software.amazon.smithy.rust.codegen.server.smithy.PubCrateConstraintViolationSymbolProvider
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCargoDependency
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
+import software.amazon.smithy.rust.codegen.server.smithy.supportedStringConstraintTraits
 import software.amazon.smithy.rust.codegen.server.smithy.traits.isReachableFromOperationInput
 import software.amazon.smithy.rust.codegen.server.smithy.validationErrorMessage
 
-private val supportedStringConstraintTraits = listOf(LengthTrait::class.java, PatternTrait::class.java)
-
 /**
  * [ConstrainedStringGenerator] generates a wrapper tuple newtype holding a constrained `String`.
  * This type can be built from unconstrained values, yielding a `ConstraintViolation` when the input does not satisfy
@@ -212,7 +211,7 @@ private data class TraitInfo(
     val validationFunctionDefinition: (constraintViolation: Symbol) -> Writable,
 ) {
     companion object {
-        fun fromTrait(trait: AbstractTrait): TraitInfo? {
+        fun fromTrait(trait: Trait): TraitInfo? {
             return when (trait) {
                 is LengthTrait -> {
                     this.fromLengthTrait(trait)

From abaf910583675066ab69349b55a3034170a77a08 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 12:03:38 +0000
Subject: [PATCH 38/59] Fix error message mentioning wrong
 `ignoreUnsupportedConstraintTraits` key

---
 .../codegen/server/smithy/ValidateUnsupportedConstraints.kt     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraints.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraints.kt
index cdc745a8e6..014e60ed5d 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraints.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraints.kt
@@ -41,7 +41,7 @@ private sealed class UnsupportedConstraintMessageKind {
             This is not supported in the smithy-rs server SDK.
             ${ if (willSupport) "It will be supported in the future." else "" }
             See the tracking issue ($trackingIssue).
-            If you want to go ahead and generate the server SDK ignoring unsupported constraint traits, set the key `ignoreUnsupportedConstraintTraits`
+            If you want to go ahead and generate the server SDK ignoring unsupported constraint traits, set the key `ignoreUnsupportedConstraints`
             inside the `runtimeConfig.codegenConfig` JSON object in your `smithy-build.json` to `true`.
             """.trimIndent().replace("\n", " ")
 

From 46b126b8c5480cbce1ceba987f29c0d7896a7fb6 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 13:37:32 +0000
Subject: [PATCH 39/59] Fix usage of `:W` in `rustTemplate` and raw Rust
 strings

---
 .../generators/ConstrainedStringGenerator.kt       | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index e5b242b4ad..b97970d0fd 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -64,7 +64,7 @@ class ConstrainedStringGenerator(
     private fun renderTryFrom(inner: String, name: String, constraintViolation: Symbol) {
         writer.rustBlock("impl $name") {
             for (traitInfo in constraintsInfo) {
-                rustTemplate("#ValidationFunction:W", "ValidationFunction" to traitInfo.validationFunctionDefinition(constraintViolation))
+                rustTemplate("#{ValidationFunction:W}", "ValidationFunction" to traitInfo.validationFunctionDefinition(constraintViolation))
             }
         }
 
@@ -77,7 +77,7 @@ class ConstrainedStringGenerator(
                 """,
             ) {
                 for (traitInfo in constraintsInfo) {
-                    rustTemplate("#TryFromCheck:W", "TryFromCheck" to traitInfo.tryFromCheck)
+                    rustTemplate("#{TryFromCheck:W}", "TryFromCheck" to traitInfo.tryFromCheck)
                 }
                 rust("Ok(Self(value))")
             }
@@ -178,8 +178,8 @@ class ConstrainedStringGenerator(
         ) {
             for (traitInfo in constraintsInfo) {
                 rustTemplate(
-                    "#ConstraintViolationVariant",
-                    "ConstraintViolationVariant:W" to traitInfo.constraintViolationVariant,
+                    "#{ConstraintViolationVariant:W}",
+                    "ConstraintViolationVariant" to traitInfo.constraintViolationVariant,
                 )
             }
         }
@@ -192,7 +192,7 @@ class ConstrainedStringGenerator(
                 ) {
                     rustBlock("match self") {
                         for (traitInfo in constraintsInfo) {
-                            rustTemplate("#ValidationExceptionField:W", "ValidationExceptionField" to traitInfo.asValidationExceptionField)
+                            rustTemplate("#{ValidationExceptionField:W}", "ValidationExceptionField" to traitInfo.asValidationExceptionField)
                         }
                     }
                 }
@@ -308,12 +308,12 @@ private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTra
     writer.rustTemplate(
         """
         fn check_pattern(string: &str) -> Result<(), $constraintViolation> {
-            static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new(r#"$pattern"#).unwrap());
+            static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new(r##"$pattern"##).unwrap());
 
             if REGEX.is_match(string) {
                 Ok(())
             } else {
-                Err($constraintViolation::Pattern(r#"$pattern"#))
+                Err($constraintViolation::Pattern(r##"$pattern"##))
             }
         }
         """,

From d5511680aa165d6f3422e0cf46fdd0c28b41e1ac Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 13:42:36 +0000
Subject: [PATCH 40/59] Use shorthand form for
 `PatternTrait.validationErrorMessage`

---
 .../server/smithy/PatternTraitValidationErrorMessage.kt      | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
index bb6bcb8981..9bace222dd 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
@@ -8,6 +8,5 @@ package software.amazon.smithy.rust.codegen.server.smithy
 import software.amazon.smithy.model.traits.PatternTrait
 
 @Suppress("UnusedReceiverParameter")
-fun PatternTrait.validationErrorMessage(): String {
-    return "Value at '{}' failed to satisfy constraint: Member must satisfy regex '{}'."
-}
+fun PatternTrait.validationErrorMessage(): String =
+    "Value at '{}' failed to satisfy constraint: Member must satisfy regex '{}'."

From 76e5984dea2fe32a689c7f3caa2779bcaa9648b2 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 13:54:20 +0000
Subject: [PATCH 41/59] Fix protocol tests by adjusting the validation message

---
 .../PatternTraitValidationErrorMessage.kt     |  2 +-
 .../generators/ConstrainedStringGenerator.kt  | 19 +++++++++++--------
 .../protocol/ServerProtocolTestGenerator.kt   | 10 ----------
 3 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
index 9bace222dd..8bb3cb648e 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/PatternTraitValidationErrorMessage.kt
@@ -9,4 +9,4 @@ import software.amazon.smithy.model.traits.PatternTrait
 
 @Suppress("UnusedReceiverParameter")
 fun PatternTrait.validationErrorMessage(): String =
-    "Value at '{}' failed to satisfy constraint: Member must satisfy regex '{}'."
+    "Value {} at '{}' failed to satisfy constraint: Member must satisfy regular expression pattern: {}"
diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index b97970d0fd..9b8a8ec911 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -249,17 +249,20 @@ private data class TraitInfo(
         }
 
         private fun fromPatternTrait(patternTrait: PatternTrait): TraitInfo {
+            val pattern = patternTrait.pattern
+
             return TraitInfo(
-                { rust("Self::check_pattern(&value)?;") },
+                { rust("let value = Self::check_pattern(value)?;") },
                 {
                     docs("Error when a string doesn't satisfy its `@pattern`.")
-                    rust("Pattern(&'static str),")
+                    docs("Contains the String that failed the pattern.")
+                    rust("Pattern(String),")
                 },
                 {
                     rust(
                         """
-                        Self::Pattern(pattern) => crate::model::ValidationExceptionField {
-                            message: format!("${patternTrait.validationErrorMessage()}", &path, pattern),
+                        Self::Pattern(string) => crate::model::ValidationExceptionField {
+                            message: format!("${patternTrait.validationErrorMessage()}", &string, &path, r##"$pattern"##),
                             path
                         },
                         """,
@@ -307,13 +310,13 @@ private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTra
 
     writer.rustTemplate(
         """
-        fn check_pattern(string: &str) -> Result<(), $constraintViolation> {
+        fn check_pattern(string: String) -> Result<String, $constraintViolation> {
             static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new(r##"$pattern"##).unwrap());
 
-            if REGEX.is_match(string) {
-                Ok(())
+            if REGEX.is_match(&string) {
+                Ok(string)
             } else {
-                Err($constraintViolation::Pattern(r##"$pattern"##))
+                Err($constraintViolation::Pattern(string))
             }
         }
         """,
diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
index cf981edb73..2d61e8011f 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
@@ -969,17 +969,7 @@ class ServerProtocolTestGenerator(
             FailingTest(RestJsonValidation, "RestJsonMalformedPatternStringOverride_case1", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedPatternUnionOverride_case0", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedPatternUnionOverride_case1", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternList_case0", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternList_case1", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternMapKey_case0", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternMapKey_case1", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternMapValue_case0", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternMapValue_case1", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedPatternReDOSString", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternString_case0", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternString_case1", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternUnion_case0", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternUnion_case1", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedRangeByteOverride_case0", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedRangeByteOverride_case1", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedRangeFloatOverride_case0", TestType.MalformedRequest),

From 227ddaf74aa23ef9c95eabcf3bcc4c5388ba3101 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 15:48:13 +0000
Subject: [PATCH 42/59] Add uses of `@pattern` in `constraints.smithy` model

---
 .../common-test-models/constraints.smithy     | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/codegen-core/common-test-models/constraints.smithy b/codegen-core/common-test-models/constraints.smithy
index d43ea8b7b2..98486c989a 100644
--- a/codegen-core/common-test-models/constraints.smithy
+++ b/codegen-core/common-test-models/constraints.smithy
@@ -23,6 +23,10 @@ service ConstraintsService {
         QueryParamsTargetingMapOfListOfLengthStringOperation,
         QueryParamsTargetingMapOfSetOfLengthStringOperation,
         QueryParamsTargetingMapOfListOfEnumStringOperation,
+
+        QueryParamsTargetingMapOfPatternStringOperation,
+        QueryParamsTargetingMapOfLengthPatternStringOperation,
+
         HttpPrefixHeadersTargetingLengthMapOperation,
         // TODO(https://github.com/awslabs/smithy-rs/issues/1431)
         // HttpPrefixHeadersTargetingMapOfEnumStringOperation,
@@ -97,6 +101,20 @@ operation QueryParamsTargetingMapOfListOfEnumStringOperation {
     errors: [ValidationException]
 }
 
+@http(uri: "/query-params-targeting-map-of-pattern-string", method: "POST")
+operation QueryParamsTargetingMapOfPatternStringOperation {
+    input: QueryParamsTargetingMapOfPatternStringOperationInputOutput,
+    output: QueryParamsTargetingMapOfPatternStringOperationInputOutput,
+    errors: [ValidationException]
+}
+
+@http(uri: "/query-params-targeting-map-of-length-pattern-string", method: "POST")
+operation QueryParamsTargetingMapOfLengthPatternStringOperation {
+    input: QueryParamsTargetingMapOfLengthPatternStringOperationInputOutput,
+    output: QueryParamsTargetingMapOfLengthPatternStringOperationInputOutput,
+    errors: [ValidationException],
+}
+
 @http(uri: "/http-prefix-headers-targeting-length-map-operation", method: "POST")
 operation HttpPrefixHeadersTargetingLengthMapOperation {
     input: HttpPrefixHeadersTargetingLengthMapOperationInputOutput,
@@ -183,6 +201,16 @@ structure ConstrainedHttpBoundShapesOperationInputOutput {
     enumStringListQuery: ListOfEnumString,
 }
 
+structure QueryParamsTargetingMapOfPatternStringOperationInputOutput {
+    @httpQueryParams
+    mapOfPatternString: MapOfPatternString
+}
+
+structure QueryParamsTargetingMapOfLengthPatternStringOperationInputOutput {
+    @httpQueryParams
+    mapOfLengthPatternString: MapOfLengthPatternString,
+}
+
 structure HttpPrefixHeadersTargetingLengthMapOperationInputOutput {
     @httpPrefixHeaders("X-Prefix-Headers-LengthMap-")
     lengthMap: ConBMap,
@@ -335,6 +363,13 @@ string MaxLengthString
 @length(min: 69, max: 69)
 string FixedLengthString
 
+@pattern("[a-d]{5}")
+string PatternString
+
+@pattern("[a-f0-5]*")
+@length(min:5, max: 10)
+string LengthPatternString
+
 @mediaType("video/quicktime")
 @length(min: 1, max: 69)
 string MediaTypeLengthString
@@ -428,6 +463,16 @@ set NestedSet {
     member: String
 }
 
+map MapOfPatternString {
+    key: String,
+    value: PatternString,
+}
+
+map MapOfLengthPatternString {
+    key: String,
+    value: LengthPatternString,
+}
+
 @length(min: 1, max: 69)
 map ConBMap {
     key: String,

From e89850f584f84504ca73ed07e29e0d0aa5d8b096 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 16:46:23 +0000
Subject: [PATCH 43/59] Fix broken `RestJsonMalformedPatternReDOSString` test

---
 .../protocol/ServerProtocolTestGenerator.kt   | 36 +++++++++++++++++--
 1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
index 2d61e8011f..ad62f1c8f7 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
@@ -18,6 +18,7 @@ import software.amazon.smithy.model.traits.ErrorTrait
 import software.amazon.smithy.protocoltests.traits.AppliesTo
 import software.amazon.smithy.protocoltests.traits.HttpMalformedRequestTestCase
 import software.amazon.smithy.protocoltests.traits.HttpMalformedRequestTestsTrait
+import software.amazon.smithy.protocoltests.traits.HttpMalformedResponseBodyDefinition
 import software.amazon.smithy.protocoltests.traits.HttpMalformedResponseDefinition
 import software.amazon.smithy.protocoltests.traits.HttpRequestTestCase
 import software.amazon.smithy.protocoltests.traits.HttpRequestTestsTrait
@@ -339,8 +340,13 @@ class ServerProtocolTestGenerator(
             }
 
             is TestCase.MalformedRequestTest -> {
-                // We haven't found any broken `HttpMalformedRequestTest`s yet.
-                it
+                val howToFixIt = BrokenMalformedRequestTests[Pair(codegenContext.serviceShape.id.toString(), it.id)]
+                if (howToFixIt == null) {
+                    it
+                } else {
+                    val fixed = howToFixIt(it.testCase)
+                    TestCase.MalformedRequestTest(fixed)
+                }
             }
         }
     }
@@ -969,7 +975,6 @@ class ServerProtocolTestGenerator(
             FailingTest(RestJsonValidation, "RestJsonMalformedPatternStringOverride_case1", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedPatternUnionOverride_case0", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedPatternUnionOverride_case1", TestType.MalformedRequest),
-            FailingTest(RestJsonValidation, "RestJsonMalformedPatternReDOSString", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedRangeByteOverride_case0", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedRangeByteOverride_case1", TestType.MalformedRequest),
             FailingTest(RestJsonValidation, "RestJsonMalformedRangeFloatOverride_case0", TestType.MalformedRequest),
@@ -1166,6 +1171,25 @@ class ServerProtocolTestGenerator(
         private fun fixRestJsonComplexErrorWithNoMessage(testCase: HttpResponseTestCase): HttpResponseTestCase =
             testCase.toBuilder().putHeader("X-Amzn-Errortype", "aws.protocoltests.restjson#ComplexError").build()
 
+        // TODO(https://github.com/awslabs/smithy/issues/1506)
+        private fun fixRestJsonMalformedPatternReDOSString(testCase: HttpMalformedRequestTestCase): HttpMalformedRequestTestCase {
+            val brokenResponse = testCase.response
+            val brokenBody = brokenResponse.body.get()
+            val fixedBody = HttpMalformedResponseBodyDefinition.builder()
+                .mediaType(brokenBody.mediaType)
+                .contents(
+                    """
+                    { "message" : "1 validation error detected. Value 000000000000000000000000000000000000000000000000000000000000000000000000000000000000! at '/evilString' failed to satisfy constraint: Member must satisfy regular expression pattern: ^([0-9]+)+${'$'}",
+                      "fieldList" : [{"message": "Value 000000000000000000000000000000000000000000000000000000000000000000000000000000000000! at '/evilString' failed to satisfy constraint: Member must satisfy regular expression pattern: ^([0-9]+)+${'$'}", "path": "/evilString"}]}
+                    """.trimIndent(),
+                )
+                .build()
+
+            return testCase.toBuilder()
+                .response(brokenResponse.toBuilder().body(fixedBody).build())
+                .build()
+        }
+
         // These are tests whose definitions in the `awslabs/smithy` repository are wrong.
         // This is because they have not been written from a server perspective, and as such the expected `params` field is incomplete.
         // TODO(https://github.com/awslabs/smithy-rs/issues/1288): Contribute a PR to fix them upstream.
@@ -1248,5 +1272,11 @@ class ServerProtocolTestGenerator(
                 Pair(RestJson, "RestJsonEmptyComplexErrorWithNoMessage") to ::fixRestJsonEmptyComplexErrorWithNoMessage,
                 Pair(RestJson, "RestJsonComplexErrorWithNoMessage") to ::fixRestJsonComplexErrorWithNoMessage,
             )
+
+        private val BrokenMalformedRequestTests: Map<Pair<String, String>, KFunction1<HttpMalformedRequestTestCase, HttpMalformedRequestTestCase>> =
+            // TODO(https://github.com/awslabs/smithy/issues/1506)
+            mapOf(
+                Pair(RestJsonValidation, "RestJsonMalformedPatternReDOSString") to ::fixRestJsonMalformedPatternReDOSString,
+            )
     }
 }

From 995bf0f39043869372355b0538d640b1ce19733e Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Mon, 21 Nov 2022 17:31:43 +0000
Subject: [PATCH 44/59] Move `TraitInfo` to its own module and separate
 string-specific details

---
 .../generators/ConstrainedStringGenerator.kt  | 216 +++++++++---------
 .../server/smithy/generators/TraitInfo.kt     |  15 ++
 2 files changed, 122 insertions(+), 109 deletions(-)
 create mode 100644 codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/TraitInfo.kt

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 9b8a8ec911..218ac72164 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -59,7 +59,8 @@ class ConstrainedStringGenerator(
     private val constraintsInfo: List<TraitInfo> =
         supportedStringConstraintTraits
             .mapNotNull { shape.getTrait(it).orNull() }
-            .mapNotNull(TraitInfo::fromTrait)
+            .mapNotNull(StringTraitInfo::fromTrait)
+            .map(StringTraitInfo::toTraitInfo)
 
     private fun renderTryFrom(inner: String, name: String, constraintViolation: Symbol) {
         writer.rustBlock("impl $name") {
@@ -200,127 +201,124 @@ class ConstrainedStringGenerator(
         }
     }
 }
+private data class Length(val lengthTrait: LengthTrait) : StringTraitInfo() {
+    override fun toTraitInfo(): TraitInfo {
+        return TraitInfo(
+            { rust("Self::check_length(&value)?;") },
+            {
+                docs("Error when a string doesn't satisfy its `@length` requirements.")
+                rust("Length(usize),")
+            },
+            {
+                rust(
+                    """
+                    Self::Length(length) => crate::model::ValidationExceptionField {
+                        message: format!("${lengthTrait.validationErrorMessage()}", length, &path),
+                        path,
+                    },
+                    """,
+                )
+            },
+            this::renderValidationFunction,
+        )
+    }
 
-/**
- * Information needed to render a constraint trait as Rust code.
- */
-private data class TraitInfo(
-    val tryFromCheck: Writable,
-    val constraintViolationVariant: Writable,
-    val asValidationExceptionField: Writable,
-    val validationFunctionDefinition: (constraintViolation: Symbol) -> Writable,
-) {
-    companion object {
-        fun fromTrait(trait: Trait): TraitInfo? {
-            return when (trait) {
-                is LengthTrait -> {
-                    this.fromLengthTrait(trait)
-                }
-
-                is PatternTrait -> {
-                    this.fromPatternTrait(trait)
-                }
-
-                else -> {
-                    null
-                }
+    /**
+     * Renders a `check_length` function to validate the string matches the
+     * required length indicated by the `@length` trait.
+     */
+    private fun renderValidationFunction(constraintViolation: Symbol): Writable {
+        return {
+            val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
+                "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
+            } else if (lengthTrait.min.isPresent) {
+                "${lengthTrait.min.get()} <= length"
+            } else {
+                "length <= ${lengthTrait.max.get()}"
             }
-        }
 
-        private fun fromLengthTrait(lengthTrait: LengthTrait): TraitInfo {
-            return TraitInfo(
-                { rust("Self::check_length(&value)?;") },
-                {
-                    docs("Error when a string doesn't satisfy its `@length` requirements.")
-                    rust("Length(usize),")
-                },
-                {
-                    rust(
-                        """
-                        Self::Length(length) => crate::model::ValidationExceptionField {
-                            message: format!("${lengthTrait.validationErrorMessage()}", length, &path),
-                            path,
-                        },
-                        """,
-                    )
-                },
-                { constraintViolation -> { renderLengthValidation(this, lengthTrait, constraintViolation) } },
-            )
-        }
-
-        private fun fromPatternTrait(patternTrait: PatternTrait): TraitInfo {
-            val pattern = patternTrait.pattern
+            rust(
+                """
+                fn check_length(string: &str) -> Result<(), $constraintViolation> {
+                    let length = string.chars().count();
 
-            return TraitInfo(
-                { rust("let value = Self::check_pattern(value)?;") },
-                {
-                    docs("Error when a string doesn't satisfy its `@pattern`.")
-                    docs("Contains the String that failed the pattern.")
-                    rust("Pattern(String),")
-                },
-                {
-                    rust(
-                        """
-                        Self::Pattern(string) => crate::model::ValidationExceptionField {
-                            message: format!("${patternTrait.validationErrorMessage()}", &string, &path, r##"$pattern"##),
-                            path
-                        },
-                        """,
-                    )
-                },
-                { constraintViolation -> { renderPatternValidation(this, patternTrait, constraintViolation) } },
+                    if $condition {
+                        Ok(())
+                    } else {
+                        Err($constraintViolation::Length(length))
+                    }
+                }
+                """,
             )
         }
     }
 }
 
-/**
- * Renders a `check_length` function to validate the string matches the
- * required length indicated by the `@length` trait.
- */
-private fun renderLengthValidation(writer: RustWriter, lengthTrait: LengthTrait, constraintViolation: Symbol) {
-    val condition = if (lengthTrait.min.isPresent && lengthTrait.max.isPresent) {
-        "(${lengthTrait.min.get()}..=${lengthTrait.max.get()}).contains(&length)"
-    } else if (lengthTrait.min.isPresent) {
-        "${lengthTrait.min.get()} <= length"
-    } else {
-        "length <= ${lengthTrait.max.get()}"
+private data class Pattern(val patternTrait: PatternTrait) : StringTraitInfo() {
+    override fun toTraitInfo(): TraitInfo {
+        val pattern = patternTrait.pattern
+
+        return TraitInfo(
+            { rust("let value = Self::check_pattern(value)?;") },
+            {
+                docs("Error when a string doesn't satisfy its `@pattern`.")
+                docs("Contains the String that failed the pattern.")
+                rust("Pattern(String),")
+            },
+            {
+                rust(
+                    """
+                    Self::Pattern(string) => crate::model::ValidationExceptionField {
+                        message: format!("${patternTrait.validationErrorMessage()}", &string, &path, r##"$pattern"##),
+                        path
+                    },
+                    """,
+                )
+            },
+            this::renderValidationFunction,
+        )
     }
-    writer.rust(
-        """
-        fn check_length(string: &str) -> Result<(), $constraintViolation> {
-            let length = string.chars().count();
 
-            if $condition {
-                Ok(())
-            } else {
-                Err($constraintViolation::Length(length))
-            }
-        }
-        """,
-    )
-}
+    /**
+     * Renders a `check_pattern` function to validate the string matches the
+     * supplied regex in the `@pattern` trait.
+     */
+    private fun renderValidationFunction(constraintViolation: Symbol): Writable {
+        val pattern = patternTrait.pattern
 
-/**
- * Renders a `check_pattern` function to validate the string matches the
- * supplied regex in the `@pattern` trait.
- */
-private fun renderPatternValidation(writer: RustWriter, patternTrait: PatternTrait, constraintViolation: Symbol) {
-    val pattern = patternTrait.pattern
+        return {
+            rustTemplate(
+                """
+                fn check_pattern(string: String) -> Result<String, $constraintViolation> {
+                    static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new(r##"$pattern"##).unwrap());
 
-    writer.rustTemplate(
-        """
-        fn check_pattern(string: String) -> Result<String, $constraintViolation> {
-            static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new(r##"$pattern"##).unwrap());
+                    if REGEX.is_match(&string) {
+                        Ok(string)
+                    } else {
+                        Err($constraintViolation::Pattern(string))
+                    }
+                }
+                """,
+                "Regex" to ServerCargoDependency.Regex.toType(),
+                "OnceCell" to ServerCargoDependency.OnceCell.toType(),
+            )
+        }
+    }
+}
 
-            if REGEX.is_match(&string) {
-                Ok(string)
-            } else {
-                Err($constraintViolation::Pattern(string))
+private sealed class StringTraitInfo {
+    companion object {
+        fun fromTrait(trait: Trait): StringTraitInfo? =
+            when (trait) {
+                is PatternTrait -> {
+                    Pattern(trait)
+                }
+                is LengthTrait -> {
+                    Length(trait)
+                }
+                else -> null
             }
-        }
-        """,
-        "Regex" to ServerCargoDependency.Regex.toType(),
-        "OnceCell" to ServerCargoDependency.OnceCell.toType(),
-    )
+    }
+
+    abstract fun toTraitInfo(): TraitInfo
 }
diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/TraitInfo.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/TraitInfo.kt
new file mode 100644
index 0000000000..3b22531d3c
--- /dev/null
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/TraitInfo.kt
@@ -0,0 +1,15 @@
+package software.amazon.smithy.rust.codegen.server.smithy.generators
+
+import software.amazon.smithy.codegen.core.Symbol
+import software.amazon.smithy.rust.codegen.core.rustlang.Writable
+import software.amazon.smithy.rust.codegen.core.rustlang.rust
+
+/**
+ * Information needed to render a constraint trait as Rust code.
+ */
+data class TraitInfo(
+    val tryFromCheck: Writable,
+    val constraintViolationVariant: Writable,
+    val asValidationExceptionField: Writable,
+    val validationFunctionDefinition: (constraintViolation: Symbol) -> Writable,
+)

From 3e45b9e6e23f602ec6046a9eb5f93912a6f6ca35 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Tue, 22 Nov 2022 13:46:38 +0000
Subject: [PATCH 45/59] Update
 codegen-core/common-test-models/constraints.smithy

Co-authored-by: david-perez <d@vidp.dev>
---
 codegen-core/common-test-models/constraints.smithy | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/codegen-core/common-test-models/constraints.smithy b/codegen-core/common-test-models/constraints.smithy
index 4fd625ce73..ef2fbfac9c 100644
--- a/codegen-core/common-test-models/constraints.smithy
+++ b/codegen-core/common-test-models/constraints.smithy
@@ -378,7 +378,7 @@ string FixedLengthString
 string PatternString
 
 @pattern("[a-f0-5]*")
-@length(min:5, max: 10)
+@length(min: 5, max: 10)
 string LengthPatternString
 
 @mediaType("video/quicktime")

From 309423f9331c9f5d772e276e81bf63741c42bf3f Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Tue, 22 Nov 2022 13:48:20 +0000
Subject: [PATCH 46/59] Fix nits in `constraints.smithy`

---
 codegen-core/common-test-models/constraints.smithy | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/codegen-core/common-test-models/constraints.smithy b/codegen-core/common-test-models/constraints.smithy
index 4fd625ce73..8870d4bdb0 100644
--- a/codegen-core/common-test-models/constraints.smithy
+++ b/codegen-core/common-test-models/constraints.smithy
@@ -101,7 +101,7 @@ operation QueryParamsTargetingMapOfListOfEnumStringOperation {
     errors: [ValidationException]
 }
 
-@http(uri: "/query-params-targeting-map-of-pattern-string", method: "POST")
+@http(uri: "/query-params-targeting-map-of-pattern-string-operation", method: "POST")
 operation QueryParamsTargetingMapOfPatternStringOperation {
     input: QueryParamsTargetingMapOfPatternStringOperationInputOutput,
     output: QueryParamsTargetingMapOfPatternStringOperationInputOutput,
@@ -378,7 +378,7 @@ string FixedLengthString
 string PatternString
 
 @pattern("[a-f0-5]*")
-@length(min:5, max: 10)
+@length(min: 5, max: 10)
 string LengthPatternString
 
 @mediaType("video/quicktime")

From 7a95fe2bac9533cc3d09f9d99bf9af4438d66b5d Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Tue, 22 Nov 2022 13:48:42 +0000
Subject: [PATCH 47/59] Add license to `TraitInfo.kt`

---
 .../rust/codegen/server/smithy/generators/TraitInfo.kt       | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/TraitInfo.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/TraitInfo.kt
index 3b22531d3c..3390382ba1 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/TraitInfo.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/TraitInfo.kt
@@ -1,3 +1,8 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 package software.amazon.smithy.rust.codegen.server.smithy.generators
 
 import software.amazon.smithy.codegen.core.Symbol

From bbb1b818a98813d0b1168157e382baec1e17f02d Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Tue, 22 Nov 2022 13:53:19 +0000
Subject: [PATCH 48/59] Make `StringTraitInfo.fromTrait` not return a nullable

---
 .../server/smithy/generators/ConstrainedStringGenerator.kt | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 218ac72164..c9e5de6be4 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -26,6 +26,7 @@ import software.amazon.smithy.rust.codegen.core.rustlang.rustBlockTemplate
 import software.amazon.smithy.rust.codegen.core.rustlang.rustTemplate
 import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
 import software.amazon.smithy.rust.codegen.core.smithy.makeMaybeConstrained
+import software.amazon.smithy.rust.codegen.core.util.PANIC
 import software.amazon.smithy.rust.codegen.core.util.orNull
 import software.amazon.smithy.rust.codegen.core.util.redactIfNecessary
 import software.amazon.smithy.rust.codegen.server.smithy.PubCrateConstraintViolationSymbolProvider
@@ -59,7 +60,7 @@ class ConstrainedStringGenerator(
     private val constraintsInfo: List<TraitInfo> =
         supportedStringConstraintTraits
             .mapNotNull { shape.getTrait(it).orNull() }
-            .mapNotNull(StringTraitInfo::fromTrait)
+            .map(StringTraitInfo::fromTrait)
             .map(StringTraitInfo::toTraitInfo)
 
     private fun renderTryFrom(inner: String, name: String, constraintViolation: Symbol) {
@@ -308,7 +309,7 @@ private data class Pattern(val patternTrait: PatternTrait) : StringTraitInfo() {
 
 private sealed class StringTraitInfo {
     companion object {
-        fun fromTrait(trait: Trait): StringTraitInfo? =
+        fun fromTrait(trait: Trait): StringTraitInfo =
             when (trait) {
                 is PatternTrait -> {
                     Pattern(trait)
@@ -316,7 +317,7 @@ private sealed class StringTraitInfo {
                 is LengthTrait -> {
                     Length(trait)
                 }
-                else -> null
+                else -> PANIC("StringTraitInfo.fromTrait called with unsupported trait $trait")
             }
     }
 

From fdcd2b76b682dd240d143bfcb2fcc47e75085357 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Tue, 22 Nov 2022 14:09:58 +0000
Subject: [PATCH 49/59] Remove overzealous formatting

---
 .../smithy/rust/codegen/server/smithy/ConstraintsTest.kt     | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ConstraintsTest.kt b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ConstraintsTest.kt
index dfd5e6c002..76821a90dd 100644
--- a/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ConstraintsTest.kt
+++ b/codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ConstraintsTest.kt
@@ -34,7 +34,6 @@ class ConstraintsTest {
 
         structure TestInputOutput {
             map: MapA,
-
             recursive: RecursiveShape
         }
 
@@ -68,7 +67,6 @@ class ConstraintsTest {
         structure StructureA {
             @range(min: 1, max: 69)
             int: Integer,
-
             @required
             string: String
         }
@@ -77,12 +75,9 @@ class ConstraintsTest {
         structure StructureB {
             @pattern("\\w+")
             patternString: String,
-
             @required
             requiredString: String,
-
             mapA: MapA,
-
             @length(min: 1, max: 5)
             mapAPrecedence: MapA
         }

From 4a06c7735a3ed023f3a71915de71112f58116b25 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Tue, 22 Nov 2022 14:11:08 +0000
Subject: [PATCH 50/59] Add some padding to json in
 `fixRestJsonMalformedPatternReDOSString`

---
 .../generators/protocol/ServerProtocolTestGenerator.kt      | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
index ad62f1c8f7..01c5df10e5 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
@@ -1179,8 +1179,10 @@ class ServerProtocolTestGenerator(
                 .mediaType(brokenBody.mediaType)
                 .contents(
                     """
-                    { "message" : "1 validation error detected. Value 000000000000000000000000000000000000000000000000000000000000000000000000000000000000! at '/evilString' failed to satisfy constraint: Member must satisfy regular expression pattern: ^([0-9]+)+${'$'}",
-                      "fieldList" : [{"message": "Value 000000000000000000000000000000000000000000000000000000000000000000000000000000000000! at '/evilString' failed to satisfy constraint: Member must satisfy regular expression pattern: ^([0-9]+)+${'$'}", "path": "/evilString"}]}
+                    {
+                        "message" : "1 validation error detected. Value 000000000000000000000000000000000000000000000000000000000000000000000000000000000000! at '/evilString' failed to satisfy constraint: Member must satisfy regular expression pattern: ^([0-9]+)+${'$'}",
+                        "fieldList" : [{"message": "Value 000000000000000000000000000000000000000000000000000000000000000000000000000000000000! at '/evilString' failed to satisfy constraint: Member must satisfy regular expression pattern: ^([0-9]+)+${'$'}", "path": "/evilString"}]
+                    }
                     """.trimIndent(),
                 )
                 .build()

From 750e49d62fe2cc5b0777772ecd2141a80661774b Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Tue, 22 Nov 2022 14:49:59 +0000
Subject: [PATCH 51/59] Add `compile_regex` function for `@pattern` strings

---
 .../smithy/generators/ConstrainedStringGenerator.kt    | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index c9e5de6be4..fd4ae2e191 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -291,14 +291,20 @@ private data class Pattern(val patternTrait: PatternTrait) : StringTraitInfo() {
             rustTemplate(
                 """
                 fn check_pattern(string: String) -> Result<String, $constraintViolation> {
-                    static REGEX : #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new(r##"$pattern"##).unwrap());
+                    let regex = Self::compile_regex();
 
-                    if REGEX.is_match(&string) {
+                    if regex.is_match(&string) {
                         Ok(string)
                     } else {
                         Err($constraintViolation::Pattern(string))
                     }
                 }
+
+                pub fn compile_regex() -> &'static #{Regex}::Regex {
+                    static REGEX: #{OnceCell}::sync::OnceCell<#{Regex}::Regex> = #{OnceCell}::sync::OnceCell::new();
+
+                    REGEX.get_or_init(|| #{Regex}::Regex::new(r##"$pattern"##).unwrap())
+                }
                 """,
                 "Regex" to ServerCargoDependency.Regex.toType(),
                 "OnceCell" to ServerCargoDependency.OnceCell.toType(),

From 11ee326a0b36cd5948776f29633d43ece8699041 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Tue, 22 Nov 2022 15:00:03 +0000
Subject: [PATCH 52/59] Add helpful error message when regexes fail to compile

---
 .../server/smithy/generators/ConstrainedStringGenerator.kt   | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index fd4ae2e191..041b00803a 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -303,7 +303,10 @@ private data class Pattern(val patternTrait: PatternTrait) : StringTraitInfo() {
                 pub fn compile_regex() -> &'static #{Regex}::Regex {
                     static REGEX: #{OnceCell}::sync::OnceCell<#{Regex}::Regex> = #{OnceCell}::sync::OnceCell::new();
 
-                    REGEX.get_or_init(|| #{Regex}::Regex::new(r##"$pattern"##).unwrap())
+                    REGEX.get_or_init(||
+                        #{Regex}::Regex::new(r##"$pattern"##)
+                            .unwrap_or_else(|_| panic!("The regular expression {} is not supported by the `regex` crate; feel free to file an issue under https://github.com/awslabs/smithy-rs/issues for support", r##"$pattern"##))
+                    )
                 }
                 """,
                 "Regex" to ServerCargoDependency.Regex.toType(),

From cb4d4eef4da911b82c7182ee6b4415a130e4c580 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Tue, 22 Nov 2022 17:20:16 +0000
Subject: [PATCH 53/59] Add missing coverage in `constraints.smithy`

---
 .../common-test-models/constraints.smithy     | 68 ++++++++++++++++++-
 1 file changed, 67 insertions(+), 1 deletion(-)

diff --git a/codegen-core/common-test-models/constraints.smithy b/codegen-core/common-test-models/constraints.smithy
index 8870d4bdb0..8254bf5bbf 100644
--- a/codegen-core/common-test-models/constraints.smithy
+++ b/codegen-core/common-test-models/constraints.smithy
@@ -25,7 +25,9 @@ service ConstraintsService {
         QueryParamsTargetingMapOfListOfEnumStringOperation,
 
         QueryParamsTargetingMapOfPatternStringOperation,
+        QueryParamsTargetingMapOfListOfPatternStringOperation,
         QueryParamsTargetingMapOfLengthPatternStringOperation,
+        QueryParamsTargetingMapOfListOfLengthPatternStringOperation,
 
         HttpPrefixHeadersTargetingLengthMapOperation,
         // TODO(https://github.com/awslabs/smithy-rs/issues/1431)
@@ -108,6 +110,13 @@ operation QueryParamsTargetingMapOfPatternStringOperation {
     errors: [ValidationException]
 }
 
+@http(uri: "/query-params-targeting-map-of-list-of-pattern-string-operation", method: "POST")
+operation QueryParamsTargetingMapOfListOfPatternStringOperation {
+    input: QueryParamsTargetingMapOfListOfPatternStringOperationInputOutput,
+    output: QueryParamsTargetingMapOfListOfPatternStringOperationInputOutput,
+    errors: [ValidationException]
+}
+
 @http(uri: "/query-params-targeting-map-of-length-pattern-string", method: "POST")
 operation QueryParamsTargetingMapOfLengthPatternStringOperation {
     input: QueryParamsTargetingMapOfLengthPatternStringOperationInputOutput,
@@ -115,6 +124,13 @@ operation QueryParamsTargetingMapOfLengthPatternStringOperation {
     errors: [ValidationException],
 }
 
+@http(uri: "/query-params-targeting-map-of-list-of-length-pattern-string-operation", method: "POST")
+operation QueryParamsTargetingMapOfListOfLengthPatternStringOperation {
+    input: QueryParamsTargetingMapOfListOfLengthPatternStringOperationInputOutput,
+    output: QueryParamsTargetingMapOfListOfLengthPatternStringOperationInputOutput,
+    errors: [ValidationException]
+}
+
 @http(uri: "/http-prefix-headers-targeting-length-map-operation", method: "POST")
 operation HttpPrefixHeadersTargetingLengthMapOperation {
     input: HttpPrefixHeadersTargetingLengthMapOperationInputOutput,
@@ -210,11 +226,21 @@ structure QueryParamsTargetingMapOfPatternStringOperationInputOutput {
     mapOfPatternString: MapOfPatternString
 }
 
+structure QueryParamsTargetingMapOfListOfPatternStringOperationInputOutput {
+    @httpQueryParams
+    mapOfListOfPatternString: MapOfListOfPatternString
+}
+
 structure QueryParamsTargetingMapOfLengthPatternStringOperationInputOutput {
     @httpQueryParams
     mapOfLengthPatternString: MapOfLengthPatternString,
 }
 
+structure QueryParamsTargetingMapOfListOfLengthPatternStringOperationInputOutput {
+    @httpQueryParams
+    mapOfLengthPatternString: MapOfListOfLengthPatternString,
+}
+
 structure HttpPrefixHeadersTargetingLengthMapOperationInputOutput {
     @httpPrefixHeaders("X-Prefix-Headers-LengthMap-")
     lengthMap: ConBMap,
@@ -326,7 +352,21 @@ structure ConA {
     // setOfLengthString: SetOfLengthString,
     mapOfLengthString: MapOfLengthString,
 
-    nonStreamingBlob: NonStreamingBlob
+    nonStreamingBlob: NonStreamingBlob,
+
+    patternString: PatternString,
+    mapOfPatternString: MapOfPatternString,
+    listOfPatternString: ListOfPatternString,
+    // TODO(https://github.com/awslabs/smithy-rs/issues/1401): a `set` shape is
+    //  just a `list` shape with `uniqueItems`, which hasn't been implemented yet.
+    // setOfPatternString: SetOfPatternString,
+
+    lengthLengthPatternString: LengthPatternString,
+    mapOfLengthPatternString: MapOfLengthPatternString,
+    listOfLengthPatternString: ListOfLengthPatternString
+    // TODO(https://github.com/awslabs/smithy-rs/issues/1401): a `set` shape is
+    //  just a `list` shape with `uniqueItems`, which hasn't been implemented yet.
+    // setOfLengthPatternString: SetOfLengthPatternString,
 }
 
 map MapOfLengthString {
@@ -349,6 +389,16 @@ map MapOfListOfEnumString {
     value: ListOfEnumString,
 }
 
+map MapOfListOfPatternString {
+    key: PatternString,
+    value: ListOfPatternString
+}
+
+map MapOfListOfLengthPatternString {
+    key: LengthPatternString,
+    value: ListOfLengthPatternString
+}
+
 map MapOfSetOfLengthString {
     key: LengthString,
     // TODO(https://github.com/awslabs/smithy-rs/issues/1401): a `set` shape is
@@ -418,6 +468,14 @@ set SetOfLengthString {
     member: LengthString
 }
 
+set SetOfPatternString {
+    member: PatternString
+}
+
+set SetOfLengthPatternString {
+    member: LengthPatternString
+}
+
 list ListOfLengthString {
     member: LengthString
 }
@@ -426,6 +484,14 @@ list ListOfEnumString {
     member: EnumString
 }
 
+list ListOfPatternString {
+    member: PatternString
+}
+
+list ListOfLengthPatternString {
+    member: LengthPatternString
+}
+
 structure ConB {
     @required
     nice: String,

From be4a85a3c42f881329d30bde74376dd179325beb Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Wed, 23 Nov 2022 10:02:41 +0000
Subject: [PATCH 54/59] Fix examples in `constraints.smithy`

---
 codegen-core/common-test-models/constraints.smithy | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/codegen-core/common-test-models/constraints.smithy b/codegen-core/common-test-models/constraints.smithy
index 8254bf5bbf..0bdfe6d2a1 100644
--- a/codegen-core/common-test-models/constraints.smithy
+++ b/codegen-core/common-test-models/constraints.smithy
@@ -545,12 +545,12 @@ list NestedList {
 // }
 
 map MapOfPatternString {
-    key: String,
+    key: PatternString,
     value: PatternString,
 }
 
 map MapOfLengthPatternString {
-    key: String,
+    key: LengthPatternString,
     value: LengthPatternString,
 }
 

From 105112a61a16aaa737d053a77b2ec73e4d857250 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Wed, 23 Nov 2022 10:21:20 +0000
Subject: [PATCH 55/59] Fix failing test

---
 .../amazon/smithy/rust/codegen/server/smithy/Constraints.kt     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt
index 35211f01fd..9acabf7532 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/Constraints.kt
@@ -94,7 +94,7 @@ fun MemberShape.targetCanReachConstrainedShape(model: Model, symbolProvider: Sym
 
 fun Shape.hasPublicConstrainedWrapperTupleType(model: Model, publicConstrainedTypes: Boolean): Boolean = when (this) {
     is MapShape -> publicConstrainedTypes && this.hasTrait<LengthTrait>()
-    is StringShape -> !this.hasTrait<EnumTrait>() && (publicConstrainedTypes && this.hasTrait<LengthTrait>())
+    is StringShape -> !this.hasTrait<EnumTrait>() && (publicConstrainedTypes && supportedStringConstraintTraits.any(this::hasTrait))
     is MemberShape -> model.expectShape(this.target).hasPublicConstrainedWrapperTupleType(model, publicConstrainedTypes)
     else -> false
 }

From 0d2b6b629ac9df14a33a3734bf91c5258846755e Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Wed, 23 Nov 2022 13:52:31 +0000
Subject: [PATCH 56/59] Combine writables in `ConstrainedStringGenerator`

---
 .../generators/ConstrainedStringGenerator.kt  | 75 +++++++++----------
 1 file changed, 37 insertions(+), 38 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 041b00803a..587b53628e 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -19,10 +19,9 @@ import software.amazon.smithy.rust.codegen.core.rustlang.Visibility
 import software.amazon.smithy.rust.codegen.core.rustlang.Writable
 import software.amazon.smithy.rust.codegen.core.rustlang.docs
 import software.amazon.smithy.rust.codegen.core.rustlang.documentShape
+import software.amazon.smithy.rust.codegen.core.rustlang.join
 import software.amazon.smithy.rust.codegen.core.rustlang.render
 import software.amazon.smithy.rust.codegen.core.rustlang.rust
-import software.amazon.smithy.rust.codegen.core.rustlang.rustBlock
-import software.amazon.smithy.rust.codegen.core.rustlang.rustBlockTemplate
 import software.amazon.smithy.rust.codegen.core.rustlang.rustTemplate
 import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
 import software.amazon.smithy.rust.codegen.core.smithy.makeMaybeConstrained
@@ -64,26 +63,31 @@ class ConstrainedStringGenerator(
             .map(StringTraitInfo::toTraitInfo)
 
     private fun renderTryFrom(inner: String, name: String, constraintViolation: Symbol) {
-        writer.rustBlock("impl $name") {
-            for (traitInfo in constraintsInfo) {
-                rustTemplate("#{ValidationFunction:W}", "ValidationFunction" to traitInfo.validationFunctionDefinition(constraintViolation))
+        writer.rustTemplate(
+            """
+            impl $name {
+                #{ValidationFunctions:W}
             }
-        }
+            """,
+            "ValidationFunctions" to constraintsInfo.map { it.validationFunctionDefinition(constraintViolation) }.join("\n"),
+        )
+
+        writer.rustTemplate(
+            """
+            impl #{TryFrom}<$inner> for $name {
+                type Error = #{ConstraintViolation};
 
-        writer.rustBlockTemplate("impl #{TryFrom}<$inner> for $name", "TryFrom" to RuntimeType.TryFrom) {
-            rustTemplate("type Error = #{ConstraintViolation};", "ConstraintViolation" to constraintViolation)
-            rustBlock(
-                """
                 /// ${rustDocsTryFromMethod(name, inner)}
-                fn try_from(value: $inner) -> Result<Self, Self::Error>
-                """,
-            ) {
-                for (traitInfo in constraintsInfo) {
-                    rustTemplate("#{TryFromCheck:W}", "TryFromCheck" to traitInfo.tryFromCheck)
+                fn try_from(value: $inner) -> Result<Self, Self::Error> {
+                  #{TryFromChecks:W}
+
+                  Ok(Self(value))
                 }
-                rust("Ok(Self(value))")
             }
-        }
+            """,
+            "TryFrom" to RuntimeType.TryFrom,
+            "TryFromChecks" to constraintsInfo.map { it.tryFromCheck }.join("\n"),
+        )
     }
 
     fun render() {
@@ -172,33 +176,28 @@ class ConstrainedStringGenerator(
     }
 
     private fun renderConstraintViolationEnum(writer: RustWriter, shape: StringShape, constraintViolation: Symbol) {
-        writer.rustBlock(
+        writer.rustTemplate(
             """
             ##[derive(Debug, PartialEq)]
-            pub enum ${constraintViolation.name}
-            """,
-        ) {
-            for (traitInfo in constraintsInfo) {
-                rustTemplate(
-                    "#{ConstraintViolationVariant:W}",
-                    "ConstraintViolationVariant" to traitInfo.constraintViolationVariant,
-                )
+            pub enum ${constraintViolation.name} {
+              #{Variants:W}
             }
-        }
+            """,
+            "Variants" to constraintsInfo.map { it.constraintViolationVariant }.join(",\n"),
+        )
 
         if (shape.isReachableFromOperationInput()) {
-            writer.rustBlock("impl ${constraintViolation.name}") {
-                rustBlockTemplate(
-                    "pub(crate) fn as_validation_exception_field(self, path: #{String}) -> crate::model::ValidationExceptionField",
-                    "String" to RuntimeType.String,
-                ) {
-                    rustBlock("match self") {
-                        for (traitInfo in constraintsInfo) {
-                            rustTemplate("#{ValidationExceptionField:W}", "ValidationExceptionField" to traitInfo.asValidationExceptionField)
-                        }
-                    }
+            writer.rustTemplate(
+                """
+                impl ${constraintViolation.name} {
+                     pub(crate) fn as_validation_exception_field(self, path: #{String}) -> crate::model::ValidationExceptionField {
+                       #{ValidationExceptionFields:W}
+                     }
                 }
-            }
+                """,
+                "String" to RuntimeType.String,
+                "ValidationExceptionFields" to constraintsInfo.map { it.asValidationExceptionField }.join("\n"),
+            )
         }
     }
 }

From 3848d34336a400b8f1bb0f49aa81324b4633ae73 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Wed, 23 Nov 2022 14:19:41 +0000
Subject: [PATCH 57/59] Fix uses of `Writable.join`

---
 .../smithy/generators/ConstrainedStringGenerator.kt | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 587b53628e..076c169c7a 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -86,6 +86,7 @@ class ConstrainedStringGenerator(
             }
             """,
             "TryFrom" to RuntimeType.TryFrom,
+            "ConstraintViolation" to constraintViolation,
             "TryFromChecks" to constraintsInfo.map { it.tryFromCheck }.join("\n"),
         )
     }
@@ -190,9 +191,11 @@ class ConstrainedStringGenerator(
             writer.rustTemplate(
                 """
                 impl ${constraintViolation.name} {
-                     pub(crate) fn as_validation_exception_field(self, path: #{String}) -> crate::model::ValidationExceptionField {
-                       #{ValidationExceptionFields:W}
-                     }
+                    pub(crate) fn as_validation_exception_field(self, path: #{String}) -> crate::model::ValidationExceptionField {
+                        match self {
+                            #{ValidationExceptionFields:W}
+                        }
+                    }
                 }
                 """,
                 "String" to RuntimeType.String,
@@ -207,7 +210,7 @@ private data class Length(val lengthTrait: LengthTrait) : StringTraitInfo() {
             { rust("Self::check_length(&value)?;") },
             {
                 docs("Error when a string doesn't satisfy its `@length` requirements.")
-                rust("Length(usize),")
+                rust("Length(usize)")
             },
             {
                 rust(
@@ -263,7 +266,7 @@ private data class Pattern(val patternTrait: PatternTrait) : StringTraitInfo() {
             {
                 docs("Error when a string doesn't satisfy its `@pattern`.")
                 docs("Contains the String that failed the pattern.")
-                rust("Pattern(String),")
+                rust("Pattern(String)")
             },
             {
                 rust(

From fdf88b0de0cae3a4c33c6e4105dbddfb0a9b25dc Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Wed, 23 Nov 2022 14:21:48 +0000
Subject: [PATCH 58/59] Use `expect` over `unwrap_or_else`

---
 .../server/smithy/generators/ConstrainedStringGenerator.kt  | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 076c169c7a..3bf8fddaf9 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -288,6 +288,7 @@ private data class Pattern(val patternTrait: PatternTrait) : StringTraitInfo() {
      */
     private fun renderValidationFunction(constraintViolation: Symbol): Writable {
         val pattern = patternTrait.pattern
+        val errorMessageForUnsupportedRegex = """The regular expression $pattern is not supported by the `regex` crate; feel free to file an issue under https://github.com/awslabs/smithy-rs/issues for support"""
 
         return {
             rustTemplate(
@@ -305,10 +306,7 @@ private data class Pattern(val patternTrait: PatternTrait) : StringTraitInfo() {
                 pub fn compile_regex() -> &'static #{Regex}::Regex {
                     static REGEX: #{OnceCell}::sync::OnceCell<#{Regex}::Regex> = #{OnceCell}::sync::OnceCell::new();
 
-                    REGEX.get_or_init(||
-                        #{Regex}::Regex::new(r##"$pattern"##)
-                            .unwrap_or_else(|_| panic!("The regular expression {} is not supported by the `regex` crate; feel free to file an issue under https://github.com/awslabs/smithy-rs/issues for support", r##"$pattern"##))
-                    )
+                    REGEX.get_or_init(|| #{Regex}::Regex::new(r##"$pattern"##).expect(r##"$errorMessageForUnsupportedRegex"##))
                 }
                 """,
                 "Regex" to ServerCargoDependency.Regex.toType(),

From 53cf34c6b0e0fed2d0289f4659c49894d4f53c05 Mon Sep 17 00:00:00 2001
From: Julian Antonielli <julianantonielli@gmail.com>
Date: Wed, 23 Nov 2022 14:28:09 +0000
Subject: [PATCH 59/59] Use `once_cell::sync::Lazy` over
 `once_cell::sync::OnceCell`

---
 .../server/smithy/generators/ConstrainedStringGenerator.kt    | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
index 3bf8fddaf9..c0ef3c043c 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ConstrainedStringGenerator.kt
@@ -304,9 +304,9 @@ private data class Pattern(val patternTrait: PatternTrait) : StringTraitInfo() {
                 }
 
                 pub fn compile_regex() -> &'static #{Regex}::Regex {
-                    static REGEX: #{OnceCell}::sync::OnceCell<#{Regex}::Regex> = #{OnceCell}::sync::OnceCell::new();
+                    static REGEX: #{OnceCell}::sync::Lazy<#{Regex}::Regex> = #{OnceCell}::sync::Lazy::new(|| #{Regex}::Regex::new(r##"$pattern"##).expect(r##"$errorMessageForUnsupportedRegex"##));
 
-                    REGEX.get_or_init(|| #{Regex}::Regex::new(r##"$pattern"##).expect(r##"$errorMessageForUnsupportedRegex"##))
+                    &REGEX
                 }
                 """,
                 "Regex" to ServerCargoDependency.Regex.toType(),