Fix @length-constrained collection shapes whose members are not con…

…strained The generated code these should have emitted was fixed in #2085 (it's bug number 2), but code generation is still crashing because the call to calculate the inner constraint violation symbol is performed _before_ checking that the collection's member can reach a constrained shape. The test that #2085 added in `constraints.smithy`: ```smithy @Length(max: 69) list LengthList { member: ConB } ``` was not exercising what it should have, since `ConB`, is its name hints at, is a constrained structure shape.
smithy-lang · Dec 14, 2022 · 093dd12 · 093dd12
1 parent 2cc7c24
commit 093dd12
Show file tree

Hide file tree

Showing 3 changed files with 12 additions and 7 deletions.
diff --git a/codegen-core/common-test-models/constraints.smithy b/codegen-core/common-test-models/constraints.smithy
@@ -837,21 +837,25 @@ list RecursiveList {
 }
 
 list ConBList {
-    member: LengthList
+    member: ConBListInner
+}
+
+list ConBListInner {
+    member: ConB
 }
 
 @length(max: 69)
 list LengthList {
-    member: ConB
+    member: String
 }
 
 // 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.
 // set ConBSet {
-//     member: NestedSet
+//     member: ConBSetInner
 // }
 //
-// set NestedSet {
+// set ConBSetInner {
 //     member: String
 // }
 

diff --git a/...in/software/amazon/smithy/rust/codegen/server/smithy/ConstraintViolationSymbolProvider.kt b/...in/software/amazon/smithy/rust/codegen/server/smithy/ConstraintViolationSymbolProvider.kt
@@ -106,7 +106,9 @@ class ConstraintViolationSymbolProvider(
     }
 
     override fun toSymbol(shape: Shape): Symbol {
-        check(shape.canReachConstrainedShape(model, base))
+        check(shape.canReachConstrainedShape(model, base)) {
+            "`ConstraintViolationSymbolProvider` was called on shape that does not reach a constrained shape: $shape"
+        }
 
         return when (shape) {
             is MapShape, is CollectionShape, is UnionShape -> {

diff --git a/...e/amazon/smithy/rust/codegen/server/smithy/generators/UnconstrainedCollectionGenerator.kt b/...e/amazon/smithy/rust/codegen/server/smithy/generators/UnconstrainedCollectionGenerator.kt
@@ -89,8 +89,6 @@ class UnconstrainedCollectionGenerator(
     }
 
     private fun renderTryFromUnconstrainedForConstrained(writer: RustWriter) {
-        val innerConstraintViolationSymbol = constraintViolationSymbolProvider.toSymbol(innerShape)
-
         writer.rustBlock("impl std::convert::TryFrom<$name> for #{T}", constrainedSymbol) {
             rust("type Error = #T;", constraintViolationSymbol)
 
@@ -106,6 +104,7 @@ class UnconstrainedCollectionGenerator(
                     } else {
                         constrainedShapeSymbolProvider.toSymbol(innerShape)
                     }
+                    val innerConstraintViolationSymbol = constraintViolationSymbolProvider.toSymbol(innerShape)
 
                     rustTemplate(
                         """