Accept only true and false for env disabling S3 Express

This commit addresses #3433 (comment)

aws/rust-runtime/aws-inlineable/Cargo.toml

@@ -37,6 +37,7 @@ tracing = "0.1"
 aws-smithy-async = { path = "../../../rust-runtime/aws-smithy-async", features = ["test-util"] }
 aws-smithy-http = { path = "../../../rust-runtime/aws-smithy-http", features = ["rt-tokio"] }
 aws-smithy-runtime-api = { path = "../../../rust-runtime/aws-smithy-runtime-api", features = ["test-util"] }
+proptest = "1"
 tempfile = "3.6.0"
 tokio = { version = "1.23.1", features = ["macros", "rt", "io-util"] }
 

aws/rust-runtime/aws-inlineable/src/s3_express.rs

@@ -690,18 +690,18 @@ pub(crate) mod runtime_plugin {
                 .is_none()
             {
                 match env.get(env::S3_DISABLE_EXPRESS_SESSION_AUTH) {
-                    Ok(value)
-                        if value.eq_ignore_ascii_case("true")
-                            || value.eq_ignore_ascii_case("false") =>
-                    {
+                    Ok(value) if valid_environment_variable_value(&value) => {
                         let value = value
-                            .to_lowercase()
                             .parse::<bool>()
-                            .expect("just checked to be a bool-valued string");
+                            .expect("just checked to be a valid bool-valued string");
                         layer.store_or_unset(Some(crate::config::DisableS3ExpressSessionAuth(
                             value,
                         )));
                     }
+                    Ok(value) => panic!(
+                        "Must provide either `true` or `false` for an environment variable `{}`, but got {}",
+                        env::S3_DISABLE_EXPRESS_SESSION_AUTH,
+                        value),
                     _ => {
                         // TODO(aws-sdk-rust#1073): Transfer a value of
                         //  `s3_disable_express_session_auth` from a profile file to `layer`
@@ -715,6 +715,10 @@ pub(crate) mod runtime_plugin {
         }
     }
 
+    fn valid_environment_variable_value(value: &str) -> bool {
+        value == "true" || value == "false"
+    }
+
     impl RuntimePlugin for S3ExpressRuntimePlugin {
         fn config(&self) -> Option<FrozenLayer> {
             Some(self.config.clone())
@@ -724,6 +728,8 @@ pub(crate) mod runtime_plugin {
     #[cfg(test)]
     mod tests {
         use super::*;
+        use proptest::prelude::*;
+        use proptest::proptest;
 
         #[test]
         fn disable_option_set_from_service_client_should_take_the_highest_precedence() {
@@ -764,8 +770,8 @@ pub(crate) mod runtime_plugin {
             );
         }
 
-        #[should_panic]
         #[test]
+        #[should_panic]
         fn disable_option_set_from_profile_file_should_take_the_lowest_precedence() {
             // TODO(aws-sdk-rust#1073): Implement a test that mimics only setting
             //  `s3_disable_express_session_auth` in a profile file
@@ -785,5 +791,20 @@ pub(crate) mod runtime_plugin {
                 .load::<crate::config::DisableS3ExpressSessionAuth>()
                 .is_none());
         }
+
+        proptest! {
+            #[test]
+            #[should_panic]
+            fn env_value_other_than_case_sensitive_true_or_false_should_result_in_panic(
+                invalid_env_var_value in any::<String>()
+                    .prop_filter("Use only invalid values for panic test",
+                                |s| !valid_environment_variable_value(&s))
+            ) {
+                let _ = S3ExpressRuntimePlugin::new_with(
+                    Layer::new("test").freeze(),
+                    Env::from_slice(&[(super::env::S3_DISABLE_EXPRESS_SESSION_AUTH, &invalid_env_var_value)]),
+                );
+            }
+        }
     }
 }

aws/sdk-codegen/src/main/kotlin/software/amazon/smithy/rustsdk/customize/s3/S3ExpressDecorator.kt

@@ -229,6 +229,7 @@ private fun s3ExpressDependencies(runtimeConfig: RuntimeConfig) =
         CargoDependency.Hex,
         CargoDependency.Hmac,
         CargoDependency.Lru,
+        CargoDependency.Proptest,
         CargoDependency.Sha2,
         CargoDependency.smithyAsync(runtimeConfig),
         CargoDependency.smithyRuntimeApiClient(runtimeConfig),

codegen-client/src/main/kotlin/software/amazon/smithy/rust/codegen/client/smithy/generators/client/FluentClientGenerator.kt

@@ -130,6 +130,7 @@ class FluentClientGenerator(
                     /// - Retries or timeouts are enabled without a `sleep_impl` configured.
                     /// - Identity caching is enabled without a `sleep_impl` and `time_source` configured.
                     /// - No `behavior_version` is provided.
+                    /// - Base client-level runtime plugins could not be created.
                     ///
                     /// The panic message for each of these will have instructions on how to resolve them.
                     ##[track_caller]

codegen-core/src/main/kotlin/software/amazon/smithy/rust/codegen/core/rustlang/CargoDependency.kt

@@ -277,6 +277,8 @@ data class CargoDependency(
         val Hound: CargoDependency = CargoDependency("hound", CratesIo("3.4.0"), DependencyScope.Dev)
         val PrettyAssertions: CargoDependency =
             CargoDependency("pretty_assertions", CratesIo("1.3.0"), DependencyScope.Dev)
+        val Proptest: CargoDependency =
+            CargoDependency("proptest", CratesIo("1"), DependencyScope.Dev)
         val SerdeJson: CargoDependency = CargoDependency("serde_json", CratesIo("1.0.0"), DependencyScope.Dev)
         val Smol: CargoDependency = CargoDependency("smol", CratesIo("1.2.0"), DependencyScope.Dev)
         val TempFile: CargoDependency = CargoDependency("tempfile", CratesIo("3.2.0"), DependencyScope.Dev)