Backfill message & parse without case sensitivity

codegen-test/build.gradle.kts

@@ -30,21 +30,34 @@ val CodegenTests = listOf(
     CodegenTest("aws.protocoltests.json10#JsonRpc10", "json_rpc10"),
     CodegenTest("aws.protocoltests.json#JsonProtocol", "json_rpc11"),
     CodegenTest("aws.protocoltests.restjson#RestJson", "rest_json"),
-    CodegenTest("aws.protocoltests.restjson#RestJsonExtras", "rest_json_extas"),
-    CodegenTest("aws.protocoltests.restxml#RestXml", "rest_xml"),
-    CodegenTest("aws.protocoltests.query#AwsQuery", "aws_query"),
-    CodegenTest("aws.protocoltests.ec2#AwsEc2", "ec2_query"),
+    CodegenTest("aws.protocoltests.restjson#RestJsonExtras", "rest_json_extras"),
+    CodegenTest(
+        "aws.protocoltests.restxml#RestXml", "rest_xml",
+        extraConfig = """, "codegen": { "addMessageToErrors": false } """
+    ),
+
+    CodegenTest(
+        "aws.protocoltests.query#AwsQuery", "aws_query",
+        extraConfig = """, "codegen": { "addMessageToErrors": false } """
+    ),
+    CodegenTest(
+        "aws.protocoltests.ec2#AwsEc2", "ec2_query",
+        extraConfig = """, "codegen": { "addMessageToErrors": false } """
+    ),
     CodegenTest(
         "aws.protocoltests.restxml.xmlns#RestXmlWithNamespace",
-        "rest_xml_namespace"
+        "rest_xml_namespace",
+        extraConfig = """, "codegen": { "addMessageToErrors": false } """
     ),
     CodegenTest(
         "aws.protocoltests.restxml#RestXmlExtras",
-        "rest_xml_extras"
+        "rest_xml_extras",
+        extraConfig = """, "codegen": { "addMessageToErrors": false } """
     ),
     CodegenTest(
         "aws.protocoltests.restxmlunwrapped#RestXmlExtrasUnwrappedErrors",
-        "rest_xml_extras_unwrapped"
+        "rest_xml_extras_unwrapped",
+        extraConfig = """, "codegen": { "addMessageToErrors": false } """
     ),
     CodegenTest(
         "crate#Config",

codegen-test/model/rest-json-extras.smithy

@@ -62,6 +62,7 @@ service RestJsonExtras {
         PrimitiveIntOp,
         EscapedStringValues,
         NullInNonSparse,
+        CaseInsensitiveErrorOperation
     ]
 }
 
@@ -268,3 +269,23 @@ structure NullInNonSparseOutput {
 operation NullInNonSparse {
     output: NullInNonSparseOutput,
 }
+
+@http(uri: "/error-sensitive", method: "POST")
+operation CaseInsensitiveErrorOperation {
+    errors: [CaseInsensitiveError]
+}
+
+@httpResponseTests([
+    {
+        id: "Upper case error modeled lower case",
+        protocol: "aws.protocols#restJson1",
+        code: 500,
+        body: "{\"Message\": \"hello\"}",
+        headers: { "X-Amzn-Errortype": "CaseInsensitiveError" },
+        params: { message: "hello" }
+    }
+])
+@error("server")
+structure CaseInsensitiveError {
+    message: String
+}

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/CodegenVisitor.kt

@@ -27,6 +27,7 @@ import software.amazon.smithy.rust.codegen.smithy.generators.UnionGenerator
 import software.amazon.smithy.rust.codegen.smithy.generators.implBlock
 import software.amazon.smithy.rust.codegen.smithy.protocols.ProtocolLoader
 import software.amazon.smithy.rust.codegen.smithy.traits.SyntheticInputTrait
+import software.amazon.smithy.rust.codegen.smithy.transformers.AddErrorMessage
 import software.amazon.smithy.rust.codegen.smithy.transformers.RecursiveShapeBoxer
 import software.amazon.smithy.rust.codegen.util.CommandFailed
 import software.amazon.smithy.rust.codegen.util.getTrait
@@ -74,7 +75,9 @@ class CodegenVisitor(context: PluginContext, private val codegenDecorator: RustC
         httpGenerator = protocolGenerator.buildProtocolGenerator(protocolConfig)
     }
 
-    private fun baselineTransform(model: Model) = model.let(RecursiveShapeBoxer::transform)
+    private fun baselineTransform(model: Model) =
+        model.let(RecursiveShapeBoxer::transform)
+            .letIf(settings.codegenConfig.addMessageToErrors, AddErrorMessage::transform)
 
     fun execute() {
         logger.info("generating Rust client...")

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/RustSettings.kt

@@ -28,14 +28,25 @@ private const val RUNTIME_CONFIG = "runtimeConfig"
 private const val CODEGEN_SETTINGS = "codegen"
 private const val LICENSE = "license"
 
-data class CodegenConfig(val renameExceptions: Boolean = true, val includeFluentClient: Boolean = true, val formatTimeoutSeconds: Int = 20) {
+data class CodegenConfig(
+    // / Rename `Exception` to `Error` in the generated SDK
+    val renameExceptions: Boolean = true,
+    // / Include a fluent client in the generated SDK
+    val includeFluentClient: Boolean = true,
+    // / Add a message field to all shapes that have the error trait
+    val addMessageToErrors: Boolean = true,
+    // / Timeout when running `cargo fmt` on a generate service
+    val formatTimeoutSeconds: Int = 20
+) {
     companion object {
         fun fromNode(node: Optional<ObjectNode>): CodegenConfig {
             return if (node.isPresent) {
                 CodegenConfig(
                     node.get().getBooleanMemberOrDefault("renameErrors", true),
                     node.get().getBooleanMemberOrDefault("includeFluentClient", true),
-                    node.get().getNumberMemberOrDefault("formatTimeoutSeconds", 20).toInt()
+                    node.get().getBooleanMemberOrDefault("addMessageToErrors", true),
+                    node.get().getNumberMemberOrDefault("formatTimeoutSeconds", 20).toInt(),
+
                 )
             } else {
                 CodegenConfig()

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/generators/HttpProtocolTestGenerator.kt

@@ -426,6 +426,8 @@ class HttpProtocolTestGenerator(
         private val AwsJson11 = "aws.protocoltests.json#JsonProtocol"
         private val RestJson = "aws.protocoltests.restjson#RestJson"
         private val RestXml = "aws.protocoltests.restxml#RestXml"
+        private val AwsQuery = "aws.protocoltests.query#AwsQuery"
+        private val Ec2Query = "aws.protocoltests.ec2#AwsEc2"
         private val ExpectFail = setOf<FailingTest>()
         private val RunOnly: Set<String>? = null
 

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/generators/error/ErrorGenerator.kt

@@ -20,6 +20,7 @@ import software.amazon.smithy.rust.codegen.smithy.RuntimeType.Companion.StdError
 import software.amazon.smithy.rust.codegen.smithy.RuntimeType.Companion.stdfmt
 import software.amazon.smithy.rust.codegen.smithy.RustSymbolProvider
 import software.amazon.smithy.rust.codegen.smithy.letIf
+import software.amazon.smithy.rust.codegen.smithy.transformers.errorMessageMember
 import software.amazon.smithy.rust.codegen.util.dq
 import software.amazon.smithy.rust.codegen.util.getTrait
 
@@ -71,9 +72,8 @@ class ErrorGenerator(
 
     private fun renderError() {
         val symbol = symbolProvider.toSymbol(shape)
-        val messageShape =
-            shape.getMember("message").or { shape.getMember("Message") }.or { shape.getMember("errorMessage") }
-        val message = messageShape.map { "self.${symbolProvider.toMemberName(it)}.as_deref()" }.orElse("None")
+        val messageShape = shape.errorMessageMember()
+        val message = messageShape?.let { "self.${symbolProvider.toMemberName(it)}.as_deref()" } ?: "None"
         val errorKindT = RuntimeType.errorKind(symbolProvider.config().runtimeConfig)
         writer.rustBlock("impl ${symbol.name}") {
             val retryKindWriteable = shape.modeledRetryKind(error)?.writable(symbolProvider.config().runtimeConfig)
@@ -97,7 +97,7 @@ class ErrorGenerator(
                     "$symbolName [${shape.id.name}]"
                 }
                 write("write!(f, ${errorDesc.dq()})?;")
-                messageShape.map {
+                messageShape?.let {
                     ifSet(it, symbolProvider.toSymbol(it), "&self.message") { field ->
                         write("""write!(f, ": {}", $field)?;""")
                     }

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/protocols/HttpBoundProtocolGenerator.kt

@@ -19,7 +19,9 @@ import software.amazon.smithy.model.traits.TimestampFormatTrait
 import software.amazon.smithy.rust.codegen.rustlang.Attribute
 import software.amazon.smithy.rust.codegen.rustlang.RustWriter
 import software.amazon.smithy.rust.codegen.rustlang.Writable
+import software.amazon.smithy.rust.codegen.rustlang.assignment
 import software.amazon.smithy.rust.codegen.rustlang.rust
+import software.amazon.smithy.rust.codegen.rustlang.rustBlock
 import software.amazon.smithy.rust.codegen.rustlang.rustBlockTemplate
 import software.amazon.smithy.rust.codegen.rustlang.rustTemplate
 import software.amazon.smithy.rust.codegen.rustlang.withBlock
@@ -37,6 +39,7 @@ import software.amazon.smithy.rust.codegen.smithy.generators.setterName
 import software.amazon.smithy.rust.codegen.smithy.isOptional
 import software.amazon.smithy.rust.codegen.smithy.protocols.parse.StructuredDataParserGenerator
 import software.amazon.smithy.rust.codegen.smithy.protocols.serialize.StructuredDataSerializerGenerator
+import software.amazon.smithy.rust.codegen.smithy.transformers.errorMessageMember
 import software.amazon.smithy.rust.codegen.util.dq
 import software.amazon.smithy.rust.codegen.util.expectMember
 import software.amazon.smithy.rust.codegen.util.hasStreamingMember
@@ -288,24 +291,44 @@ class HttpBoundProtocolGenerator(
                         let error_code = match generic.code() {
                             Some(code) => code,
                             None => return Err(#{error_symbol}::unhandled(generic))
-                        };""",
+                        };
+
+                        let _error_message = generic.message().map(|msg|msg.to_owned());
+                        """,
                         "error_symbol" to errorSymbol,
                     )
                     withBlock("Err(match error_code {", "})") {
                         operationShape.errors.forEach { error ->
                             val errorShape = model.expectShape(error, StructureShape::class.java)
                             val variantName = symbolProvider.toSymbol(model.expectShape(error)).name
                             withBlock(
-                                "${httpBindingResolver.errorCode(errorShape).dq()} => #1T { meta: generic, kind: #1TKind::$variantName({",
+                                "${
+                                httpBindingResolver.errorCode(errorShape).dq()
+                                } => #1T { meta: generic, kind: #1TKind::$variantName({",
                                 "})},",
                                 errorSymbol
                             ) {
-                                renderShapeParser(
-                                    operationShape,
-                                    errorShape,
-                                    httpBindingResolver.errorResponseBindings(errorShape),
-                                    errorSymbol
-                                )
+                                Attribute.AllowUnusedMut.render(this)
+                                assignment("mut tmp") {
+                                    rustBlock("") {
+                                        renderShapeParser(
+                                            operationShape,
+                                            errorShape,
+                                            httpBindingResolver.errorResponseBindings(errorShape),
+                                            errorSymbol
+                                        )
+                                    }
+                                }
+                                if (errorShape.errorMessageMember() != null) {
+                                    rust(
+                                        """
+                                        if (&tmp.message).is_none() {
+                                            tmp.message = _error_message;
+                                        }
+                                        """
+                                    )
+                                }
+                                rust("tmp")
                             }
                         }
                         rust("_ => #T::generic(generic)", errorSymbol)

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/transformers/AddErrorMessage.kt

@@ -0,0 +1,28 @@
+package software.amazon.smithy.rust.codegen.smithy.transformers
+
+import software.amazon.smithy.model.Model
+import software.amazon.smithy.model.shapes.MemberShape
+import software.amazon.smithy.model.shapes.ShapeId
+import software.amazon.smithy.model.shapes.StructureShape
+import software.amazon.smithy.model.traits.ErrorTrait
+import software.amazon.smithy.model.transform.ModelTransformer
+import software.amazon.smithy.rust.codegen.util.hasTrait
+import software.amazon.smithy.rust.codegen.util.orNull
+import java.util.logging.Logger
+
+fun StructureShape.errorMessageMember(): MemberShape? = this.getMember("message").or { this.getMember("Message") }.orNull()
+
+object AddErrorMessage {
+    private val logger = Logger.getLogger("AddErrorMessage")
+    fun transform(model: Model): Model {
+        return ModelTransformer.create().mapShapes(model) { shape ->
+            val addMessageField = shape.hasTrait<ErrorTrait>() && shape is StructureShape && shape.errorMessageMember() == null
+            if (addMessageField && shape is StructureShape) {
+                logger.info("Adding message field to ${shape.id}")
+                shape.toBuilder().addMember("message", ShapeId.from("smithy.api#String")).build()
+            } else {
+                shape
+            }
+        }
+    }
+}