Split RuntimeError and RequestRejection by protocol (#2517)

As outlined in the [Protocol Specific Errors] of the [Service Builder
Improvements RFC], `RuntimeError` should be split up into smaller,
protocol specific, errors which accurately model the failure cases of
each protocol.

The same goes for `RequestRejection`.

Closes #1703.

[Protocol Specific Errors]: https://github.com/awslabs/smithy-rs/blob/main/design/src/rfcs/rfc0020_service_builder.md#protocol-specific-errors
[Service Builder Improvements RFC]: https://github.com/awslabs/smithy-rs/blob/main/design/src/rfcs/rfc0020_service_builder.md

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerCodegenVisitor.kt

@@ -118,15 +118,15 @@ open class ServerCodegenVisitor(
 
         val baseModel = baselineTransform(context.model)
         val service = settings.getService(baseModel)
-        val (protocol, generator) =
+        val (protocolShape, protocolGeneratorFactory) =
             ServerProtocolLoader(
                 codegenDecorator.protocols(
                     service.id,
                     ServerProtocolLoader.DefaultProtocols,
                 ),
             )
                 .protocolFor(context.model, service)
-        protocolGeneratorFactory = generator
+        this.protocolGeneratorFactory = protocolGeneratorFactory
 
         model = codegenDecorator.transformModel(service, baseModel)
 
@@ -145,7 +145,7 @@ open class ServerCodegenVisitor(
             serverSymbolProviders.symbolProvider,
             null,
             service,
-            protocol,
+            protocolShape,
             settings,
             serverSymbolProviders.unconstrainedShapeSymbolProvider,
             serverSymbolProviders.constrainedShapeSymbolProvider,
@@ -169,7 +169,7 @@ open class ServerCodegenVisitor(
             settings.codegenConfig,
             codegenContext.expectModuleDocProvider(),
         )
-        protocolGenerator = protocolGeneratorFactory.buildProtocolGenerator(codegenContext)
+        protocolGenerator = this.protocolGeneratorFactory.buildProtocolGenerator(codegenContext)
     }
 
     /**
@@ -315,7 +315,12 @@ open class ServerCodegenVisitor(
         writer: RustWriter,
     ) {
         if (codegenContext.settings.codegenConfig.publicConstrainedTypes || shape.isReachableFromOperationInput()) {
-            val serverBuilderGenerator = ServerBuilderGenerator(codegenContext, shape, validationExceptionConversionGenerator)
+            val serverBuilderGenerator = ServerBuilderGenerator(
+                codegenContext,
+                shape,
+                validationExceptionConversionGenerator,
+                protocolGenerator.protocol,
+            )
             serverBuilderGenerator.render(rustCrate, writer)
 
             if (codegenContext.settings.codegenConfig.publicConstrainedTypes) {
@@ -336,7 +341,12 @@ open class ServerCodegenVisitor(
 
         if (!codegenContext.settings.codegenConfig.publicConstrainedTypes) {
             val serverBuilderGeneratorWithoutPublicConstrainedTypes =
-                ServerBuilderGeneratorWithoutPublicConstrainedTypes(codegenContext, shape, validationExceptionConversionGenerator)
+                ServerBuilderGeneratorWithoutPublicConstrainedTypes(
+                    codegenContext,
+                    shape,
+                    validationExceptionConversionGenerator,
+                    protocolGenerator.protocol,
+                )
             serverBuilderGeneratorWithoutPublicConstrainedTypes.render(rustCrate, writer)
 
             writer.implBlock(codegenContext.symbolProvider.toSymbol(shape)) {

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerRuntimeType.kt

@@ -5,7 +5,6 @@
 
 package software.amazon.smithy.rust.codegen.server.smithy
 
-import software.amazon.smithy.rust.codegen.core.rustlang.InlineDependency
 import software.amazon.smithy.rust.codegen.core.smithy.RuntimeConfig
 import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
 
@@ -15,17 +14,11 @@ import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
  * For a runtime type that is used in the client, or in both the client and the server, use [RuntimeType] directly.
  */
 object ServerRuntimeType {
-    fun forInlineDependency(inlineDependency: InlineDependency) = RuntimeType("crate::${inlineDependency.name}", inlineDependency)
+    fun router(runtimeConfig: RuntimeConfig) =
+        ServerCargoDependency.smithyHttpServer(runtimeConfig).toType().resolve("routing::Router")
 
-    fun router(runtimeConfig: RuntimeConfig) = ServerCargoDependency.smithyHttpServer(runtimeConfig).toType().resolve("routing::Router")
-
-    fun runtimeError(runtimeConfig: RuntimeConfig) = ServerCargoDependency.smithyHttpServer(runtimeConfig).toType().resolve("runtime_error::RuntimeError")
-
-    fun requestRejection(runtimeConfig: RuntimeConfig) = ServerCargoDependency.smithyHttpServer(runtimeConfig).toType().resolve("rejection::RequestRejection")
-
-    fun responseRejection(runtimeConfig: RuntimeConfig) = ServerCargoDependency.smithyHttpServer(runtimeConfig).toType().resolve("rejection::ResponseRejection")
-
-    fun protocol(name: String, path: String, runtimeConfig: RuntimeConfig) = ServerCargoDependency.smithyHttpServer(runtimeConfig).toType().resolve("proto::$path::$name")
+    fun protocol(name: String, path: String, runtimeConfig: RuntimeConfig) =
+        ServerCargoDependency.smithyHttpServer(runtimeConfig).toType().resolve("proto::$path::$name")
 
     fun protocol(runtimeConfig: RuntimeConfig) = protocol("Protocol", "", runtimeConfig)
 }

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/customizations/CustomValidationExceptionWithReasonDecorator.kt

@@ -23,7 +23,6 @@ import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
 import software.amazon.smithy.rust.codegen.core.smithy.RustSymbolProvider
 import software.amazon.smithy.rust.codegen.core.util.getTrait
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
-import software.amazon.smithy.rust.codegen.server.smithy.ServerRuntimeType
 import software.amazon.smithy.rust.codegen.server.smithy.customize.ServerCodegenDecorator
 import software.amazon.smithy.rust.codegen.server.smithy.generators.BlobLength
 import software.amazon.smithy.rust.codegen.server.smithy.generators.CollectionTraitInfo
@@ -35,6 +34,7 @@ import software.amazon.smithy.rust.codegen.server.smithy.generators.StringTraitI
 import software.amazon.smithy.rust.codegen.server.smithy.generators.ValidationExceptionConversionGenerator
 import software.amazon.smithy.rust.codegen.server.smithy.generators.isKeyConstrained
 import software.amazon.smithy.rust.codegen.server.smithy.generators.isValueConstrained
+import software.amazon.smithy.rust.codegen.server.smithy.generators.protocol.ServerProtocol
 import software.amazon.smithy.rust.codegen.server.smithy.validationErrorMessage
 
 /**
@@ -67,11 +67,7 @@ class ValidationExceptionWithReasonConversionGenerator(private val codegenContex
     override val shapeId: ShapeId =
         ShapeId.from(codegenContext.settings.codegenConfig.experimentalCustomValidationExceptionWithReasonPleaseDoNotUse)
 
-    override fun renderImplFromConstraintViolationForRequestRejection(): Writable = writable {
-        val codegenScope = arrayOf(
-            "RequestRejection" to ServerRuntimeType.requestRejection(codegenContext.runtimeConfig),
-            "From" to RuntimeType.From,
-        )
+    override fun renderImplFromConstraintViolationForRequestRejection(protocol: ServerProtocol): Writable = writable {
         rustTemplate(
             """
             impl #{From}<ConstraintViolation> for #{RequestRejection} {
@@ -89,7 +85,8 @@ class ValidationExceptionWithReasonConversionGenerator(private val codegenContex
                 }
             }
             """,
-            *codegenScope,
+            "RequestRejection" to protocol.requestRejection(codegenContext.runtimeConfig),
+            "From" to RuntimeType.From,
         )
     }
 

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/customizations/SmithyValidationExceptionDecorator.kt

@@ -23,7 +23,6 @@ import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
 import software.amazon.smithy.rust.codegen.core.smithy.RustSymbolProvider
 import software.amazon.smithy.rust.codegen.core.util.getTrait
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
-import software.amazon.smithy.rust.codegen.server.smithy.ServerRuntimeType
 import software.amazon.smithy.rust.codegen.server.smithy.customize.ServerCodegenDecorator
 import software.amazon.smithy.rust.codegen.server.smithy.generators.BlobLength
 import software.amazon.smithy.rust.codegen.server.smithy.generators.CollectionTraitInfo
@@ -34,6 +33,7 @@ import software.amazon.smithy.rust.codegen.server.smithy.generators.TraitInfo
 import software.amazon.smithy.rust.codegen.server.smithy.generators.ValidationExceptionConversionGenerator
 import software.amazon.smithy.rust.codegen.server.smithy.generators.isKeyConstrained
 import software.amazon.smithy.rust.codegen.server.smithy.generators.isValueConstrained
+import software.amazon.smithy.rust.codegen.server.smithy.generators.protocol.ServerProtocol
 import software.amazon.smithy.rust.codegen.server.smithy.validationErrorMessage
 
 /**
@@ -66,11 +66,7 @@ class SmithyValidationExceptionConversionGenerator(private val codegenContext: S
     }
     override val shapeId: ShapeId = SHAPE_ID
 
-    override fun renderImplFromConstraintViolationForRequestRejection(): Writable = writable {
-        val codegenScope = arrayOf(
-            "RequestRejection" to ServerRuntimeType.requestRejection(codegenContext.runtimeConfig),
-            "From" to RuntimeType.From,
-        )
+    override fun renderImplFromConstraintViolationForRequestRejection(protocol: ServerProtocol): Writable = writable {
         rustTemplate(
             """
             impl #{From}<ConstraintViolation> for #{RequestRejection} {
@@ -87,7 +83,8 @@ class SmithyValidationExceptionConversionGenerator(private val codegenContext: S
                 }
             }
             """,
-            *codegenScope,
+            "RequestRejection" to protocol.requestRejection(codegenContext.runtimeConfig),
+            "From" to RuntimeType.From,
         )
     }
 

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ServerBuilderGenerator.kt

@@ -46,8 +46,8 @@ import software.amazon.smithy.rust.codegen.core.util.letIf
 import software.amazon.smithy.rust.codegen.core.util.redactIfNecessary
 import software.amazon.smithy.rust.codegen.core.util.toSnakeCase
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
-import software.amazon.smithy.rust.codegen.server.smithy.ServerRuntimeType
 import software.amazon.smithy.rust.codegen.server.smithy.canReachConstrainedShape
+import software.amazon.smithy.rust.codegen.server.smithy.generators.protocol.ServerProtocol
 import software.amazon.smithy.rust.codegen.server.smithy.hasConstraintTraitOrTargetHasConstraintTrait
 import software.amazon.smithy.rust.codegen.server.smithy.targetCanReachConstrainedShape
 import software.amazon.smithy.rust.codegen.server.smithy.traits.ConstraintViolationRustBoxTrait
@@ -92,6 +92,7 @@ class ServerBuilderGenerator(
     val codegenContext: ServerCodegenContext,
     private val shape: StructureShape,
     private val customValidationExceptionWithReasonConversionGenerator: ValidationExceptionConversionGenerator,
+    private val protocol: ServerProtocol,
 ) {
     companion object {
         /**
@@ -148,7 +149,7 @@ class ServerBuilderGenerator(
         ServerBuilderConstraintViolations(codegenContext, shape, takeInUnconstrainedTypes, customValidationExceptionWithReasonConversionGenerator)
 
     private val codegenScope = arrayOf(
-        "RequestRejection" to ServerRuntimeType.requestRejection(runtimeConfig),
+        "RequestRejection" to protocol.requestRejection(codegenContext.runtimeConfig),
         "Structure" to structureSymbol,
         "From" to RuntimeType.From,
         "TryFrom" to RuntimeType.TryFrom,
@@ -222,7 +223,8 @@ class ServerBuilderGenerator(
             """
             #{Converter:W}
             """,
-            "Converter" to customValidationExceptionWithReasonConversionGenerator.renderImplFromConstraintViolationForRequestRejection(),
+            "Converter" to
+                customValidationExceptionWithReasonConversionGenerator.renderImplFromConstraintViolationForRequestRejection(protocol),
         )
     }
 

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ServerBuilderGeneratorWithoutPublicConstrainedTypes.kt

@@ -29,7 +29,7 @@ import software.amazon.smithy.rust.codegen.core.smithy.isOptional
 import software.amazon.smithy.rust.codegen.core.smithy.makeOptional
 import software.amazon.smithy.rust.codegen.core.smithy.module
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext
-import software.amazon.smithy.rust.codegen.server.smithy.ServerRuntimeType
+import software.amazon.smithy.rust.codegen.server.smithy.generators.protocol.ServerProtocol
 import software.amazon.smithy.rust.codegen.server.smithy.withInMemoryInlineModule
 
 /**
@@ -49,6 +49,7 @@ class ServerBuilderGeneratorWithoutPublicConstrainedTypes(
     private val codegenContext: ServerCodegenContext,
     shape: StructureShape,
     validationExceptionConversionGenerator: ValidationExceptionConversionGenerator,
+    protocol: ServerProtocol,
 ) {
     companion object {
         /**
@@ -85,7 +86,7 @@ class ServerBuilderGeneratorWithoutPublicConstrainedTypes(
         ServerBuilderConstraintViolations(codegenContext, shape, builderTakesInUnconstrainedTypes = false, validationExceptionConversionGenerator)
 
     private val codegenScope = arrayOf(
-        "RequestRejection" to ServerRuntimeType.requestRejection(codegenContext.runtimeConfig),
+        "RequestRejection" to protocol.requestRejection(codegenContext.runtimeConfig),
         "Structure" to structureSymbol,
         "From" to RuntimeType.From,
         "TryFrom" to RuntimeType.TryFrom,

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ValidationExceptionConversionGenerator.kt

@@ -13,6 +13,7 @@ import software.amazon.smithy.model.shapes.StringShape
 import software.amazon.smithy.model.traits.EnumTrait
 import software.amazon.smithy.rust.codegen.core.rustlang.Writable
 import software.amazon.smithy.rust.codegen.core.smithy.RustSymbolProvider
+import software.amazon.smithy.rust.codegen.server.smithy.generators.protocol.ServerProtocol
 
 /**
  * Collection of methods that will be invoked by the respective generators to generate code to convert constraint
@@ -26,7 +27,7 @@ interface ValidationExceptionConversionGenerator {
      * Convert from a top-level operation input's constraint violation into
      * `aws_smithy_http_server::rejection::RequestRejection`.
      */
-    fun renderImplFromConstraintViolationForRequestRejection(): Writable
+    fun renderImplFromConstraintViolationForRequestRejection(protocol: ServerProtocol): Writable
 
     // Simple shapes.
     fun stringShapeConstraintViolationImplBlock(stringConstraintsInfo: Collection<StringTraitInfo>): Writable

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocol.kt

@@ -5,7 +5,6 @@
 
 package software.amazon.smithy.rust.codegen.server.smithy.generators.protocol
 
-import software.amazon.smithy.model.knowledge.TopDownIndex
 import software.amazon.smithy.model.shapes.OperationShape
 import software.amazon.smithy.model.shapes.Shape
 import software.amazon.smithy.model.shapes.StructureShape
@@ -37,12 +36,10 @@ import software.amazon.smithy.rust.codegen.server.smithy.protocols.ServerAwsJson
 import software.amazon.smithy.rust.codegen.server.smithy.protocols.ServerRestJsonSerializerGenerator
 import software.amazon.smithy.rust.codegen.server.smithy.targetCanReachConstrainedShape
 
-private fun allOperations(codegenContext: CodegenContext): List<OperationShape> {
-    val index = TopDownIndex.of(codegenContext.model)
-    return index.getContainedOperations(codegenContext.serviceShape).sortedBy { it.id }
-}
-
 interface ServerProtocol : Protocol {
+    /** The path such that `aws_smithy_http_server::proto::$path` points to the protocol's module. */
+    val protocolModulePath: String
+
     /** Returns the Rust marker struct enjoying `OperationShape`. */
     fun markerStruct(): RuntimeType
 
@@ -76,6 +73,21 @@ interface ServerProtocol : Protocol {
      * Returns a boolean indicating whether to perform this check.
      */
     fun serverContentTypeCheckNoModeledInput(): Boolean = false
+
+    /** The protocol-specific `RequestRejection` type. **/
+    fun requestRejection(runtimeConfig: RuntimeConfig): RuntimeType =
+        ServerCargoDependency.smithyHttpServer(runtimeConfig)
+            .toType().resolve("proto::$protocolModulePath::rejection::RequestRejection")
+
+    /** The protocol-specific `ResponseRejection` type. **/
+    fun responseRejection(runtimeConfig: RuntimeConfig): RuntimeType =
+        ServerCargoDependency.smithyHttpServer(runtimeConfig)
+            .toType().resolve("proto::$protocolModulePath::rejection::ResponseRejection")
+
+    /** The protocol-specific `RuntimeError` type. **/
+    fun runtimeError(runtimeConfig: RuntimeConfig): RuntimeType =
+        ServerCargoDependency.smithyHttpServer(runtimeConfig)
+            .toType().resolve("proto::$protocolModulePath::runtime_error::RuntimeError")
 }
 
 class ServerAwsJsonProtocol(
@@ -84,6 +96,12 @@ class ServerAwsJsonProtocol(
 ) : AwsJson(serverCodegenContext, awsJsonVersion), ServerProtocol {
     private val runtimeConfig = codegenContext.runtimeConfig
 
+    override val protocolModulePath: String
+        get() = when (version) {
+            is AwsJsonVersion.Json10 -> "aws_json_10"
+            is AwsJsonVersion.Json11 -> "aws_json_11"
+        }
+
     override fun structuredDataParser(operationShape: OperationShape): StructuredDataParserGenerator {
         fun returnSymbolToParse(shape: Shape): ReturnSymbolToParse =
             if (shape.canReachConstrainedShape(codegenContext.model, serverCodegenContext.symbolProvider)) {
@@ -107,12 +125,8 @@ class ServerAwsJsonProtocol(
 
     override fun markerStruct(): RuntimeType {
         return when (version) {
-            is AwsJsonVersion.Json10 -> {
-                ServerRuntimeType.protocol("AwsJson1_0", "aws_json_10", runtimeConfig)
-            }
-            is AwsJsonVersion.Json11 -> {
-                ServerRuntimeType.protocol("AwsJson1_1", "aws_json_11", runtimeConfig)
-            }
+            is AwsJsonVersion.Json10 -> ServerRuntimeType.protocol("AwsJson1_0", protocolModulePath, runtimeConfig)
+            is AwsJsonVersion.Json11 -> ServerRuntimeType.protocol("AwsJson1_1", protocolModulePath, runtimeConfig)
         }
     }
 
@@ -139,6 +153,16 @@ class ServerAwsJsonProtocol(
         AwsJsonVersion.Json10 -> "new_aws_json_10_router"
         AwsJsonVersion.Json11 -> "new_aws_json_11_router"
     }
+
+    override fun requestRejection(runtimeConfig: RuntimeConfig): RuntimeType =
+        ServerCargoDependency.smithyHttpServer(runtimeConfig)
+            .toType().resolve("proto::aws_json::rejection::RequestRejection")
+    override fun responseRejection(runtimeConfig: RuntimeConfig): RuntimeType =
+        ServerCargoDependency.smithyHttpServer(runtimeConfig)
+            .toType().resolve("proto::aws_json::rejection::ResponseRejection")
+    override fun runtimeError(runtimeConfig: RuntimeConfig): RuntimeType =
+        ServerCargoDependency.smithyHttpServer(runtimeConfig)
+            .toType().resolve("proto::aws_json::runtime_error::RuntimeError")
 }
 
 private fun restRouterType(runtimeConfig: RuntimeConfig) =
@@ -150,6 +174,8 @@ class ServerRestJsonProtocol(
 ) : RestJson(serverCodegenContext), ServerProtocol {
     val runtimeConfig = codegenContext.runtimeConfig
 
+    override val protocolModulePath: String = "rest_json_1"
+
     override fun structuredDataParser(operationShape: OperationShape): StructuredDataParserGenerator {
         fun returnSymbolToParse(shape: Shape): ReturnSymbolToParse =
             if (shape.canReachConstrainedShape(codegenContext.model, codegenContext.symbolProvider)) {
@@ -173,7 +199,7 @@ class ServerRestJsonProtocol(
     override fun structuredDataSerializer(operationShape: OperationShape): StructuredDataSerializerGenerator =
         ServerRestJsonSerializerGenerator(serverCodegenContext, httpBindingResolver)
 
-    override fun markerStruct() = ServerRuntimeType.protocol("RestJson1", "rest_json_1", runtimeConfig)
+    override fun markerStruct() = ServerRuntimeType.protocol("RestJson1", protocolModulePath, runtimeConfig)
 
     override fun routerType() = restRouterType(runtimeConfig)
 
@@ -196,8 +222,9 @@ class ServerRestXmlProtocol(
     codegenContext: CodegenContext,
 ) : RestXml(codegenContext), ServerProtocol {
     val runtimeConfig = codegenContext.runtimeConfig
+    override val protocolModulePath = "rest_xml"
 
-    override fun markerStruct() = ServerRuntimeType.protocol("RestXml", "rest_xml", runtimeConfig)
+    override fun markerStruct() = ServerRuntimeType.protocol("RestXml", protocolModulePath, runtimeConfig)
 
     override fun routerType() = restRouterType(runtimeConfig)