feat: add support for requiresLength trait and Transfer-Encoding: Chunked

Sources/ClientRuntime/Networking/Http/Middlewares/ContentLengthMiddleware.swift

@@ -6,7 +6,14 @@ public struct ContentLengthMiddleware<OperationStackOutput: HttpResponseBinding>
 
     private let contentLengthHeaderName = "Content-Length"
 
-    public init() {}
+    private var requiresLength: Bool = false
+
+    private var unsignedPayload: Bool = false
+
+    public init(requiresLength: Bool = false, unsignedPayload: Bool = false) {
+        self.requiresLength = requiresLength
+        self.unsignedPayload = unsignedPayload
+    }
 
     public func handle<H>(context: Context,
                           input: MInput,
@@ -22,8 +29,12 @@ public struct ContentLengthMiddleware<OperationStackOutput: HttpResponseBinding>
         case .stream(let stream):
             if let length = stream.length {
                 input.headers.update(name: "Content-Length", value: String(length))
+            } else if !requiresLength && unsignedPayload {
+                // only for HTTP/1.1 requests, will be removed in all HTTP/2 requests
+                input.headers.update(name: "Transfer-Encoding", value: "Chunked")
             } else {
-                input.headers.update(name: "Transfer-Encoded", value: "Chunked")
+                let errorMessage = unsignedPayload ? "operation requires length" : "sigv4 requires length"
+                throw StreamError.notSupported(errorMessage)
             }
         default:
             input.headers.update(name: "Content-Length", value: "0")

Sources/ClientRuntime/Networking/Http/SdkHttpRequest.swift

@@ -75,6 +75,9 @@ extension SdkHttpRequest {
         httpRequest.path = [endpoint.path, endpoint.queryItemString].compactMap { $0 }.joined(separator: "?")
         httpRequest.addHeaders(headers: headers.toHttpHeaders())
 
+        // Remove the "Transfer-Encoding" header if it exists since h2 does not support it
+        httpRequest.removeHeader(name: "Transfer-Encoding")
+
         // HTTP2Request used with manual writes hence we need to set the body to nil
         // so that CRT does not write the body for us (we will write it manually)
         httpRequest.body = nil

Tests/ClientRuntimeTests/NetworkingTests/ContentLengthMiddlewareTests.swift

@@ -0,0 +1,85 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0.
+
+import XCTest
+import SmithyTestUtil
+@testable import ClientRuntime
+
+class ContentLengthMiddlewareTests: XCTestCase {
+    private var builtContext: HttpContext!
+    private var stack: OperationStack<MockInput, MockOutput, MockMiddlewareError>!
+
+    override func setUpWithError() throws {
+        try super.setUpWithError()
+        builtContext = HttpContextBuilder()
+                  .withMethod(value: .get)
+                  .withPath(value: "/")
+                  .withEncoder(value: JSONEncoder())
+                  .withDecoder(value: JSONDecoder())
+                  .withOperation(value: "Test Operation")
+                  .build()
+        stack = OperationStack<MockInput, MockOutput, MockMiddlewareError>(id: "Test Operation")
+    }
+
+    func testTransferEncodingChunkedSetWhenStreamLengthIsNil() async throws {
+        addContentLengthMiddlewareWith(requiresLength: false, unsignedPayload: true)
+        forceEmptyStream()
+        try await AssertHeadersArePresent(expectedHeaders: ["Transfer-Encoding": "Chunked"])
+    }
+
+    func testContentLengthSetWhenStreamLengthAvailableAndRequiresLengthSet() async throws {
+        addContentLengthMiddlewareWith(requiresLength: true, unsignedPayload: false)
+        try await AssertHeadersArePresent(expectedHeaders: ["Content-Length": "0"])
+    }
+
+    func testContentLengthSetWhenRequiresLengthAndUnsignedPayload() async throws {
+        addContentLengthMiddlewareWith(requiresLength: true, unsignedPayload: true)
+        try await AssertHeadersArePresent(expectedHeaders: ["Content-Length": "0"])
+    }
+
+    func testRequiresLengthSetWithNilStreamShouldThrowError() async throws {
+        addContentLengthMiddlewareWith(requiresLength: true, unsignedPayload: false)
+        forceEmptyStream()
+        do {
+            try await AssertHeadersArePresent(expectedHeaders: ["Content-Length": "0"])
+            XCTFail("Should throw error")
+        } catch let error as StreamError {
+            switch error {
+            case .notSupported("sigv4 requires length"), .notSupported("operation requires length"):
+                // The error matches one of the expected cases, test passes
+                break
+            default:
+                XCTFail("Error is not StreamError.notSupported with expected message")
+            }
+        }
+    }
+
+    private func addContentLengthMiddlewareWith(requiresLength: Bool, unsignedPayload: Bool) {
+        stack.finalizeStep.intercept(
+            position: .before,
+            middleware: ContentLengthMiddleware(requiresLength: requiresLength, unsignedPayload: unsignedPayload)
+        )
+    }
+
+    private func forceEmptyStream() {
+        // Force stream length to be nil
+        stack.finalizeStep.intercept(position: .before, id: "set nil stream length") { (context, input, next) -> OperationOutput<MockOutput> in
+            input.body = .stream(BufferedStream()) // Set the stream length to nil
+            return try await next.handle(context: context, input: input)
+        }
+    }
+
+    private func AssertHeadersArePresent(expectedHeaders: [String: String], file: StaticString = #file, line: UInt = #line) async throws -> Void {
+        _ = try await stack.handleMiddleware(context: builtContext, input: MockInput(),
+                                              next: MockHandler(handleCallback: { (_, input) in
+                                                  for (key, value) in expectedHeaders {
+                                                      XCTAssert(input.headers.value(for: key) == value, file: file, line: line)
+                                                  }
+                                                  let httpResponse = HttpResponse(body: HttpBody.none, statusCode: HttpStatusCode.ok)
+                                                  let mockOutput = try! MockOutput(httpResponse: httpResponse, decoder: nil)
+                                                  let output = OperationOutput<MockOutput>(httpResponse: httpResponse,
+                                                                                           output: mockOutput)
+                                                  return output
+                                              }))
+    }
+}

smithy-swift-codegen/src/main/kotlin/software/amazon/smithy/swift/codegen/integration/HttpBindingProtocolGenerator.kt

@@ -4,6 +4,7 @@
  */
 package software.amazon.smithy.swift.codegen.integration
 
+import software.amazon.smithy.aws.traits.auth.UnsignedPayloadTrait
 import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.model.knowledge.HttpBinding
 import software.amazon.smithy.model.knowledge.HttpBindingIndex
@@ -30,6 +31,7 @@ import software.amazon.smithy.model.traits.HttpPrefixHeadersTrait
 import software.amazon.smithy.model.traits.HttpQueryParamsTrait
 import software.amazon.smithy.model.traits.HttpQueryTrait
 import software.amazon.smithy.model.traits.MediaTypeTrait
+import software.amazon.smithy.model.traits.RequiresLengthTrait
 import software.amazon.smithy.model.traits.StreamingTrait
 import software.amazon.smithy.model.traits.TimestampFormatTrait
 import software.amazon.smithy.swift.codegen.ClientRuntimeTypes
@@ -60,6 +62,7 @@ import software.amazon.smithy.swift.codegen.integration.serde.UnionEncodeGenerat
 import software.amazon.smithy.swift.codegen.middleware.OperationMiddlewareGenerator
 import software.amazon.smithy.swift.codegen.model.ShapeMetadata
 import software.amazon.smithy.swift.codegen.model.bodySymbol
+import software.amazon.smithy.swift.codegen.model.findStreamingMember
 import software.amazon.smithy.swift.codegen.model.hasEventStreamMember
 import software.amazon.smithy.swift.codegen.model.hasTrait
 import software.amazon.smithy.utils.OptionalUtils
@@ -91,9 +94,8 @@ fun formatHeaderOrQueryValue(
     memberShape: MemberShape,
     location: HttpBinding.Location,
     bindingIndex: HttpBindingIndex,
-    defaultTimestampFormat: TimestampFormatTrait.Format
+    defaultTimestampFormat: TimestampFormatTrait.Format,
 ): Pair<String, Boolean> {
-
     return when (val shape = ctx.model.expectShape(memberShape.target)) {
         is TimestampShape -> {
             val timestampFormat = bindingIndex.determineTimestampFormat(memberShape, location, defaultTimestampFormat)
@@ -165,7 +167,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                     writer.openBlock(
                         "extension $symbolName: \$N {",
                         "}",
-                        SwiftTypes.Protocols.Encodable
+                        SwiftTypes.Protocols.Encodable,
                     ) {
                         writer.addImport(SwiftDependency.CLIENT_RUNTIME.target)
 
@@ -286,7 +288,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
     private fun generateCodingKeysForMembers(
         ctx: ProtocolGenerator.GenerationContext,
         writer: SwiftWriter,
-        members: List<MemberShape>
+        members: List<MemberShape>,
     ) {
         codingKeysGenerator.generateCodingKeysForMembers(ctx, writer, members)
     }
@@ -298,7 +300,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
             val inputType = ctx.model.expectShape(operation.input.get())
             var metadata = mapOf<ShapeMetadata, Any>(
                 Pair(ShapeMetadata.OPERATION_SHAPE, operation),
-                Pair(ShapeMetadata.SERVICE_VERSION, ctx.service.version)
+                Pair(ShapeMetadata.SERVICE_VERSION, ctx.service.version),
             )
             shapesInfo.put(inputType, metadata)
         }
@@ -336,7 +338,6 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
     }
 
     private fun resolveShapesNeedingCodableConformance(ctx: ProtocolGenerator.GenerationContext): Set<Shape> {
-
         val topLevelOutputMembers = getHttpBindingOperations(ctx).flatMap {
             val outputShape = ctx.model.expectShape(it.output.get())
             outputShape.members()
@@ -390,7 +391,8 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                     RelationshipType.LIST_MEMBER,
                     RelationshipType.SET_MEMBER,
                     RelationshipType.MAP_VALUE,
-                    RelationshipType.UNION_MEMBER -> true
+                    RelationshipType.UNION_MEMBER,
+                    -> true
                     else -> false
                 }
             }.forEach {
@@ -403,6 +405,31 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
         return resolved
     }
 
+    // Checks for @requiresLength trait
+    // Returns true if the operation:
+    // - has a streaming member with @httpPayload trait
+    // - target is a blob shape with @requiresLength trait
+    private fun hasRequiresLengthTrait(ctx: ProtocolGenerator.GenerationContext, op: OperationShape): Boolean {
+        if (op.input.isPresent) {
+            val inputShape = ctx.model.expectShape(op.input.get())
+            val streamingMember = inputShape.findStreamingMember(ctx.model)
+            if (streamingMember != null) {
+                val targetShape = ctx.model.expectShape(streamingMember.target)
+                if (targetShape != null) {
+                    return streamingMember.hasTrait<HttpPayloadTrait>() &&
+                        targetShape.isBlobShape &&
+                        targetShape.hasTrait<RequiresLengthTrait>()
+                }
+            }
+        }
+        return false
+    }
+
+    // Checks for @unsignedPayload trait on an operation
+    private fun hasUnsignedBody(op: OperationShape): Boolean {
+        return op.hasTrait<UnsignedPayloadTrait>()
+    }
+
     override fun generateProtocolClient(ctx: ProtocolGenerator.GenerationContext) {
         val symbol = ctx.symbolProvider.toSymbol(ctx.service)
         ctx.delegator.useFileWriter("./${ctx.settings.moduleName}/${symbol.name}.swift") { writer ->
@@ -414,7 +441,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                 serviceSymbol.name,
                 defaultContentType,
                 httpProtocolCustomizable,
-                operationMiddleware
+                operationMiddleware,
             )
             clientGenerator.render()
         }
@@ -433,7 +460,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
             operationMiddleware.appendMiddleware(operation, ContentTypeMiddleware(ctx.model, ctx.symbolProvider, resolver.determineRequestContentType(operation)))
             operationMiddleware.appendMiddleware(operation, OperationInputBodyMiddleware(ctx.model, ctx.symbolProvider))
 
-            operationMiddleware.appendMiddleware(operation, ContentLengthMiddleware(ctx.model, shouldRenderEncodableConformance))
+            operationMiddleware.appendMiddleware(operation, ContentLengthMiddleware(ctx.model, shouldRenderEncodableConformance, hasRequiresLengthTrait(ctx, operation), hasUnsignedBody(operation)))
 
             operationMiddleware.appendMiddleware(operation, DeserializeMiddleware(ctx.model, ctx.symbolProvider))
             operationMiddleware.appendMiddleware(operation, LoggingMiddleware(ctx.model, ctx.symbolProvider))
@@ -463,15 +490,15 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
         members: List<MemberShape>,
         writer: SwiftWriter,
         defaultTimestampFormat: TimestampFormatTrait.Format,
-        path: String? = null
+        path: String? = null,
     )
     protected abstract fun renderStructDecode(
         ctx: ProtocolGenerator.GenerationContext,
         shapeMetaData: Map<ShapeMetadata, Any>,
         members: List<MemberShape>,
         writer: SwiftWriter,
         defaultTimestampFormat: TimestampFormatTrait.Format,
-        path: String
+        path: String,
     )
     protected abstract fun addProtocolSpecificMiddleware(ctx: ProtocolGenerator.GenerationContext, operation: OperationShape)
 
@@ -487,11 +514,11 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
         for (operation in topDownIndex.getContainedOperations(ctx.service)) {
             OptionalUtils.ifPresentOrElse(
                 Optional.of(getProtocolHttpBindingResolver(ctx, defaultContentType).httpTrait(operation)::class.java),
-                { containedOperations.add(operation) }
+                { containedOperations.add(operation) },
             ) {
                 LOGGER.warning(
                     "Unable to fetch $protocolName protocol request bindings for ${operation.id} because " +
-                        "it does not have an http binding trait"
+                        "it does not have an http binding trait",
                 )
             }
         }

smithy-swift-codegen/src/main/kotlin/software/amazon/smithy/swift/codegen/integration/middlewares/ContentLengthMiddleware.kt

@@ -9,7 +9,7 @@ import software.amazon.smithy.swift.codegen.middleware.MiddlewarePosition
 import software.amazon.smithy.swift.codegen.middleware.MiddlewareRenderable
 import software.amazon.smithy.swift.codegen.middleware.MiddlewareStep
 
-class ContentLengthMiddleware(val model: Model, private val alwaysIntercept: Boolean) : MiddlewareRenderable {
+class ContentLengthMiddleware(val model: Model, private val alwaysIntercept: Boolean, private val requiresLength: Boolean, private val unsignedPayload: Boolean) : MiddlewareRenderable {
 
     override val name = "ContentLengthMiddleware"
 
@@ -20,17 +20,20 @@ class ContentLengthMiddleware(val model: Model, private val alwaysIntercept: Boo
     override fun render(
         writer: SwiftWriter,
         op: OperationShape,
-        operationStackName: String
+        operationStackName: String,
     ) {
         val hasHttpBody = MiddlewareShapeUtils.hasHttpBody(model, op)
         if (hasHttpBody || alwaysIntercept) {
-            writer.write(
-                "\$L.\$L.intercept(position: \$L, middleware: \$N())",
-                operationStackName,
-                middlewareStep.stringValue(),
-                position.stringValue(),
-                ClientRuntimeTypes.Middleware.ContentLengthMiddleware
-            )
+            val middlewareArgs = if (requiresLength || unsignedPayload) {
+                "requiresLength: $requiresLength, unsignedPayload: $unsignedPayload"
+            } else {
+                ""
+            }
+
+            val interceptStatement = "$operationStackName.${middlewareStep.stringValue()}.intercept(" +
+                "position: ${position.stringValue()}, middleware: ${ClientRuntimeTypes.Middleware.ContentLengthMiddleware}($middlewareArgs))"
+
+            writer.write(interceptStatement)
         }
     }
 }

smithy-swift-codegen/src/test/kotlin/HttpBindingProtocolGeneratorTests.kt

@@ -38,7 +38,7 @@ class TestHttpProtocolClientGeneratorFactory : HttpProtocolClientGeneratorFactor
     private fun getClientProperties(ctx: ProtocolGenerator.GenerationContext): List<ClientProperty> {
         return mutableListOf(
             DefaultRequestEncoder(),
-            DefaultResponseDecoder()
+            DefaultResponseDecoder(),
         )
     }
 
@@ -125,6 +125,7 @@ extension InlineDocumentAsPayloadOutput: ClientRuntime.HttpResponseBinding {
             """.trimIndent()
         contents.shouldContainOnlyOnce(expectedContents)
     }
+
     @Test
     fun `default fooMap to an empty map if keysForFooMap is empty`() {
         val contents = getModelFileContents("example", "HttpPrefixHeadersOutput+HttpResponseBinding.swift", newTestContext.manifest)