feat: Add Swift 6 language mode support (#920)

Author: dayaffe

.github/workflows/swift6-compatibility.yml

@@ -0,0 +1,34 @@
+name: Swift6 Compatibility
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+  workflow_dispatch:
+
+env:
+  AWS_SWIFT_SDK_USE_LOCAL_DEPS: 1
+
+jobs:
+  bump-swift-tools-version:
+    if: github.repository == 'smithy-lang/smithy-swift' || github.event_name == 'pull_request'
+    runs-on: ${{ matrix.runner }}
+    strategy:
+      fail-fast: false
+      matrix:
+        runner:
+          - macos-15
+        xcode:
+          - Xcode_16.1
+        destination:
+          - 'platform=macOS'
+    steps:
+      - name: Checkout smithy-swift
+        uses: actions/checkout@v4
+      - name: Setup common tools
+        uses: ./.github/actions/setup-common-tools-composite-action
+      - name: Build on swift-tools-version 6.0
+        run: |
+          perl -pi -e 's{^// swift-tools-version:\d+\.\d+}{// swift-tools-version:6.0}' Package.swift
+          set -euo pipefail
+          swift build

Package.swift

@@ -56,7 +56,7 @@ let package = Package(
     ],
     dependencies: {
         var dependencies: [Package.Dependency] = [
-            .package(url: "https://github.com/awslabs/aws-crt-swift.git", exact: "0.48.0"),
+            .package(url: "https://github.com/awslabs/aws-crt-swift.git", exact: "0.52.1"),
             .package(url: "https://github.com/apple/swift-log.git", from: "1.0.0"),
         ]
         let isDocCEnabled = ProcessInfo.processInfo.environment["AWS_SWIFT_SDK_ENABLE_DOCC"] != nil
@@ -157,7 +157,10 @@ let package = Package(
         ),
         .target(
             name: "SmithyHTTPAPI",
-            dependencies: ["Smithy"]
+            dependencies: [
+                "Smithy",
+                .product(name: "AwsCommonRuntimeKit", package: "aws-crt-swift")
+            ]
         ),
         .target(
             name: "SmithyHTTPClient",

Sources/ClientRuntime/Config/DefaultSDKRuntimeConfiguration.swift

@@ -131,7 +131,7 @@ public class DefaultAuthSchemeResolverParameters: AuthSchemeResolverParameters {
     }
 }
 
-public class DefaultAuthSchemeResolver: AuthSchemeResolver {
+public final class DefaultAuthSchemeResolver: AuthSchemeResolver, Sendable {
     public func resolveAuthScheme(params: AuthSchemeResolverParameters) throws -> [AuthOption] {
         return []
     }

Sources/ClientRuntime/Config/IdempotencyTokenGenerator.swift

@@ -3,6 +3,6 @@
  * SPDX-License-Identifier: Apache-2.0.
  */
 
-public protocol IdempotencyTokenGenerator {
+public protocol IdempotencyTokenGenerator: Sendable {
     func generateToken() -> String
 }

Sources/ClientRuntime/Endpoints/CRTResolvedEndpoint.swift

@@ -34,7 +34,7 @@ public class CRTResolvedEndpoint {
         }
     }
 
-    public func getProperties() -> [String: AnyHashable]? {
+    public func getProperties() -> [String: EndpointProperty]? {
         switch crtResolvedEndpoint {
         case let .endpoint(_, _, properties):
             return properties

Sources/ClientRuntime/Endpoints/DefaultEndpointResolver.swift

@@ -7,6 +7,7 @@
 
 import struct SmithyHTTPAPI.Endpoint
 import struct SmithyHTTPAPI.Headers
+import enum SmithyHTTPAPI.EndpointPropertyValue
 
 public struct DefaultEndpointResolver<Params: EndpointsRequestContextProviding> {
 
@@ -32,6 +33,6 @@ public struct DefaultEndpointResolver<Params: EndpointsRequestContextProviding>
 
         let headers = crtResolvedEndpoint.getHeaders() ?? [:]
         let properties = crtResolvedEndpoint.getProperties() ?? [:]
-        return try Endpoint(urlString: url, headers: Headers(headers), properties: properties)
+        return try Endpoint(urlString: url, headers: Headers(headers), endpointProperties: properties)
     }
 }

Sources/ClientRuntime/Endpoints/EndpointsAuthSchemeResolver.swift

@@ -5,6 +5,8 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
+import enum SmithyHTTPAPI.EndpointPropertyValue
+
 /// Supported authentication schemes
 public enum EndpointsAuthScheme: Equatable {
     case sigV4(SigV4Parameters)
@@ -25,7 +27,8 @@ extension EndpointsAuthScheme {
     /// Initialize an AuthScheme from a dictionary
     /// - Parameter dictionary: Dictionary containing the auth scheme
     public init(from dictionary: [String: Any]) throws {
-        guard let name = dictionary["name"] as? String else {
+        guard let endpointProperty = dictionary["name"] as? SmithyHTTPAPI.EndpointPropertyValue,
+              case let .string(name) = endpointProperty else {
             throw EndpointError.authScheme("Invalid auth scheme")
         }
         switch name {
@@ -60,9 +63,29 @@ extension EndpointsAuthScheme.SigV4Parameters {
     /// Initialize a SigV4AuthScheme from a dictionary
     /// - Parameter dictionary: Dictionary containing the auth scheme
     init(from dictionary: [String: Any]) throws {
-        self.signingName = dictionary["signingName"] as? String
-        self.signingRegion = dictionary["signingRegion"] as? String
-        self.disableDoubleEncoding = dictionary["disableDoubleEncoding"] as? Bool
+        // For signingName (expected to be a string)
+        if let value = dictionary["signingName"] as? EndpointPropertyValue,
+           case let .string(name) = value {
+            self.signingName = name
+        } else {
+            self.signingName = nil
+        }
+
+        // For signingRegion (expected to be a string)
+        if let value = dictionary["signingRegion"] as? EndpointPropertyValue,
+           case let .string(region) = value {
+            self.signingRegion = region
+        } else {
+            self.signingRegion = nil
+        }
+
+        // For disableDoubleEncoding (expected to be a bool)
+        if let value = dictionary["disableDoubleEncoding"] as? EndpointPropertyValue,
+           case let .bool(flag) = value {
+            self.disableDoubleEncoding = flag
+        } else {
+            self.disableDoubleEncoding = nil
+        }
     }
 }
 
@@ -86,9 +109,34 @@ extension EndpointsAuthScheme.SigV4AParameters {
     /// Initialize a SigV4AAuthScheme from a dictionary
     /// - Parameter dictionary: Dictionary containing the auth scheme
     init(from dictionary: [String: Any]) throws {
-        self.signingName = dictionary["signingName"] as? String
-        self.signingRegionSet = dictionary["signingRegionSet"] as? [String]
-        self.disableDoubleEncoding = dictionary["disableDoubleEncoding"] as? Bool
+        // Extract signingName
+        if let value = dictionary["signingName"] as? EndpointPropertyValue,
+           case let .string(name) = value {
+            self.signingName = name
+        } else {
+            self.signingName = nil
+        }
+
+        // Extract signingRegionSet as an array of String
+        if let value = dictionary["signingRegionSet"] as? EndpointPropertyValue,
+           case let .array(regions) = value {
+            self.signingRegionSet = regions.compactMap { element in
+                if case let .string(region) = element {
+                    return region
+                }
+                return nil
+            }
+        } else {
+            self.signingRegionSet = nil
+        }
+
+        // Extract disableDoubleEncoding
+        if let value = dictionary["disableDoubleEncoding"] as? EndpointPropertyValue,
+           case let .bool(flag) = value {
+            self.disableDoubleEncoding = flag
+        } else {
+            self.disableDoubleEncoding = nil
+        }
     }
 }