split out some files and clean up error handling in foundation client

AmplifyPlugins/Core/AWSPluginsCore/Utils/CustomHttpClientEngine/ClientRuntimeFoundationBridge.swift

@@ -0,0 +1,64 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Foundation
+import ClientRuntime
+
+extension Foundation.URLRequest {
+    init(sdkRequest: ClientRuntime.SdkHttpRequest) throws {
+        guard let url = sdkRequest.endpoint.url else {
+            throw FoundationHTTPClientError.invalidRequestURL(sdkRequest: sdkRequest)
+        }
+        self.init(url: url)
+        httpMethod = sdkRequest.method.rawValue
+
+        for header in sdkRequest.headers.headers {
+            for value in header.value {
+                addValue(value, forHTTPHeaderField: header.name)
+            }
+        }
+
+        switch sdkRequest.body {
+        case .data(let data): httpBody = data
+        case .stream(let stream): httpBody = stream.toBytes().getData()
+        case .none: break
+        }
+    }
+}
+
+extension ClientRuntime.HttpResponse {
+    private static func headers(
+        from allHeaderFields: [AnyHashable: Any]
+    ) -> ClientRuntime.Headers {
+        var headers = Headers()
+        for header in allHeaderFields {
+            switch (header.key, header.value) {
+            case let (key, value) as (String, String):
+                headers.add(name: key, value: value)
+            case let (key, values) as (String, [String]):
+                headers.add(name: key, values: values)
+            default: continue
+            }
+        }
+        return headers
+    }
+
+    convenience init(httpURLResponse: HTTPURLResponse, data: Data) throws {
+        let headers = Self.headers(from: httpURLResponse.allHeaderFields)
+        let body = HttpBody.stream(ByteStream.from(data: data))
+
+        guard let statusCode = HttpStatusCode(rawValue: httpURLResponse.statusCode) else {
+            // This shouldn't happen, but `HttpStatusCode` only exposes a failable
+            // `init`. The alternative here is force unwrapping, but we can't
+            // make the decision to crash here on behalf on consuming applications.
+            throw FoundationHTTPClientError.unexpectedStatusCode(
+                statusCode: httpURLResponse.statusCode
+            )
+        }
+        self.init(headers: headers, body: body, statusCode: statusCode)
+    }
+}

AmplifyPlugins/Core/AWSPluginsCore/Utils/CustomHttpClientEngine/FoundationHTTPClientEngine+Error.swift

@@ -0,0 +1,81 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Foundation
+import Amplify
+import ClientRuntime
+
+struct FoundationHTTPClientError: AmplifyError {
+    let errorDescription: ErrorDescription
+    let recoverySuggestion: RecoverySuggestion
+    let underlyingError: Error?
+
+    // protocol requirement
+    init(
+        errorDescription: ErrorDescription,
+        recoverySuggestion: RecoverySuggestion,
+        error: Error
+    ) {
+        self.errorDescription = errorDescription
+        self.recoverySuggestion = recoverySuggestion
+        self.underlyingError = error
+    }
+}
+
+extension FoundationHTTPClientError {
+    init(
+        errorDescription: ErrorDescription,
+        recoverySuggestion: RecoverySuggestion,
+        error: Error?
+    ) {
+        self.errorDescription = errorDescription
+        self.recoverySuggestion = recoverySuggestion
+        self.underlyingError = error
+    }
+
+    static func invalidRequestURL(sdkRequest: ClientRuntime.SdkHttpRequest) -> Self {
+        .init(
+            errorDescription: """
+            The SdkHttpRequest generated by ClientRuntime doesn't include a valid URL
+            - \(sdkRequest)
+            """,
+            recoverySuggestion: """
+            Please open an issue at https://github.com/aws-amplify/amplify-swift
+            with the contents of this error message.
+            """,
+            error: nil
+        )
+    }
+
+    static func invalidURLResponse(urlRequest: URLResponse) -> Self {
+        .init(
+            errorDescription: """
+            The URLResponse received is not an HTTPURLResponse
+            - \(urlRequest)
+            """,
+            recoverySuggestion: """
+            Please open an issue at https://github.com/aws-amplify/amplify-swift
+            with the contents of this error message.
+            """,
+            error: nil
+        )
+    }
+
+    static func unexpectedStatusCode(statusCode: Int) -> Self {
+        .init(
+            errorDescription: """
+            The status code received isn't a valid `HttpStatusCode` value.
+            - status code: \(statusCode)
+            """,
+            recoverySuggestion: """
+            Please open an issue at https://github.com/aws-amplify/amplify-swift
+            with the contents of this error message.
+            """,
+            error: nil
+        )
+    }
+}

AmplifyPlugins/Core/AWSPluginsCore/Utils/CustomHttpClientEngine/FoundationHTTPClientEngine.swift

@@ -9,93 +9,18 @@ import Foundation
 import ClientRuntime
 import Amplify
 
-struct InvalidRequestURL: AmplifyError {
-    let errorDescription: ErrorDescription
-    let recoverySuggestion: RecoverySuggestion
-    let underlyingError: Error?
-
-    init(sdkRequest: ClientRuntime.SdkHttpRequest) {
-        self.errorDescription = """
-        The SdkHttpRequest generated by ClientRuntime doesn't include a valid URL
-        - \(sdkRequest)
-        """
-        self.recoverySuggestion = """
-        Please open an issue at https://github.com/aws-amplify/amplify-swift
-        with the contents of this error message.
-        """
-        self.underlyingError = nil
-    }
-
-    // Protocol requirement
-    init(
-        errorDescription: ErrorDescription,
-        recoverySuggestion: RecoverySuggestion,
-        error: Error
-    ) {
-        self.errorDescription = errorDescription
-        self.recoverySuggestion = recoverySuggestion
-        self.underlyingError = error
-    }
-}
-
-extension Foundation.URLRequest {
-    init(sdkRequest: ClientRuntime.SdkHttpRequest) throws {
-        guard let url = sdkRequest.endpoint.url else {
-            throw InvalidRequestURL(sdkRequest: sdkRequest)
-        }
-        self.init(url: url)
-        httpMethod = sdkRequest.method.rawValue
-
-        for header in sdkRequest.headers.headers {
-            for value in header.value {
-                addValue(value, forHTTPHeaderField: header.name)
-            }
-        }
-
-        switch sdkRequest.body {
-        case .data(let data): httpBody = data
-        case .stream(let stream): httpBody = stream.toBytes().getData()
-        case .none: break
-        }
-    }
-}
-
-extension ClientRuntime.HttpResponse {
-    private static func headers(
-        from allHeaderFields: [AnyHashable: Any]
-    ) -> ClientRuntime.Headers {
-        var headers = Headers()
-        for header in allHeaderFields {
-            switch (header.key, header.value) {
-            case let (key, value) as (String, String):
-                headers.add(name: key, value: value)
-            case let (key, values) as (String, [String]):
-                headers.add(name: key, values: values)
-            default: continue
-            }
-        }
-        return headers
-    }
-
-    convenience init(httpURLResponse: HTTPURLResponse, data: Data) {
-        let headers = Self.headers(from: httpURLResponse.allHeaderFields)
-        let body = HttpBody.stream(ByteStream.from(data: data))
-        // fix force unwrap
-        let statusCode = HttpStatusCode(rawValue: httpURLResponse.statusCode)!
-        self.init(headers: headers, body: body, statusCode: statusCode)
-    }
-}
-
 @_spi(FoundationHTTPClientEngine)
 public struct FoundationHTTPClient: HttpClientEngine {
     public func execute(request: ClientRuntime.SdkHttpRequest) async throws -> ClientRuntime.HttpResponse {
         let urlRequest = try URLRequest(sdkRequest: request)
 
         let (data, response) = try await URLSession.shared.data(for: urlRequest)
-        // Quinn says it's ok to do this.
-        // Safely Force Downcasting a URLResponse to an HTTPURLResponse -
-        // https://developer.apple.com/forums/thread/120099?answerId=372749022#372749022
-        let httpURLResponse = response as! HTTPURLResponse
+        guard let httpURLResponse = response as? HTTPURLResponse else {
+            // This shouldn't be necessary because we're only making HTTP requests.
+            // `URLResponse` should always be a `HTTPURLResponse`.
+            // But to refrain from crashing consuming applications, we're throwing here.
+            throw FoundationHTTPClientError.invalidURLResponse(urlRequest: response)
+        }
 
         let httpResponse = HttpResponse(
             httpURLResponse: httpURLResponse,