Add concurrency tests

Author: Econa77

APIKit.xcodeproj/project.pbxproj

@@ -48,6 +48,7 @@
 		7F7048F31D9D8A1F003C99F6 /* URLEncodedSerialization.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7F7048F21D9D8A1F003C99F6 /* URLEncodedSerialization.swift */; };
 		7FA1690D1D9D8C80006C982B /* HTTPStub.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7FA1690C1D9D8C80006C982B /* HTTPStub.swift */; };
 		C5725F4B28D8C36500810D7C /* Concurrency.swift in Sources */ = {isa = PBXBuildFile; fileRef = C5725F4A28D8C36500810D7C /* Concurrency.swift */; };
+		C5B144D828D8D7DC00E30ECD /* ConcurrencyTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C5B144D728D8D7DC00E30ECD /* ConcurrencyTests.swift */; };
 		C5FF1DC128A80FFD0059573D /* test.json in Resources */ = {isa = PBXBuildFile; fileRef = C5FF1DC028A80FFD0059573D /* test.json */; };
 		ECA831481DE4DDBF004EB1B5 /* ProtobufDataParser.swift in Sources */ = {isa = PBXBuildFile; fileRef = ECA831471DE4DDBF004EB1B5 /* ProtobufDataParser.swift */; };
 		ECA8314A1DE4DEBE004EB1B5 /* ProtobufDataParserTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = ECA831491DE4DEBE004EB1B5 /* ProtobufDataParserTests.swift */; };
@@ -130,6 +131,7 @@
 		7F8ECDFD1B6A799E00234E04 /* Demo.playground */ = {isa = PBXFileReference; lastKnownFileType = file.playground; path = Demo.playground; sourceTree = "<group>"; xcLanguageSpecificationIdentifier = xcode.lang.swift; };
 		7FA1690C1D9D8C80006C982B /* HTTPStub.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = HTTPStub.swift; sourceTree = "<group>"; };
 		C5725F4A28D8C36500810D7C /* Concurrency.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Concurrency.swift; sourceTree = "<group>"; };
+		C5B144D728D8D7DC00E30ECD /* ConcurrencyTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ConcurrencyTests.swift; sourceTree = "<group>"; };
 		C5FF1DC028A80FFD0059573D /* test.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; path = test.json; sourceTree = "<group>"; };
 		ECA831471DE4DDBF004EB1B5 /* ProtobufDataParser.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = ProtobufDataParser.swift; path = Sources/APIKit/DataParser/ProtobufDataParser.swift; sourceTree = SOURCE_ROOT; };
 		ECA831491DE4DEBE004EB1B5 /* ProtobufDataParserTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ProtobufDataParserTests.swift; sourceTree = "<group>"; };
@@ -242,6 +244,7 @@
 				7F698E451D9D680C00F1561D /* RequestTests.swift */,
 				7F698E491D9D680C00F1561D /* SessionCallbackQueueTests.swift */,
 				7F698E4A1D9D680C00F1561D /* SessionTests.swift */,
+				C5B144D628D8D7D000E30ECD /* Concurrency */,
 				0973EE33259E2DD000879BA2 /* Combine */,
 				7F698E3B1D9D680C00F1561D /* BodyParametersType */,
 				7F698E401D9D680C00F1561D /* DataParserType */,
@@ -376,6 +379,14 @@
 			path = APIKit/Concurrency;
 			sourceTree = "<group>";
 		};
+		C5B144D628D8D7D000E30ECD /* Concurrency */ = {
+			isa = PBXGroup;
+			children = (
+				C5B144D728D8D7DC00E30ECD /* ConcurrencyTests.swift */,
+			);
+			path = Concurrency;
+			sourceTree = "<group>";
+		};
 		C5FF1DBF28A80FFD0059573D /* Resources */ = {
 			isa = PBXGroup;
 			children = (
@@ -534,6 +545,7 @@
 				7F698E581D9D680C00F1561D /* RequestTests.swift in Sources */,
 				ECA8314A1DE4DEBE004EB1B5 /* ProtobufDataParserTests.swift in Sources */,
 				7F698E5E1D9D680C00F1561D /* TestRequest.swift in Sources */,
+				C5B144D828D8D7DC00E30ECD /* ConcurrencyTests.swift in Sources */,
 				7F698E601D9D680C00F1561D /* TestSessionTask.swift in Sources */,
 				0973EE35259E2DDC00879BA2 /* CombineTests.swift in Sources */,
 				7FA1690D1D9D8C80006C982B /* HTTPStub.swift in Sources */,

Sources/APIKit/Combine/Combine.swift

@@ -68,6 +68,7 @@ public struct SessionTaskPublisher<Request: APIKit.Request>: Publisher {
 @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
 public extension Session {
     /// Calls `sessionTaskPublisher(for:callbackQueue:)` of `Session.shared`.
+    /// 
     /// - parameter request: The request to be sent.
     /// - parameter callbackQueue: The queue where the handler runs. If this parameters is `nil`, default `callbackQueue` of `Session` will be used.
     /// - returns: A publisher that wraps a session task for the request.

Sources/APIKit/Concurrency/Concurrency.swift

@@ -4,22 +4,31 @@ import Foundation
 
 @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
 public extension Session {
+    /// Calls `response(for:callbackQueue:)` of `Session.shared`.
+    ///
+    /// - parameter request: The request to be sent.
+    /// - parameter callbackQueue: The queue where the handler runs. If this parameters is `nil`, default `callbackQueue` of `Session` will be used.
+    /// - returns: `Request.Response`
     static func response<Request: APIKit.Request>(for request: Request, callbackQueue: CallbackQueue? = nil) async throws -> Request.Response {
         return try await shared.response(for: request, callbackQueue: callbackQueue)
     }
 
+    /// Convenience method to load `Request.Response` using an `Request`, creates and resumes an `SessionTask` internally.
+    ///
+    /// - parameter request: The request to be sent.
+    /// - parameter callbackQueue: The queue where the handler runs. If this parameters is `nil`, default `callbackQueue` of `Session` will be used.
+    /// - returns: `Request.Response`
     func response<Request: APIKit.Request>(for request: Request, callbackQueue: CallbackQueue? = nil) async throws -> Request.Response {
         let cancellationHandler = SessionTaskCancellationHandler()
         return try await withTaskCancellationHandler(operation: {
-            return try await withUnsafeThrowingContinuation { continuation in
+            return try await withCheckedThrowingContinuation { continuation in
+                guard !Task.isCancelled else {
+                    continuation.resume(throwing: SessionTaskError.taskAlreadyCancelledError)
+                    return
+                }
                 Task {
                     let sessionTask = send(request, callbackQueue: callbackQueue) { result in
-                        switch result {
-                        case .success(let response):
-                            continuation.resume(returning: response)
-                        case .failure(let error):
-                            continuation.resume(throwing: error)
-                        }
+                        continuation.resume(with: result)
                     }
                     await cancellationHandler.register(with: sessionTask)
                 }

Sources/APIKit/Error/SessionTaskError.swift

@@ -10,4 +10,7 @@ public enum SessionTaskError: Error {
 
     /// Error while creating `Request.Response` from `(Data, URLResponse)`.
     case responseError(Error)
+
+    /// Error when the `Task` in Concurrency was cancelled before execution.
+    case taskAlreadyCancelledError
 }

Tests/APIKitTests/Concurrency/ConcurrencyTests.swift

@@ -0,0 +1,68 @@
+#if compiler(>=5.6.0) && canImport(_Concurrency)
+
+import XCTest
+import APIKit
+
+@available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+final class ConcurrencyTests: XCTestCase {
+    var adapter: TestSessionAdapter!
+    var session: Session!
+
+    override func setUp() {
+        super.setUp()
+        adapter = TestSessionAdapter()
+        session = Session(adapter: adapter)
+    }
+
+    func testSuccess() async throws {
+        let dictionary = ["key": "value"]
+        adapter.data = try XCTUnwrap(JSONSerialization.data(withJSONObject: dictionary, options: []))
+
+        let request = TestRequest()
+        let value = try await session.response(for: request)
+        XCTAssertEqual((value as? [String: String])?["key"], "value")
+    }
+
+    func testParseDataError() async throws {
+        adapter.data = "{\"broken\": \"json}".data(using: .utf8, allowLossyConversion: false)
+
+        let request = TestRequest()
+        do {
+            _ = try await session.response(for: request)
+            XCTFail()
+        } catch {
+            let sessionError = try XCTUnwrap(error as? SessionTaskError)
+            if case .responseError(let responseError as NSError) = sessionError {
+                XCTAssertEqual(responseError.domain, NSCocoaErrorDomain)
+                XCTAssertEqual(responseError.code, 3840)
+            } else {
+                XCTFail()
+            }
+        }
+    }
+
+    func testCancel() async throws {
+        let request = TestRequest()
+
+        let task = Task {
+            do {
+                _ = try await session.response(for: request)
+                XCTFail()
+            } catch  {
+                let sessionError = try XCTUnwrap(error as? SessionTaskError)
+                switch sessionError {
+                case .taskAlreadyCancelledError:
+                    XCTAssertTrue(Task.isCancelled)
+                default:
+                    XCTFail()
+                }
+            }
+        }
+        task.cancel()
+        _ = try await task.value
+
+        XCTAssertTrue(task.isCancelled)
+    }
+}
+
+#endif