Merge pull request #109 from dbsystel/async-await

Cancel support in Async/Await

Author: lightsprint09

Source/NetworkService+Async.swift

@@ -28,10 +28,17 @@ public extension NetworkService {
      */
     @discardableResult
     func request<Result>(_ resource: Resource<Result>) async throws -> (Result, HTTPURLResponse) {
-        return try await withCheckedThrowingContinuation({ coninuation in
-            request(resource: resource, onCompletionWithResponse: {
-                coninuation.resume(with: $0)
+        var task: NetworkTask?
+        let cancel = { task?.cancel() }
+        return try await withTaskCancellationHandler(operation: {
+            try Task.checkCancellation()
+            return try await withCheckedThrowingContinuation({ coninuation in
+                task = request(resource: resource, onCompletionWithResponse: {
+                    coninuation.resume(with: $0)
+                })
             })
+        }, onCancel: {
+            cancel()
         })
     }
 
@@ -53,10 +60,17 @@ public extension NetworkService {
      */
     @discardableResult
     func request<Result, E: Error>(_ resource: ResourceWithError<Result, E>) async throws -> (Result, HTTPURLResponse) {
-        return try await withCheckedThrowingContinuation({ coninuation in
-            request(resource: resource, onCompletionWithResponse: {
-                coninuation.resume(with: $0)
+        var task: NetworkTask?
+        let cancel = { task?.cancel() }
+        return try await withTaskCancellationHandler(operation: {
+            try Task.checkCancellation()
+            return try await withCheckedThrowingContinuation({ coninuation in
+                task = request(resource: resource, onCompletionWithResponse: {
+                    coninuation.resume(with: $0)
+                })
             })
+        }, onCancel: {
+            cancel()
         })
     }
 

Tests/NetworkServiceTest.swift

@@ -268,4 +268,23 @@ class NetworkServiceTest: XCTestCase {
             XCTAssertTrue(error is NetworkError)
         }
     }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    func testGIVEN_aRequest_WHEN_requestWithAsyncResultAndResponseAndCancel_THEN_ShouldThwo() async {
+        // GIVEN
+        let error = NSError(domain: "", code: 0, userInfo: nil)
+        networkAccess.changeMock(data: nil, response: nil, error: error)
+
+        //When
+        let task = Task {
+            try await networkService.request(resource)
+        }
+        task.cancel()
+        let result = await task.result
+        if case .failure(let error) = result, let networkError = error as? CancellationError {
+           
+        } else {
+            XCTFail("Schould throw")
+        }
+    }
 }