Merge pull request #96 from futuredapp/feature/async-cancellation

Add cancellation support to async methods

Author: mkj-is

Sources/FTAPIKit/URLServer+Async.swift

@@ -1,4 +1,7 @@
 import Foundation
+#if os(Linux)
+import FoundationNetworking
+#endif
 
 // This extension is duplicated to support Xcode 13.0 and Xcode 13.1,
 // where backported concurrency is not available.
@@ -15,15 +18,20 @@ public extension URLServer {
     /// - Throws: Throws in case that result is .failure
     /// - Returns: Void on success
     func call(endpoint: Endpoint) async throws {
-        return try await withCheckedThrowingContinuation { continuation in
-            call(endpoint: endpoint) { result in
-                switch result {
-                case .success:
-                    continuation.resume()
-                case .failure(let error):
-                    continuation.resume(throwing: error)
+        var task: URLSessionTask?
+        return try await withTaskCancellationHandler {
+            try await withCheckedThrowingContinuation { continuation in
+                task = call(endpoint: endpoint) { result in
+                    switch result {
+                    case .success:
+                        continuation.resume()
+                    case .failure(let error):
+                        continuation.resume(throwing: error)
+                    }
                 }
             }
+        } onCancel: { [task] in
+            task?.cancel()
         }
     }
 
@@ -35,15 +43,20 @@ public extension URLServer {
     /// - Throws: Throws in case that result is .failure
     /// - Returns: Plain data returned with the HTTP Response
     func call(data endpoint: Endpoint) async throws -> Data {
-        return try await withCheckedThrowingContinuation { continuation in
-            call(data: endpoint) { result in
-                switch result {
-                case .success(let data):
-                    continuation.resume(returning: data)
-                case .failure(let error):
-                    continuation.resume(throwing: error)
+        var task: URLSessionTask?
+        return try await withTaskCancellationHandler {
+            try await withCheckedThrowingContinuation { continuation in
+                task = call(data: endpoint) { result in
+                    switch result {
+                    case .success(let data):
+                        continuation.resume(returning: data)
+                    case .failure(let error):
+                        continuation.resume(throwing: error)
+                    }
                 }
             }
+        } onCancel: { [task] in
+            task?.cancel()
         }
     }
 
@@ -55,15 +68,20 @@ public extension URLServer {
     /// - Throws: Throws in case that result is .failure
     /// - Returns: Instance of the required type
     func call<EP: ResponseEndpoint>(response endpoint: EP) async throws -> EP.Response {
-        return try await withCheckedThrowingContinuation { continuation in
-            call(response: endpoint) { result in
-                switch result {
-                case .success(let response):
-                    continuation.resume(returning: response)
-                case .failure(let error):
-                    continuation.resume(throwing: error)
+        var task: URLSessionTask?
+        return try await withTaskCancellationHandler {
+            try await withCheckedThrowingContinuation { continuation in
+                task = call(response: endpoint) { result in
+                    switch result {
+                    case .success(let response):
+                        continuation.resume(returning: response)
+                    case .failure(let error):
+                        continuation.resume(throwing: error)
+                    }
                 }
             }
+        } onCancel: { [task] in
+            task?.cancel()
         }
     }
 }
@@ -80,15 +98,20 @@ public extension URLServer {
     /// - Throws: Throws in case that result is .failure
     /// - Returns: Void on success
     func call(endpoint: Endpoint) async throws {
-        return try await withCheckedThrowingContinuation { continuation in
-            call(endpoint: endpoint) { result in
-                switch result {
-                case .success:
-                    continuation.resume()
-                case .failure(let error):
-                    continuation.resume(throwing: error)
+        var task: URLSessionTask?
+        return try await withTaskCancellationHandler {
+            try await withCheckedThrowingContinuation { continuation in
+                task = call(endpoint: endpoint) { result in
+                    switch result {
+                    case .success:
+                        continuation.resume()
+                    case .failure(let error):
+                        continuation.resume(throwing: error)
+                    }
                 }
             }
+        } onCancel: { [task] in
+            task?.cancel()
         }
     }
 
@@ -100,15 +123,20 @@ public extension URLServer {
     /// - Throws: Throws in case that result is .failure
     /// - Returns: Plain data returned with the HTTP Response
     func call(data endpoint: Endpoint) async throws -> Data {
-        return try await withCheckedThrowingContinuation { continuation in
-            call(data: endpoint) { result in
-                switch result {
-                case .success(let data):
-                    continuation.resume(returning: data)
-                case .failure(let error):
-                    continuation.resume(throwing: error)
+        var task: URLSessionTask?
+        return try await withTaskCancellationHandler {
+            try await withCheckedThrowingContinuation { continuation in
+                task = call(data: endpoint) { result in
+                    switch result {
+                    case .success(let data):
+                        continuation.resume(returning: data)
+                    case .failure(let error):
+                        continuation.resume(throwing: error)
+                    }
                 }
             }
+        } onCancel: { [task] in
+            task?.cancel()
         }
     }
 
@@ -120,15 +148,20 @@ public extension URLServer {
     /// - Throws: Throws in case that result is .failure
     /// - Returns: Instance of the required type
     func call<EP: ResponseEndpoint>(response endpoint: EP) async throws -> EP.Response {
-        return try await withCheckedThrowingContinuation { continuation in
-            call(response: endpoint) { result in
-                switch result {
-                case .success(let response):
-                    continuation.resume(returning: response)
-                case .failure(let error):
-                    continuation.resume(throwing: error)
+        var task: URLSessionTask?
+        return try await withTaskCancellationHandler {
+            try await withCheckedThrowingContinuation { continuation in
+                task = call(response: endpoint) { result in
+                    switch result {
+                    case .success(let response):
+                        continuation.resume(returning: response)
+                    case .failure(let error):
+                        continuation.resume(throwing: error)
+                    }
                 }
             }
+        } onCancel: { [task] in
+            task?.cancel()
         }
     }
 }