Add another parameter to the HTTPManager.MetricsCallback callback

In order to retain backwards compatibility, the existing initializer and
property were deprecated and a new initializer and property with
different names were added.

Fixes #41.

Author: lilyball

README.md

@@ -413,6 +413,7 @@ work by you shall be dual licensed as above, without any additional terms or con
 #### Development
 
 * Expose `HTTPManagerTask.userInitiated` as a public property.
+* Add another parameter to the `HTTPManager.MetricsCallback` callback. In order to retain backwards compatibility, the old initializer and property were deprecated and a new initializer and property were added with different names.
 
 #### v4.2.0 (2018-07-10)
 

Sources/HTTPManager.swift

@@ -1611,20 +1611,49 @@ public final class HTTPManagerMetricsCallback: NSObject {
 
     /// The callback that will be invoked with task metrics.
     /// - Parameter task: The task for which metrics were collected.
+    /// - Parameter urlTask: The underlying network task for which metrics were collected.
+    ///             This may be different than `task.networkTask` if the task is configured with
+    ///             automatic retry behavior.
     /// - Parameter metrics: The task metrics that were collected.
-    @objc public let callback: (_ task: HTTPManagerTask, _ metrics: URLSessionTaskMetrics) -> Void
+    @objc public let handler: (_ task: HTTPManagerTask, _ urlTask: URLSessionTask, _ metrics: URLSessionTaskMetrics) -> Void
+    
+    /// The callback that will be invoked with task metrics.
+    /// - Parameter task: The task for which metrics were collected.
+    /// - Parameter metrics: The task metrics that were collected.
+    @available(*, deprecated, message: "Use .handler instead")
+    @objc public var callback: (_ task: HTTPManagerTask, _ metrics: URLSessionTaskMetrics) -> Void {
+        return _callback ?? { [handler] (task, metrics) in
+            handler(task, task.networkTask, metrics)
+        }
+    }
+    private var _callback: ((_ task: HTTPManagerTask, _ metrics: URLSessionTaskMetrics) -> Void)?
 
     /// Returns a new `HTTPManagerMetricsCallback` object.
     /// - Parameter queue: The operation queue that the callback will be invoked on. If `nil`, the
     ///   callback will be invoked on a global background queue with the `.utility` QoS.
-    /// - Parameter callback: The callback that will be invoked with task metrics.
+    /// - Parameter handler: The callback that will be invoked with task metrics.
     /// - Parameter task: The task for which metrics were collected.
+    /// - Parameter urlTask: The underlying network task for which metrics were collected.
+    ///             This may be different than `task.networkTask` if the task is configured with
+    ///             automatic retry behavior.
     /// - Parameter metrics: The task metrics that were collected.
-    @objc public init(queue: OperationQueue?, callback: @escaping (_ task: HTTPManagerTask, _ metrics: URLSessionTaskMetrics) -> Void) {
+    @objc public init(queue: OperationQueue?, handler: @escaping (_ task: HTTPManagerTask, _ urlTask: URLSessionTask, _ metrics: URLSessionTaskMetrics) -> Void) {
         self.queue = queue
-        self.callback = callback
+        self.handler = handler
         super.init()
     }
+    
+    /// Returns a new `HTTPManagerMetricsCallback` object.
+    /// - Parameter queue: The operation queue that the callback will be invoked on. If `nil`, the
+    ///   callback will be invoked on a global background queue with the `.utility` QoS.
+    /// - Parameter callback: The callback that will be invoked with task metrics.
+    /// - Parameter task: The task for which metrics were collected.
+    /// - Parameter metrics: The task metrics that were collected.
+    @available(*, deprecated, message: "Use init(queue:handler:) instead")
+    @objc public convenience init(queue: OperationQueue?, callback: @escaping (_ task: HTTPManagerTask, _ metrics: URLSessionTaskMetrics) -> Void) {
+        self.init(queue: queue, handler: { (task, urlTask, metrics) in callback(task, metrics) })
+        _callback = callback
+    }
 }
 
 // MARK: - Private
@@ -2267,12 +2296,12 @@ extension MetricsSessionDelegate {
         assert(apiTask.networkTask === task, "internal HTTPManager error: taskInfo out of sync")
         log("task:didFinishCollecting for task \(task)")
         if let operationQueue = metricsCallback.queue {
-            operationQueue.addOperation { [callback=metricsCallback.callback] in
-                callback(apiTask, metrics)
+            operationQueue.addOperation { [callback=metricsCallback.handler] in
+                callback(apiTask, task, metrics)
             }
         } else {
-            DispatchQueue.global(qos: .utility).async { [callback=metricsCallback.callback] in
-                callback(apiTask, metrics)
+            DispatchQueue.global(qos: .utility).async { [callback=metricsCallback.handler] in
+                callback(apiTask, task, metrics)
             }
         }
     }

Tests/MetricsCallbackTests.swift

@@ -30,7 +30,7 @@ final class MetricsCallbackTests: PMHTTPTestCase {
             }
             var task: HTTPManagerTask?
             let expectation = self.expectation(description: "task metrics")
-            HTTP.metricsCallback = .init(queue: nil, callback: { (task_, metrics) in
+            HTTP.metricsCallback = .init(queue: nil, handler: { (task_, networkTask, metrics) in
                 XCTAssert(task === task_, "unexpected task")
                 expectation.fulfill()
             })
@@ -48,7 +48,7 @@ final class MetricsCallbackTests: PMHTTPTestCase {
             var task: HTTPManagerTask?
             let operationQueue = OperationQueue()
             let expectation = self.expectation(description: "task metrics")
-            HTTP.metricsCallback = .init(queue: operationQueue, callback: { (task_, metrics) in
+            HTTP.metricsCallback = .init(queue: operationQueue, handler: { (task_, networkTask, metrics) in
                 XCTAssertEqual(OperationQueue.current, operationQueue)
                 XCTAssert(task === task_, "unexpected task")
                 expectation.fulfill()
@@ -70,7 +70,7 @@ final class MetricsCallbackTests: PMHTTPTestCase {
             var requestFinished = false
             var task: HTTPManagerTask?
             let expectation = self.expectation(description: "task metrics")
-            HTTP.metricsCallback = .init(queue: operationQueue, callback: { (task_, metrics) in
+            HTTP.metricsCallback = .init(queue: operationQueue, handler: { (task_, networkTask, metrics) in
                 XCTAssertEqual(OperationQueue.current, operationQueue)
                 XCTAssert(task === task_, "unexpected task")
                 XCTAssertFalse(requestFinished, "recieved metrics after task finished")
@@ -107,7 +107,7 @@ final class MetricsCallbackTests: PMHTTPTestCase {
             let expectation = self.expectation(description: "task metrics")
             expectation.expectedFulfillmentCount = 3
             expectation.assertForOverFulfill = true
-            HTTP.metricsCallback = .init(queue: operationQueue, callback: { (task_, metrics) in
+            HTTP.metricsCallback = .init(queue: operationQueue, handler: { (task_, networkTask, metrics) in
                 XCTAssert(task === task_, "unexpected task")
                 expectation.fulfill()
             })
@@ -125,7 +125,7 @@ final class MetricsCallbackTests: PMHTTPTestCase {
                 completionHandler(HTTPServer.Response(status: .ok))
             }
             expectationForRequestSuccess(HTTP.request(GET: "foo"), startAutomatically: true)
-            HTTP.metricsCallback = .init(queue: nil, callback: { (_, _) in }) // this resets the session asynchronously
+            HTTP.metricsCallback = .init(queue: nil, handler: { (_, _, _) in }) // this resets the session asynchronously
             _ = HTTP.sessionConfiguration // this waits for the session reset to complete
             sema.signal()
             waitForExpectations(timeout: 1, handler: nil)
@@ -144,7 +144,7 @@ final class MetricsCallbackTests: PMHTTPTestCase {
             expectationForRequestSuccess(HTTP.request(GET: "foo"), queue: operationQueue, startAutomatically: true)
             let expectation = XCTestExpectation(description: "task metrics")
             expectation.isInverted = true
-            HTTP.metricsCallback = .init(queue: operationQueue, callback: { (_, _) in
+            HTTP.metricsCallback = .init(queue: operationQueue, handler: { (_, _, _) in
                 expectation.fulfill()
             })
             sema.signal()
@@ -160,12 +160,12 @@ final class MetricsCallbackTests: PMHTTPTestCase {
             }
             let expectationFirst = XCTestExpectation(description: "first task metrics")
             expectationFirst.isInverted = true
-            HTTP.metricsCallback = .init(queue: nil, callback: { (task_, metrics) in
+            HTTP.metricsCallback = .init(queue: nil, handler: { (task_, networkTask, metrics) in
                 expectationFirst.fulfill()
             })
             let task = expectationForRequestSuccess(HTTP.request(GET: "foo"), startAutomatically: false)
             let expectationSecond = self.expectation(description: "second task metrics")
-            HTTP.metricsCallback = .init(queue: nil, callback: { (task_, metrics) in
+            HTTP.metricsCallback = .init(queue: nil, handler: { (task_, networkTask, metrics) in
                 XCTAssert(task === task_, "unexpected task")
                 expectationSecond.fulfill()
             })
@@ -184,7 +184,7 @@ final class MetricsCallbackTests: PMHTTPTestCase {
             }
             let expectation = XCTestExpectation(description: "task metrics")
             expectation.isInverted = true
-            HTTP.metricsCallback = .init(queue: nil, callback: { (_, _) in
+            HTTP.metricsCallback = .init(queue: nil, handler: { (_, _, _) in
                 expectation.fulfill()
             })
             let operationQueue = OperationQueue()