Refactored task description usage and added some tests

AFNetworking/AFURLSessionManager.m

@@ -286,6 +286,7 @@ static inline BOOL af_addMethod(Class class, SEL selector, Method method) {
     return class_addMethod(class, selector,  method_getImplementation(method),  method_getTypeEncoding(method));
 }
 
+static void *AFNSURLSessionTaskSessionManagerKey = &AFNSURLSessionTaskSessionManagerKey;
 static NSString * const AFNSURLSessionTaskDidResumeNotification  = @"com.alamofire.networking.nsurlsessiontask.resume";
 static NSString * const AFNSURLSessionTaskDidSuspendNotification = @"com.alamofire.networking.nsurlsessiontask.suspend";
 
@@ -396,7 +397,6 @@ static NSString * const AFNSURLSessionTaskDidSuspendNotification = @"com.alamofi
 @property (readwrite, nonatomic, strong) NSOperationQueue *operationQueue;
 @property (readwrite, nonatomic, strong) NSURLSession *session;
 @property (readwrite, nonatomic, strong) NSMutableDictionary *mutableTaskDelegatesKeyedByTaskIdentifier;
-@property (readonly, nonatomic, copy) NSString *taskDescriptionForSessionTasks;
 @property (readwrite, nonatomic, strong) NSLock *lock;
 @property (readwrite, nonatomic, copy) AFURLSessionDidBecomeInvalidBlock sessionDidBecomeInvalid;
 @property (readwrite, nonatomic, copy) AFURLSessionDidReceiveAuthenticationChallengeBlock sessionDidReceiveAuthenticationChallenge;
@@ -477,29 +477,23 @@ static NSString * const AFNSURLSessionTaskDidSuspendNotification = @"com.alamofi
 
 #pragma mark -
 
-- (NSString *)taskDescriptionForSessionTasks {
-    return [NSString stringWithFormat:@"%p", self];
-}
-
 - (void)taskDidResume:(NSNotification *)notification {
     NSURLSessionTask *task = notification.object;
-    if ([task respondsToSelector:@selector(taskDescription)]) {
-        if ([task.taskDescription isEqualToString:self.taskDescriptionForSessionTasks]) {
-            dispatch_async(dispatch_get_main_queue(), ^{
-                [[NSNotificationCenter defaultCenter] postNotificationName:AFNetworkingTaskDidResumeNotification object:task];
-            });
-        }
+    AFURLSessionManager *manager = [self managerForTask:task];
+    if (self == manager) {
+        dispatch_async(dispatch_get_main_queue(), ^{
+            [[NSNotificationCenter defaultCenter] postNotificationName:AFNetworkingTaskDidResumeNotification object:task];
+        });
     }
 }
 
 - (void)taskDidSuspend:(NSNotification *)notification {
     NSURLSessionTask *task = notification.object;
-    if ([task respondsToSelector:@selector(taskDescription)]) {
-        if ([task.taskDescription isEqualToString:self.taskDescriptionForSessionTasks]) {
-            dispatch_async(dispatch_get_main_queue(), ^{
-                [[NSNotificationCenter defaultCenter] postNotificationName:AFNetworkingTaskDidSuspendNotification object:task];
-            });
-        }
+     AFURLSessionManager *manager = [self managerForTask:task];
+    if (self == manager) {
+        dispatch_async(dispatch_get_main_queue(), ^{
+            [[NSNotificationCenter defaultCenter] postNotificationName:AFNetworkingTaskDidSuspendNotification object:task];
+        });
     }
 }
 
@@ -534,7 +528,7 @@ static NSString * const AFNSURLSessionTaskDidSuspendNotification = @"com.alamofi
     delegate.manager = self;
     delegate.completionHandler = completionHandler;
 
-    dataTask.taskDescription = self.taskDescriptionForSessionTasks;
+    [self setManagerForTask:dataTask];
     [self setDelegate:delegate forTask:dataTask];
 }
 
@@ -571,8 +565,7 @@ static NSString * const AFNSURLSessionTaskDidSuspendNotification = @"com.alamofi
         *progress = delegate.progress;
     }
 
-    uploadTask.taskDescription = self.taskDescriptionForSessionTasks;
-
+    [self setManagerForTask:uploadTask];
     [self setDelegate:delegate forTask:uploadTask];
 }
 
@@ -595,8 +588,7 @@ static NSString * const AFNSURLSessionTaskDidSuspendNotification = @"com.alamofi
         *progress = delegate.progress;
     }
 
-    downloadTask.taskDescription = self.taskDescriptionForSessionTasks;
-
+    [self setManagerForTask:downloadTask];
     [self setDelegate:delegate forTask:downloadTask];
 }
 
@@ -854,6 +846,15 @@ static NSString * const AFNSURLSessionTaskDidSuspendNotification = @"com.alamofi
     self.downloadTaskDidResume = block;
 }
 
+#pragma mark - 
+- (void)setManagerForTask:(NSURLSessionTask *)task {
+    objc_setAssociatedObject(task, AFNSURLSessionTaskSessionManagerKey, self, OBJC_ASSOCIATION_ASSIGN);
+}
+
+- (nullable instancetype)managerForTask:(NSURLSessionTask *)task {
+    return objc_getAssociatedObject(task, AFNSURLSessionTaskSessionManagerKey);
+}
+
 #pragma mark - NSObject
 
 - (NSString *)description {

Tests/Tests/AFHTTPSessionManagerTests.m

@@ -161,6 +161,68 @@
     XCTAssertNotNil(downloadFilePath);
 }
 
+#pragma mark -
+
+- (void)testTaskDescriptionIsNilByDefault {
+    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"/get" relativeToURL:self.baseURL]];
+    XCTestExpectation *expectation = [self expectationWithDescription:@"Request should finish"];
+    NSURLSessionTask *testTask;
+    testTask = [self.manager
+                GET:request.URL.absoluteString
+                parameters:nil
+                success:^(NSURLSessionDataTask * _Nonnull task, id  _Nonnull responseObject) {
+                    XCTAssertNil(task.taskDescription,  @"taskDescription should be nil when request ends.");
+                    [expectation fulfill];
+                }
+                failure:nil];
+    XCTAssertNil(testTask.taskDescription, @"taskDescription should be nil when request starts.");
+    [self waitForExpectationsWithTimeout:5.0 handler:nil];
+}
+
+- (void)testThatTaskWithCustomTaskDescriptionPostsResumeNotification {
+    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"/get" relativeToURL:self.baseURL]];
+    XCTestExpectation *expectation = [self expectationWithDescription:@"Request should finish"];
+    NSString *taskDescription = @"this is a test!";
+    NSURLSessionTask *testTask;
+    testTask = [self.manager
+                dataTaskWithRequest:request
+                completionHandler:^(NSURLResponse * _Nonnull response, id  _Nullable responseObject, NSError * _Nullable error) {
+                    [expectation fulfill];
+                }];
+    testTask.taskDescription = taskDescription;
+    [testTask resume];
+    [self expectationForNotification:AFNetworkingTaskDidResumeNotification
+                              object:nil
+                             handler:^BOOL(NSNotification * _Nonnull notification) {
+                                 XCTAssertTrue([[(NSURLSessionTask *)notification.object taskDescription] isEqualToString:taskDescription]);
+                                 return YES;
+                             }];
+    [self waitForExpectationsWithTimeout:2.0 handler:nil];
+}
+
+
+- (void)testThatTaskWithCustomTaskDescriptionPostsSuspendNotification {
+    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"/get" relativeToURL:self.baseURL]];
+    XCTestExpectation *expectation = [self expectationWithDescription:@"Request should finish"];
+    NSString *taskDescription = @"this is a test!";
+    NSURLSessionTask *testTask;
+    testTask = [self.manager
+                dataTaskWithRequest:request
+                completionHandler:^(NSURLResponse * _Nonnull response, id  _Nullable responseObject, NSError * _Nullable error) {
+                    [expectation fulfill];
+                }];
+    testTask.taskDescription = taskDescription;
+    [testTask resume];
+    [testTask suspend];
+    [self expectationForNotification:AFNetworkingTaskDidSuspendNotification
+                              object:nil
+                             handler:^BOOL(NSNotification * _Nonnull notification) {
+                                 XCTAssertTrue([[(NSURLSessionTask *)notification.object taskDescription] isEqualToString:taskDescription]);
+                                 return YES;
+                             }];
+    [self waitForExpectationsWithTimeout:2.0 handler:nil];
+}
+
 
 
 @end