Merge pull request #76 from JosephEarl/feature/whenall-result

Add taskForCompletionOfAllTasksWithResults and faulted property

Bolts/Common/BFTask.h

@@ -55,6 +55,14 @@ typedef id(^BFContinuationBlock)(BFTask *task);
  */
 + (instancetype)taskForCompletionOfAllTasks:(NSArray *)tasks;
 
+/*!
+ Returns a task that will be completed once all of the input tasks have completed. 
+ If all tasks complete successfully without being faulted or cancelled the result will be
+ an `NSArray` of all task results in the order they were provided.
+ @param tasks An `NSArray` of the tasks to use as an input.
+ */
++ (instancetype)taskForCompletionOfAllTasksWithResults:(NSArray *)tasks;
+
 /*!
  Returns a task that will be completed a certain amount of time in the future.
  @param millis The approximate number of milliseconds to wait before the
@@ -98,6 +106,11 @@ typedef id(^BFContinuationBlock)(BFTask *task);
  */
 @property (nonatomic, assign, readonly, getter = isCancelled) BOOL cancelled;
 
+/*!
+ Whether this task has completed due to an error or exception.
+ */
+@property (nonatomic, assign, readonly, getter = isFaulted) BOOL faulted;
+
 /*!
  Whether this task has completed.
  */

Bolts/Common/BFTask.m

@@ -26,6 +26,7 @@ @interface BFTask () {
 }
 
 @property (atomic, assign, readwrite, getter = isCancelled) BOOL cancelled;
+@property (atomic, assign, readwrite, getter = isFaulted) BOOL faulted;
 @property (atomic, assign, readwrite, getter = isCompleted) BOOL completed;
 
 @property (nonatomic, retain, readwrite) NSObject *lock;
@@ -131,6 +132,12 @@ + (instancetype)taskForCompletionOfAllTasks:(NSArray *)tasks {
     return tcs.task;
 }
 
++ (instancetype)taskForCompletionOfAllTasksWithResults:(NSArray *)tasks {
+    return [[self taskForCompletionOfAllTasks:tasks] continueWithSuccessBlock:^id(BFTask *task) {
+        return [tasks valueForKey:@"result"];
+    }];
+}
+
 + (instancetype)taskWithDelay:(int)millis {
     BFTaskCompletionSource *tcs = [BFTaskCompletionSource taskCompletionSource];
     dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, millis * NSEC_PER_MSEC);
@@ -191,6 +198,7 @@ - (BOOL)trySetError:(NSError *)error {
             return NO;
         }
         self.completed = YES;
+        self.faulted = YES;
         _error = error;
         [self runContinuations];
         return YES;
@@ -216,6 +224,7 @@ - (BOOL)trySetException:(NSException *)exception {
             return NO;
         }
         self.completed = YES;
+        self.faulted = YES;
         _exception = exception;
         [self runContinuations];
         return YES;
@@ -228,6 +237,12 @@ - (BOOL)isCancelled {
     }
 }
 
+- (BOOL)isFaulted {
+    @synchronized (self.lock) {
+        return _faulted;
+    }
+}
+
 - (void)cancel {
     @synchronized (self.lock) {
         if (![self trySetCancelled]) {

BoltsTests/TaskTests.m

@@ -433,6 +433,50 @@ - (void)testTaskForCompletionOfAllTasksCancelled {
     }] waitUntilFinished];
 }
 
+- (void)testTaskForCompletionOfAllTasksNoTasksImmediateCompletion {
+    NSMutableArray *tasks = [NSMutableArray array];
+
+    BFTask *task = [BFTask taskForCompletionOfAllTasks:tasks];
+    XCTAssertTrue(task.completed);
+    XCTAssertFalse(task.cancelled);
+    XCTAssertFalse(task.faulted);
+}
+
+- (void)testTaskForCompletionOfAllTasksWithResultsSuccess {
+    NSMutableArray *tasks = [NSMutableArray array];
+
+    const int kTaskCount = 20;
+    for (int i = 0; i < kTaskCount; ++i) {
+        double sleepTimeInMs = i * 10;
+        int result = i + 1;
+        [tasks addObject:[[BFTask taskWithDelay:sleepTimeInMs] continueWithBlock:^id(BFTask *task) {
+            return @(result);
+        }]];
+    }
+
+    [[[BFTask taskForCompletionOfAllTasksWithResults:tasks] continueWithBlock:^id(BFTask *task) {
+        XCTAssertFalse(task.cancelled);
+        XCTAssertFalse(task.faulted);
+
+        NSArray *results = task.result;
+        for (int i = 0; i < kTaskCount; ++i) {
+            NSNumber *individualResult = [results objectAtIndex:i];
+            XCTAssertEqual([individualResult intValue], [((BFTask *)[tasks objectAtIndex:i]).result intValue]);
+        }
+        return nil;
+    }] waitUntilFinished];
+}
+
+- (void)testTaskForCompletionOfAllTasksWithResultsNoTasksImmediateCompletion {
+    NSMutableArray *tasks = [NSMutableArray array];
+
+    BFTask *task = [BFTask taskForCompletionOfAllTasksWithResults:tasks];
+    XCTAssertTrue(task.completed);
+    XCTAssertFalse(task.cancelled);
+    XCTAssertFalse(task.faulted);
+    XCTAssertTrue(task.result != nil);
+}
+
 - (void)testWaitUntilFinished {
     BFTask *task = [[BFTask taskWithDelay:50] continueWithBlock:^id(BFTask *task) {
         return @"foo";