Make InteractionManager tasks cancellable

Summary:
Returns a promise-like object with a new cancel function that will dig through the queue
and remove relevant tasks before they are executed. Handy when tasks are scheduled in react
components but should be cleaned up in unmount.

Reviewed By: devknoll

Differential Revision: D3406953

fbshipit-source-id: edf1157d831d5d6b63f13ee64cfd1c46843e79fa

Libraries/Interaction/__tests__/TaskQueue-test.js

@@ -1,5 +1,11 @@
 /**
- * Copyright 2004-present Facebook. All Rights Reserved.
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
  */
 
 'use strict';
@@ -15,7 +21,7 @@ function clearTaskQueue(taskQueue) {
     jest.runAllTimers();
     taskQueue.processNext();
     jest.runAllTimers();
-  } while (taskQueue.hasTasksToProcess())
+  } while (taskQueue.hasTasksToProcess());
 }
 
 describe('TaskQueue', () => {
@@ -118,4 +124,22 @@ describe('TaskQueue', () => {
     expectToBeCalledOnce(task3);
     expectToBeCalledOnce(task4);
   });
+
+  it('should be able to cancel tasks', () => {
+    const task1 = jest.fn();
+    const task2 = createSequenceTask(1);
+    const task3 = jest.fn();
+    const task4 = createSequenceTask(2);
+    taskQueue.enqueue(task1);
+    taskQueue.enqueue(task2);
+    taskQueue.enqueue(task3);
+    taskQueue.enqueue(task4);
+    taskQueue.cancelTasks([task1, task3]);
+    clearTaskQueue(taskQueue);
+    expect(task1).not.toBeCalled();
+    expect(task3).not.toBeCalled();
+    expectToBeCalledOnce(task2);
+    expectToBeCalledOnce(task4);
+    expect(taskQueue.hasTasksToProcess()).toBe(false);
+  });
 });