[js] Change Deferred#cancel() to silently no-op if the deferred has a…

…lready been resolved.

Fixes issue 6686

javascript/node/selenium-webdriver/CHANGES.md

@@ -1,3 +1,8 @@
+## v2.38.1
+
+* FIXED: 6686: Changed `webdriver.promise.Deferred#cancel()` to silently no-op
+    if the deferred has already been resolved.
+
 ## v2.38.0
 
 * When a promise is rejected, always annotate the stacktrace with the parent

javascript/node/selenium-webdriver/package.json

@@ -1,6 +1,6 @@
 {
     "name": "selenium-webdriver",
-    "version": "2.38.0",
+    "version": "2.38.1",
     "description": "The official WebDriver JavaScript bindings from the Selenium project",
     "keywords": [
         "automation",

javascript/webdriver/promise.js

@@ -273,7 +273,7 @@ webdriver.promise.Deferred = function(opt_canceller, opt_flow) {
    */
   function removeAll() {
     if (!isPending()) {
-      throw new Error('This Deferred has already been resolved.');
+      throw new Error('This Deferred has already been resolved. (1)');
     }
     listeners = [];
   }
@@ -288,7 +288,7 @@ webdriver.promise.Deferred = function(opt_canceller, opt_flow) {
    */
   function notifyAll(newState, newValue) {
     if (!isPending()) {
-      throw new Error('This Deferred has already been resolved.');
+      throw new Error('This Deferred has already been resolved. (2)');
     }
 
     state = newState;
@@ -431,13 +431,13 @@ webdriver.promise.Deferred = function(opt_canceller, opt_flow) {
   }
 
   /**
-   * Cancels the computation of this promise's value and flags the promise as a
-   * rejected value.
+   * Attempts to cancel the computation of this instance's value. This attempt
+   * will silently fail if this instance has already resolved.
    * @param {*=} opt_reason The reason for cancelling this promise.
    */
   function cancel(opt_reason) {
     if (!isPending()) {
-      throw Error('This Deferred has already been resolved.');
+      return;
     }
 
     if (opt_canceller) {

javascript/webdriver/test/promise_test.html

@@ -37,15 +37,15 @@
     throwStubError = webdriver.test.testutil.throwStubError,
     STUB_ERROR = webdriver.test.testutil.STUB_ERROR;
 
-var app, clock, uncaughtException;
+var app, clock, uncaughtExceptions;
 
 function setUp() {
   clock = webdriver.test.testutil.createMockClock();
-  uncaughtException = callbackHelper();
+  uncaughtExceptions = [];
 
   app = webdriver.promise.controlFlow();
   app.on(webdriver.promise.ControlFlow.EventType.UNCAUGHT_EXCEPTION,
-         uncaughtException);
+         goog.bind(uncaughtExceptions.push, uncaughtExceptions));
 
   // The application timer defaults to a protected copies of the native
   // timing functions. Reset it to use |window|, which has been modified
@@ -58,7 +58,8 @@
   webdriver.test.testutil.consumeTimeouts();
   clock.dispose();
   app.reset();
-  uncaughtException.assertNotCalled();
+  assertArrayEquals(
+      'Did not expect any uncaught exceptions', [], uncaughtExceptions);
 }
 
 
@@ -1132,9 +1133,32 @@
 }
 
 
-function testCancel_cannotCancelADeferredThatHasBeenResolved() {
-  var d = webdriver.promise.fulfilled(123);
-  assertThrows(d.cancel);
+function testCancel_cancelIsANoopOnceAPromiseHasBeenFulfilled() {
+  var p = webdriver.promise.fulfilled(123);
+  p.cancel();
+
+  var pair = callbackPair(goog.partial(assertEquals, 123));
+  p.then(pair.callback, pair.errback);
+  pair.assertCallback();
+}
+
+
+function testCancel_cancelIsANoopOnceAPromiseHasBeenRejected() {
+  var p = webdriver.promise.rejected(STUB_ERROR);
+  p.cancel();
+
+  var pair = callbackPair(null, assertIsStubError);
+  p.then(pair.callback, pair.errback);
+  pair.assertErrback();
+}
+
+
+function testCancel_noopCancelTriggeredOnCallbackOfResolvedPromise() {
+  var d = webdriver.promise.defer();
+  var p = d.then();
+
+  d.fulfill();
+  p.cancel();  // This should not throw.
 }
 
 

javascript/webdriver/test/webdriver_test.html

@@ -86,8 +86,8 @@
 
   function expectedError(code, message) {
     return function(e) {
-      assertEquals('Wrong error code', code, e.code);
       assertEquals('Wrong error message', message, e.message);
+      assertEquals('Wrong error code', code, e.code);
     };
   }
 
@@ -1532,6 +1532,24 @@
   }
 
 
+  function testFindElement_elementNotFoundInACallback() {
+    var testHelper = TestHelper.
+        expectingFailure(
+            expectedError(ECode.NO_SUCH_ELEMENT, 'Unable to find element')).
+        expect(CName.FIND_ELEMENT, {'using':'id', 'value':'foo'}).
+        andReturnError(
+            ECode.NO_SUCH_ELEMENT, {'message':'Unable to find element'}).
+        replayAll();
+
+    var driver = testHelper.createDriver();
+    webdriver.promise.fulfilled().then(function() {
+      var element = driver.findElement(By.id('foo'));
+      return element.click();  // Should not execute.
+    });
+    testHelper.execute();
+  }
+
+
   function testFindElement_elementFound() {
     var testHelper = TestHelper.expectingSuccess().
         expect(CName.FIND_ELEMENT, {'using':'id', 'value':'foo'}).