feat($q): report promises with non rejection callback

Rejected promises that do not have a callback to handle the rejection report
this to $exceptionHandler so they can be logged to the console.

BREAKING CHANGE

Tests that depend on specific order or number of messages in $exceptionHandler
will need to handle rejected promises report.

Closes: angular#13653
Closes: angular#7992

Author: lgalfaso

src/ng/compile.js

@@ -2716,7 +2716,7 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
               childBoundTranscludeFn);
           }
           linkQueue = null;
-        });
+        }).then(noop, noop);
 
       return function delayedNodeLinkFn(ignoreChildLinkFn, scope, node, rootElement, boundTranscludeFn) {
         var childBoundTranscludeFn = boundTranscludeFn;

src/ng/interval.js

@@ -188,6 +188,8 @@ function $IntervalProvider() {
       */
     interval.cancel = function(promise) {
       if (promise && promise.$$intervalId in intervals) {
+        // Interval cancels should not report as unhandled promise.
+        intervals[promise.$$intervalId].promise.then(noop, noop);
         intervals[promise.$$intervalId].reject('canceled');
         $window.clearInterval(promise.$$intervalId);
         delete intervals[promise.$$intervalId];

src/ng/q.js

@@ -217,20 +217,51 @@
  * @returns {Promise} The newly created promise.
  */
 function $QProvider() {
-
+  var errorOnUnhandledRejections = true;
   this.$get = ['$rootScope', '$exceptionHandler', function($rootScope, $exceptionHandler) {
     return qFactory(function(callback) {
       $rootScope.$evalAsync(callback);
-    }, $exceptionHandler);
+    }, $exceptionHandler, errorOnUnhandledRejections);
   }];
+
+  /**
+   * @ngdoc method
+   * @name $qProvider#errorOnUnhandledRejections
+   * @kind function
+   *
+   * @description
+   * Retrieves or overrides on wheter to generate an error when a rejected promise is not handled.
+   *
+   * @param {boolean=} value Wheter to generate an error when a rejected promise is not handled.
+   * @returns {boolean|ng.$qProvider} Current value when called without a new value or self for
+   *    chaining otherwise.
+   */
+  this.errorOnUnhandledRejections = function(value) {
+    if (isDefined(value)) {
+      errorOnUnhandledRejections = value;
+      return this;
+    } else {
+      return errorOnUnhandledRejections;
+    }
+  };
 }
 
 function $$QProvider() {
+  var errorOnUnhandledRejections = true;
   this.$get = ['$browser', '$exceptionHandler', function($browser, $exceptionHandler) {
     return qFactory(function(callback) {
       $browser.defer(callback);
-    }, $exceptionHandler);
+    }, $exceptionHandler, errorOnUnhandledRejections);
   }];
+
+  this.errorOnUnhandledRejections = function(value) {
+    if (isDefined(value)) {
+      errorOnUnhandledRejections = value;
+      return this;
+    } else {
+      return errorOnUnhandledRejections;
+    }
+  };
 }
 
 /**
@@ -239,10 +270,14 @@ function $$QProvider() {
  * @param {function(function)} nextTick Function for executing functions in the next turn.
  * @param {function(...*)} exceptionHandler Function into which unexpected exceptions are passed for
  *     debugging purposes.
+ @ param {=boolean} errorOnUnhandledRejections Whether an error should be generated on unhandled
+ *     promises rejections.
  * @returns {object} Promise manager.
  */
-function qFactory(nextTick, exceptionHandler) {
+function qFactory(nextTick, exceptionHandler, errorOnUnhandledRejections) {
   var $qMinErr = minErr('$q', TypeError);
+  var queueSize = 0;
+  var checkQueue = [];
 
   /**
    * @ngdoc method
@@ -307,28 +342,62 @@ function qFactory(nextTick, exceptionHandler) {
     pending = state.pending;
     state.processScheduled = false;
     state.pending = undefined;
-    for (var i = 0, ii = pending.length; i < ii; ++i) {
-      deferred = pending[i][0];
-      fn = pending[i][state.status];
-      try {
-        if (isFunction(fn)) {
-          deferred.resolve(fn(state.value));
-        } else if (state.status === 1) {
-          deferred.resolve(state.value);
-        } else {
-          deferred.reject(state.value);
+    try {
+      for (var i = 0, ii = pending.length; i < ii; ++i) {
+        state.pur = true;
+        deferred = pending[i][0];
+        fn = pending[i][state.status];
+        try {
+          if (isFunction(fn)) {
+            deferred.resolve(fn(state.value));
+          } else if (state.status === 1) {
+            deferred.resolve(state.value);
+          } else {
+            deferred.reject(state.value);
+          }
+        } catch (e) {
+          deferred.reject(e);
+          exceptionHandler(e);
         }
-      } catch (e) {
-        deferred.reject(e);
-        exceptionHandler(e);
+      }
+    } finally {
+      --queueSize;
+      if (queueSize === 0) {
+        nextTick(processChecksFn());
+      }
+    }
+  }
+
+  function processChecks() {
+    while (!queueSize && checkQueue.length) {
+      var toCheck = checkQueue.shift();
+      if (errorOnUnhandledRejections && !toCheck.pur) {
+        toCheck.pur = true;
+        var errorMessage = 'Possibly unhandled rejection: ' + toDebugString(toCheck.value);
+        exceptionHandler(errorMessage);
       }
     }
   }
 
+  function processChecksFn() {
+    return function() { processChecks(); };
+  }
+
+  function processQueueFn(state) {
+    return function() { processQueue(state); };
+  }
+
   function scheduleProcessQueue(state) {
+    if (!state.pending && state.status === 2 && !state.pur) {
+      if (queueSize === 0 && checkQueue.length === 0) {
+        nextTick(processChecksFn());
+      }
+      checkQueue.push(state);
+    }
     if (state.processScheduled || !state.pending) return;
     state.processScheduled = true;
-    nextTick(function() { processQueue(state); });
+    ++queueSize;
+    nextTick(processQueueFn(state));
   }
 
   function Deferred() {

src/ng/timeout.js

@@ -85,6 +85,8 @@ function $TimeoutProvider() {
       */
     timeout.cancel = function(promise) {
       if (promise && promise.$$timeoutId in deferreds) {
+        // Timeout cancels should not report an unhandled promise.
+        deferreds[promise.$$timeoutId].promise.then(noop, noop);
         deferreds[promise.$$timeoutId].reject('canceled');
         delete deferreds[promise.$$timeoutId];
         return $browser.defer.cancel(promise.$$timeoutId);

src/ngMock/angular-mocks.js

@@ -445,7 +445,7 @@ angular.mock.$IntervalProvider = function() {
           promise = deferred.promise;
 
       count = (angular.isDefined(count)) ? count : 0;
-      promise.then(null, null, (!hasParams) ? fn : function() {
+      promise.then(null, function() {}, (!hasParams) ? fn : function() {
         fn.apply(null, args);
       });
 
@@ -505,6 +505,7 @@ angular.mock.$IntervalProvider = function() {
       });
 
       if (angular.isDefined(fnIndex)) {
+        repeatFns[fnIndex].deferred.promise.then(undefined, function() {});
         repeatFns[fnIndex].deferred.reject('canceled');
         repeatFns.splice(fnIndex, 1);
         return true;

src/ngResource/resource.js

@@ -706,13 +706,14 @@ angular.module('ngResource', ['ng']).
               return $q.reject(response);
             });
 
-            promise['finally'](function() {
+            promise = promise['finally'](function(response) {
               value.$resolved = true;
               if (!isInstanceCall && cancellable) {
                 value.$cancelRequest = angular.noop;
                 $timeout.cancel(numericTimeoutPromise);
                 timeoutDeferred = numericTimeoutPromise = httpConfig.timeout = null;
               }
+              return response;
             });
 
             promise = promise.then(

test/ng/animateRunnerSpec.js

@@ -206,7 +206,7 @@ describe("$$AnimateRunner", function() {
         var animationComplete = false;
         runner.finally(function() {
           animationComplete = true;
-        });
+        }).then(noop, noop);
         runner[method]();
         $rootScope.$digest();
         expect(animationComplete).toBe(true);

test/ng/httpSpec.js

@@ -1031,7 +1031,7 @@ describe('$http', function() {
 
       it('should $apply after error callback', function() {
         $httpBackend.when('GET').respond(404);
-        $http({method: 'GET', url: '/some'});
+        $http({method: 'GET', url: '/some'}).then(noop, noop);
         $httpBackend.flush();
         expect($rootScope.$apply).toHaveBeenCalledOnce();
       });
@@ -1432,7 +1432,7 @@ describe('$http', function() {
 
       function doFirstCacheRequest(method, respStatus, headers) {
         $httpBackend.expect(method || 'GET', '/url').respond(respStatus || 200, 'content', headers);
-        $http({method: method || 'GET', url: '/url', cache: cache});
+        $http({method: method || 'GET', url: '/url', cache: cache}).then(noop, noop);
         $httpBackend.flush();
       }
 
@@ -1640,7 +1640,7 @@ describe('$http', function() {
 
       it('should preserve config object when rejecting from pending cache', function() {
         $httpBackend.expect('GET', '/url').respond(404, 'content');
-        $http({method: 'GET', url: '/url', cache: cache, headers: {foo: 'bar'}});
+        $http({method: 'GET', url: '/url', cache: cache, headers: {foo: 'bar'}}).then(noop, noop);
 
         $http({method: 'GET', url: '/url', cache: cache, headers: {foo: 'baz'}}).catch(callback);
         $httpBackend.flush();