fix(ngMock): pass unexpected request failures in $httpBackend to the error handler

Closes #16150
Closes #15855

src/ng/q.js

@@ -364,6 +364,10 @@ function qFactory(nextTick, exceptionHandler, errorOnUnhandledRejections) {
           }
         } catch (e) {
           rejectPromise(promise, e);
+          // This error is explicitly marked for being passed to the $exceptionHandler
+          if (e && e.$$passToExceptionHandler === true) {
+            exceptionHandler(e);
+          }
         }
       }
     } finally {

src/ngMock/angular-mocks.js

@@ -1438,10 +1438,16 @@ function createHttpBackendMock($rootScope, $timeout, $delegate, $browser) {
         return;
       }
     }
-    throw wasExpected ?
+    var error = wasExpected ?
         new Error('No response defined !') :
         new Error('Unexpected request: ' + method + ' ' + url + '\n' +
                   (expectation ? 'Expected ' + expectation : 'No more request expected'));
+
+    // In addition to be being converted to a rejection, this error also needs to be passed to
+    // the $exceptionHandler and be rethrown (so that the test fails).
+    error.$$passToExceptionHandler = true;
+
+    throw error;
   }
 
   /**

test/ngMock/angular-mocksSpec.js

@@ -2429,7 +2429,7 @@ describe('ngMock', function() {
 
 describe('ngMockE2E', function() {
   describe('$httpBackend', function() {
-    var hb, realHttpBackend, realHttpBackendBrowser, callback;
+    var hb, realHttpBackend, realHttpBackendBrowser, $http, callback;
 
     beforeEach(function() {
       callback = jasmine.createSpy('callback');
@@ -2442,10 +2442,29 @@ describe('ngMockE2E', function() {
       module('ngMockE2E');
       inject(function($injector) {
         hb = $injector.get('$httpBackend');
+        $http = $injector.get('$http');
       });
     });
 
 
+    it('should throw error when unexpected request - without error callback', function() {
+      expect(function() {
+        $http.get('/some').then(noop);
+
+        hb.verifyNoOutstandingRequest();
+      }).toThrowError('Unexpected request: GET /some\nNo more request expected');
+    });
+
+
+    it('should throw error when unexpected request - with error callback', function() {
+      expect(function() {
+        $http.get('/some').then(noop, noop);
+
+        hb.verifyNoOutstandingRequest();
+      }).toThrowError('Unexpected request: GET /some\nNo more request expected');
+    });
+
+
     describe('passThrough()', function() {
       it('should delegate requests to the real backend when passThrough is invoked', function() {
         var eventHandlers = {progress: angular.noop};