Merge pull request #9885 from edx/andya/teams-router-testing

Improve team testing of routers

common/static/common/js/spec_helpers/page_helpers.js

@@ -1,18 +1,49 @@
-define([ // jshint ignore:line
-],
-function() {
-    'use strict';
-    var getLocationHash;
-    /**
-     * Helper method that returns url hash.
-     * @return {String} Returns anchor part of current url.
-     */
-    getLocationHash = function() {
-        return window.location.hash;
-    };
+define(["backbone"],
+    function(Backbone) {
+        'use strict';
+        var getLocationHash, preventBackboneChangingUrl;
 
-    return {
-        'getLocationHash': getLocationHash
-    };
+        /**
+         * Helper method that returns url hash.
+         * @return {String} Returns anchor part of current url.
+         */
+        getLocationHash = function() {
+            return window.location.hash;
+        };
 
-});
+        /**
+         * Prevent Backbone tests from changing the browser's URL.
+         *
+         * This function modifies Backbone so that tests can navigate
+         * without modifying the browser's URL. It works be adding
+         * stub versions of Backbone's hash functions so that updating
+         * the hash doesn't change the URL but instead updates a
+         * local object. The router's callbacks are still invoked
+         * so that to the test it appears that navigation is behaving
+         * as expected.
+         *
+         * Note: it is important that tests don't update the browser's
+         * URL because subsequent tests could find themselves in an
+         * unexpected navigation state.
+         */
+        preventBackboneChangingUrl = function() {
+            var history = {
+                currentFragment: ''
+            };
+
+            // Stub out the Backbone router so that the browser doesn't actually navigate
+            spyOn(Backbone.history, '_updateHash').andCallFake(function (location, fragment, replace) {
+                history.currentFragment = fragment;
+            });
+
+            // Stub out getHash so that Backbone thinks that the browser has navigated
+            spyOn(Backbone.history, 'getHash').andCallFake(function () {
+                return history.currentFragment;
+            });
+        };
+
+        return {
+            'getLocationHash': getLocationHash,
+            'preventBackboneChangingUrl': preventBackboneChangingUrl
+        };
+    });