Improve team testing of routers

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

-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
+        };
+    });

lms/djangoapps/teams/static/teams/js/spec/teams_tab_factory_spec.js

 define(['jquery', 'backbone', 'teams/js/teams_tab_factory',
-        'teams/js/spec_helpers/team_spec_helpers'],
-    function($, Backbone, TeamsTabFactory, TeamSpecHelpers) {
+        'common/js/spec_helpers/page_helpers', 'teams/js/spec_helpers/team_spec_helpers'],
+    function($, Backbone, TeamsTabFactory, PageHelpers, TeamSpecHelpers) {
         'use strict';
 
         describe("Teams Tab Factory", function() {
@@ -10,6 +10,7 @@ define(['jquery', 'backbone', 'teams/js/teams_tab_factory',
 
             beforeEach(function() {
                 setFixtures('<section class="teams-content"></section>');
+                PageHelpers.preventBackboneChangingUrl();
             });
 
             afterEach(function() {
@@ -17,11 +18,6 @@ define(['jquery', 'backbone', 'teams/js/teams_tab_factory',
             });
 
             it('can render the "Teams" tab', function() {
-                // Hack to make sure the URL fragments from earlier
-                // tests don't interfere with Backbone routing by the
-                // teams tab view
-                document.location.hash = '';
-
                 initializeTeamsTabFactory();
                 expect($('.teams-content').text()).toContain('See all teams in your course, organized by topic');
             });

lms/djangoapps/teams/static/teams/js/spec/views/edit_team_spec.js

@@ -3,10 +3,11 @@ define([
     'underscore',
     'backbone',
     'common/js/spec_helpers/ajax_helpers',
+    'common/js/spec_helpers/page_helpers',
     'teams/js/views/edit_team',
     'teams/js/models/team',
     'teams/js/spec_helpers/team_spec_helpers'
-], function ($, _, Backbone, AjaxHelpers, TeamEditView, TeamModel, TeamSpecHelpers) {
+], function ($, _, Backbone, AjaxHelpers, PageHelpers, TeamEditView, TeamModel, TeamSpecHelpers) {
     'use strict';
 
     describe('CreateEditTeam', function() {
@@ -90,6 +91,7 @@ define([
 
         beforeEach(function () {
             setFixtures('<div class="teams-content"></div>');
+            PageHelpers.preventBackboneChangingUrl();
             spyOn(Backbone.history, 'navigate');
         });
 

lms/djangoapps/teams/static/teams/js/spec/views/instructor_tools_spec.js

@@ -6,8 +6,9 @@ define([
     'teams/js/views/instructor_tools',
     'teams/js/views/team_utils',
     'teams/js/spec_helpers/team_spec_helpers',
-    'common/js/spec_helpers/ajax_helpers'
-], function ($, Backbone, _, Team, InstructorToolsView, TeamUtils, TeamSpecHelpers, AjaxHelpers) {
+    'common/js/spec_helpers/ajax_helpers',
+    'common/js/spec_helpers/page_helpers'
+], function ($, Backbone, _, Team, InstructorToolsView, TeamUtils, TeamSpecHelpers, AjaxHelpers, PageHelpers) {
     'use strict';
 
     describe('Instructor Tools', function () {
@@ -37,6 +38,7 @@ define([
 
         beforeEach(function () {
             setFixtures('<div id="page-prompt"></div>');
+            PageHelpers.preventBackboneChangingUrl();
             spyOn(Backbone.history, 'navigate');
             spyOn(TeamUtils, 'showMessage');
             view = createInstructorTools().render();

lms/djangoapps/teams/static/teams/js/spec/views/topic_teams_spec.js

@@ -4,8 +4,10 @@ define([
     'teams/js/collections/team_membership',
     'teams/js/views/topic_teams',
     'teams/js/spec_helpers/team_spec_helpers',
-    'common/js/spec_helpers/ajax_helpers'
-], function (Backbone, TeamCollection, TeamMembershipCollection, TopicTeamsView, TeamSpecHelpers, AjaxHelpers) {
+    'common/js/spec_helpers/ajax_helpers',
+    'common/js/spec_helpers/page_helpers'
+], function (Backbone, TeamCollection, TeamMembershipCollection, TopicTeamsView, TeamSpecHelpers,
+             AjaxHelpers, PageHelpers) {
     'use strict';
     describe('Topic Teams View', function () {
         var createTopicTeamsView = function(options) {
@@ -39,6 +41,7 @@ define([
 
         beforeEach(function () {
             setFixtures('<div class="teams-container"></div>');
+            PageHelpers.preventBackboneChangingUrl();
         });
 
         it('can render itself', function () {