Testing Routes

Container testing methods and computed properties follow previous patterns shown in Testing Basics because Ember.Route extends Ember.Object.

Testing routes can be done both via application tests or container tests. Application tests will likely provide better coverage for routes because routes are typically used to perform transitions and load data, both of which are tested more easily in full context rather than isolation.

That being said, sometimes it is important to test your routes in a smaller scope. For example, let's say we'd like to have an alert that can be triggered from anywhere within our application. The alert function displayAlert should be put into the ApplicationRoute because all actions and events bubble up to it from sub-routes and controllers.

By default, Ember CLI does not generate a file for its application route. To extend the behavior of the ember application route we will run the command ember generate route application. Ember CLI does however generate an application template, so when asked whether we want to overwrite app/templates/application.hbs we will answer 'n'.

import Route from '@ember/route';
import { action } from '@ember/object';

export default class ApplicationRoute extends Route {
  @action
  displayAlert(text) {
    this._displayAlert(text);
  }

  _displayAlert(text) {
    alert(text);
  }
}

In this route we've separated our concerns: The action displayAlert contains the code that is called when the action is received, and the private function _displayAlert performs the work. While not necessarily obvious here because of the small size of the functions, separating code into smaller chunks (or "concerns") allows it to be more readily isolated for testing, which in turn allows you to catch bugs more easily.

Here is an example of test this route in an isolated test case:

import { module, test } from 'qunit';
import { setupTest } from 'my-app-name/tests/helpers';

let originalAlert;

module('Unit | Route | application', function(hooks) {
  setupTest(hooks);

  hooks.beforeEach(function(assert) {
    originalAlert = window.alert; // store a reference to window.alert
  });

  hooks.afterEach(function(assert) {
    window.alert = originalAlert; // restore window.alert
  });

  test('should display an alert', function(assert) {
    assert.expect(2);

    // get the route instance
    let route = this.owner.lookup('route:application');

    // stub window.alert to perform a qunit test
    const expectedTextFoo = 'foo';
    window.alert = (text) => {
      assert.equal(text, expectedTextFoo, `expect alert to display ${expectedTextFoo}`);
    };

    // call the _displayAlert function which triggers the qunit test above
    route._displayAlert(expectedTextFoo);

    // set up a second stub to perform a test with the actual action
    const expectedTextBar = 'bar';
    window.alert = (text) => {
      assert.equal(text, expectedTextBar, `expected alert to display ${expectedTextBar}`);
    };

    // Now use the routes send method to test the actual action
    route.send('displayAlert', expectedTextBar);
  });
});