Replace autostart behavior with hook to start tests.

Prior to this change, tests automatically started once DOMContentLoaded
fires. This means that there is no obvious mechanism to hook into the
system after boot, but before tests start (e.g. to load lazy engine
assets).

This is a somewhat breaking change, apps will have to update their
`tests/test-helper.js` to properly kick off the tests.

The change is pretty trivial:

```js
// tests/test-helper.js

import { start } from 'ember-cli-qunit';
// ...snip current content...
start();
```

Author: Robert Jackson

addon-test-support/ember-cli-qunit.js

@@ -0,0 +1,126 @@
+import Ember from 'ember';
+import QUnit from 'qunit';
+import { QUnitAdapter } from 'ember-qunit';
+import AbstractTestLoader, {
+  addModuleExcludeMatcher,
+  addModuleIncludeMatcher
+} from 'ember-cli-test-loader/test-support/index';
+
+
+addModuleExcludeMatcher(function(moduleName) {
+  return QUnit.urlParams.nolint &&
+    moduleName.match(/\.(jshint|lint-test)$/);
+});
+
+addModuleIncludeMatcher(function(moduleName) {
+  return moduleName.match(/\.jshint$/);
+});
+
+let moduleLoadFailures = [];
+
+QUnit.done(function() {
+  if (moduleLoadFailures.length) {
+    throw new Error('\n' + moduleLoadFailures.join('\n'));
+  }
+});
+
+export class TestLoader extends AbstractTestLoader {
+  moduleLoadFailure(moduleName, error) {
+    moduleLoadFailures.push(error);
+
+    QUnit.module('TestLoader Failures');
+    QUnit.test(moduleName + ': could not be loaded', function() {
+      throw error;
+    });
+  }
+}
+/**
+   Uses current URL configuration to setup the test container.
+
+   * If `?nocontainer` is set, the test container will be hidden.
+   * If `?dockcontainer` or `?devmode` are set the test container will be
+     absolutely positioned.
+   * If `?devmode` is set, the test container will be made full screen.
+
+   @method setupTestContainer
+ */
+export function setupTestContainer() {
+  let testContainer = document.getElementById('ember-testing-container');
+  if (!testContainer) { return; }
+
+  let params = QUnit.urlParams;
+
+  let containerVisibility = params.nocontainer ? 'hidden' : 'visible';
+  let containerPosition = (params.dockcontainer || params.devmode) ? 'absolute' : 'relative';
+
+  if (params.devmode) {
+    testContainer.className = ' full-screen';
+  }
+
+  testContainer.style.visibility = containerVisibility;
+  testContainer.style.position = containerPosition;
+}
+
+/**
+   Load tests following the default patterns:
+
+   * The module name ends with `-test`
+   * The module name ends with `.jshint`
+
+   Excludes tests that match the following
+   patterns when `?nolint` URL param is set:
+
+   * The module name ends with `.jshint`
+   * The module name ends with `-lint-test`
+
+   @method loadTests
+ */
+export function loadTests() {
+  new TestLoader().loadModules();
+}
+
+/**
+   Instruct QUnit to start the tests.
+   @method startTests
+ */
+export function startTests() {
+  QUnit.start();
+}
+
+/**
+   Sets up the `Ember.Test` adapter for usage with QUnit 2.x.
+
+   @method setupTestAdapter
+ */
+export function setupTestAdapter() {
+  Ember.Test.adapter = QUnitAdapter.create();
+}
+
+/**
+   @method start
+   @param {Object} [options] Options to be used for enabling/disabling behaviors
+   @param {Boolean} [options.loadTests] If `false` tests will not be loaded automatically.
+   @param {Boolean} [options.setupTestContainer] If `false` the test container will not
+   be setup based on `devmode`, `dockcontainer`, or `nocontainer` URL params.
+   @param {Boolean} [options.startTests] If `false` tests will not be automatically started
+   (you must run `QUnit.start()` to kick them off).
+   @param {Boolean} [options.setupTestAdapter] If `false` the default Ember.Test adapter will
+   not be updated.
+ */
+export function start(options = { }) {
+  if (options.loadTests !== false) {
+    loadTests();
+  }
+
+  if (options.setupTestContainer !== false) {
+    setupTestContainer();
+  }
+
+  if (options.setupTestAdapter !== false) {
+    setupTestAdapter();
+  }
+
+  if (options.startTests !== false) {
+    startTests();
+  }
+}

index.js

@@ -44,9 +44,16 @@ module.exports = {
     return path.join(__dirname, 'blueprints');
   },
 
-  treeForAddonTestSupport: function() {
+  // intentionally not calling _super here
+  // to avoid these trees being namespaced into
+  // `ember-cli-qunit/test-support/`
+  treeForAddonTestSupport: function(onDiskAddonTestSupportTree) {
     var MergeTrees = require('broccoli-merge-trees');
-    var tree = new MergeTrees(this._getDependencyTrees());
+    var trees = [].concat(
+      this._getDependencyTrees(),
+      onDiskAddonTestSupportTree
+    );
+    var tree = new MergeTrees(trees);
 
     if (this._shouldPreprocessAddonTestSupport) {
       return this.preprocessJs(tree, {
@@ -88,7 +95,6 @@ module.exports = {
         'vendor/qunit/qunit.css',
         'vendor/qunit-notifications/index.js',
         'vendor/ember-cli-qunit/qunit-configuration.js',
-        'vendor/ember-cli-qunit/test-loader.js'
       ];
 
       var addonOptions = target.options['ember-cli-qunit'];

tests/test-helper.js

@@ -2,5 +2,7 @@ import resolver from './helpers/resolver';
 import {
   setResolver
 } from 'ember-qunit';
+import { start } from 'ember-cli-qunit';
 
 setResolver(resolver);
+start();

vendor/ember-cli-qunit/qunit-configuration.js

@@ -1,6 +1,7 @@
-/* globals jQuery, QUnit */
+/* globals QUnit */
 
 (function() {
+  QUnit.config.autostart = false;
   QUnit.config.urlConfig.push({ id: 'nocontainer', label: 'Hide container'});
   QUnit.config.urlConfig.push({ id: 'nolint', label: 'Disable Linting'});
   QUnit.config.urlConfig.push({ id: 'dockcontainer', label: 'Dock container'});
@@ -16,34 +17,4 @@
       }
     });
   }
-
-  function ready(fn) {
-    if (typeof jQuery === 'function') {
-      jQuery(document).ready(fn);
-      return;
-    }
-
-    if (document.readyState != 'loading'){
-      fn();
-    } else {
-      document.addEventListener('DOMContentLoaded', fn);
-    }
-  }
-
-  ready(function() {
-    var testContainer = document.getElementById('ember-testing-container');
-    if (!testContainer) { return; }
-
-    var params = QUnit.urlParams;
-
-    var containerVisibility = params.nocontainer ? 'hidden' : 'visible';
-    var containerPosition = (params.dockcontainer || params.devmode) ? 'absolute' : 'relative';
-
-    if (params.devmode) {
-      testContainer.className = ' full-screen';
-    }
-
-    testContainer.style.visibility = containerVisibility;
-    testContainer.style.position = containerPosition;
-  });
 })();