Add support for writing unit tests for Mojo-backed apps/extensions APIs.

extensions/test/data/api_test_base_unittest.js

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var test = require('test').binding;
+
+var tests = test.runTests([
+  function testEnvironment() {
+    test.assertTrue(!!$Array);
+    test.assertTrue(!!$Function);
+    test.assertTrue(!!$JSON);
+    test.assertTrue(!!$Object);
+    test.assertTrue(!!$RegExp);
+    test.assertTrue(!!$String);
+    test.assertTrue(!!privates);
+    test.assertTrue(!!define);
+    test.assertTrue(!!require);
+    test.assertTrue(!!requireNative);
+    test.assertTrue(!!requireAsync);
+    test.assertEq(undefined, chrome.runtime.lastError);
+    test.assertEq(undefined, chrome.extension.lastError);
+    test.succeed();
+  },
+  function testPromisesRun() {
+    Promise.resolve().then(test.callbackPass());
+  },
+  function testCommonModulesAreAvailable() {
+    var binding = require('binding');
+    var binding = require('sendRequest');
+    var binding = require('lastError');

[not at google - send to devlin, 2014/07/18 15:09:14]

by re-assigning binding each time aren't you nullifying lines 28-29?

[Sam McNally, 2014/07/21 03:56:28]

Done.

+    test.assertTrue(!!binding);
+    test.succeed();
+  },
+  function testMojoModulesAreAvailable() {
+    Promise.all([
+      requireAsync('mojo/public/js/bindings/connection'),
+      requireAsync('mojo/public/js/bindings/core'),
+      requireAsync('content/public/renderer/service_provider'),
+    ]).then(test.callback(function(modules) {
+      var connection = modules[0];
+      var core = modules[1];
+      var serviceProvider = modules[2];
+      test.assertTrue(!!connection.Connection);
+      test.assertTrue(!!core.createMessagePipe);
+      test.assertTrue(!!serviceProvider.connectToService);
+    }));
+  },
+])
+for (var testName in tests) {
+  exports[testName] = tests[testName];
+}