With providers split into bundles, the test injector is now able to
use providers for a given bundle. Suggested provider lists for tests are
available in `angular2/platform/testing/<platform>`.
Change the providers for a test suite using `setBaseTestProviders`. This
should be done once at the start of the test suite, before any test cases
run.
BREAKING CHANGE: Tests are now required to use `setBaseTestProviders`
to set up. Assuming your tests are run on a browser, setup would change
as follows.
Before:
```js
// Somewhere in test setup
import {BrowserDomAdapter} from 'angular2/src/platform/browser/browser_adapter';
BrowserDomAdapter.makeCurrent
```
After:
```js
// Somewhere in the test setup
import {setBaseTestProviders} from 'angular2/testing';
import {
  TEST_BROWSER_PLATFORM_PROVIDERS,
  TEST_BROWSER_APPLICATION_PROVIDERS
} from 'angular2/platform/testing/browser';
setBaseTestProviders(TEST_BROWSER_PLATFORM_PROVIDERS,
                     TEST_BROWSER_APPLICATION_PROVIDERS);
```
Closes #5351, Closes #5585
Closes #5975
		
	
Contains helpers to run unit tests for angular2 components and injectables,
backed by the package:test library.
Usage
Update the dev dependencies in your pubspec.yaml to include the angular testing
and test packages:
dev_dependencies:
  test: '^0.12.6'
  angular2_testing: any
  
Then in your test files, use angular2_testing helpers in place of setUp and test:
import 'package:test/test.dart';
import 'package:angular2_testing/angular2_testing.dart';
void main() {
  // This must be called at the beginning of your tests.
  initAngularTests();
  // Initialize the injection tokens you will use in your tests.
  setUpProviders(() => [provide(MyToken, useValue: 'my string'), TestService]);
  // You can then get tokens from the injector via ngSetUp and ngTest.
  ngSetUp((TestService testService) {
    testService.initialize();
  });
  ngTest('can grab injected values', (@Inject(MyToken) token, TestService testService) {
    expect(token, equals('my string'));
    expect(testService.status, equals('ready'));
  });
}
Examples
A sample test is available in test/angular2_testing_test.dart.