chore(snackbar): clean up liveAnnouncer msg in tests

src/lib/core/a11y/live-announcer.spec.ts

@@ -24,7 +24,7 @@ describe('MdLiveAnnouncer', () => {
     afterEach(() => {
       // In our tests we always remove the current live element, because otherwise we would have
       // multiple live elements due multiple service instantiations.
-      ariaLiveElement.parentNode.removeChild(ariaLiveElement);
+      announcer._removeLiveElement();
     });
 
     it('should correctly update the announce text', fakeAsync(() => {
@@ -56,6 +56,18 @@ describe('MdLiveAnnouncer', () => {
       expect(ariaLiveElement.textContent).toBe('Hey Google');
       expect(ariaLiveElement.getAttribute('aria-live')).toBe('polite');
     }));
+
+    it('should remove the aria-live element from the DOM', fakeAsync(() => {
+      announcer.announce('Hey Google');
+
+      // This flushes our 100ms timeout for the screenreaders.
+      tick(100);
+
+      announcer._removeLiveElement();
+
+      expect(document.body.querySelector('[aria-live]'))
+          .toBeFalsy('Expected that the aria-live element was remove from the DOM.');
+    }));
   });
 
   describe('with a custom element', () => {

src/lib/core/a11y/live-announcer.ts

@@ -40,6 +40,13 @@ export class MdLiveAnnouncer {
     setTimeout(() => this._liveElement.textContent = message, 100);
   }
 
+  /** Removes the aria-live element from the DOM. */
+  _removeLiveElement() {
+    if (this._liveElement && this._liveElement.parentNode) {
+      this._liveElement.parentNode.removeChild(this._liveElement);
+    }
+  }
+
   private _createLiveElement(): Element {
     let liveEl = document.createElement('div');
 

src/lib/snack-bar/snack-bar.spec.ts

@@ -12,14 +12,16 @@ import {
   ViewContainerRef
 } from '@angular/core';
 import {MdSnackBar, MdSnackBarModule} from './snack-bar';
-import {OverlayContainer} from '../core';
+import {OverlayContainer, MdLiveAnnouncer} from '../core';
 import {MdSnackBarConfig} from './snack-bar-config';
 import {SimpleSnackBar} from './simple-snack-bar';
 
+
 // TODO(josephperrott): Update tests to mock waiting for time to complete for animations.
 
 describe('MdSnackBar', () => {
   let snackBar: MdSnackBar;
+  let liveAnnouncer: MdLiveAnnouncer;
   let overlayContainerElement: HTMLElement;
 
   let testViewContainerRef: ViewContainerRef;
@@ -41,12 +43,14 @@ describe('MdSnackBar', () => {
     TestBed.compileComponents();
   }));
 
-  beforeEach(inject([MdSnackBar], (sb: MdSnackBar) => {
+  beforeEach(inject([MdSnackBar, MdLiveAnnouncer], (sb: MdSnackBar, la: MdLiveAnnouncer) => {
     snackBar = sb;
+    liveAnnouncer = la;
   }));
 
   afterEach(() => {
     overlayContainerElement.innerHTML = '';
+    liveAnnouncer._removeLiveElement();
   });
 
   beforeEach(() => {