fix(autocomplete): handle escape key (#4703)

* Closes the autocomplete panel when pressing escape.
* Switches the autocomplete unit tests to using the common utility for creating fake keyboard events.

src/lib/autocomplete/autocomplete-trigger.ts

@@ -19,7 +19,7 @@ import {PositionStrategy} from '../core/overlay/position/position-strategy';
 import {ConnectedPositionStrategy} from '../core/overlay/position/connected-position-strategy';
 import {Observable} from 'rxjs/Observable';
 import {MdOptionSelectionChange, MdOption} from '../core/option/option';
-import {ENTER, UP_ARROW, DOWN_ARROW} from '../core/keyboard/keycodes';
+import {ENTER, UP_ARROW, DOWN_ARROW, ESCAPE} from '../core/keyboard/keycodes';
 import {Dir} from '../core/rtl/dir';
 import {MdInputContainer} from '../input/input-container';
 import {ScrollDispatcher} from '../core/overlay/scroll/scroll-dispatcher';
@@ -231,7 +231,9 @@ export class MdAutocompleteTrigger implements ControlValueAccessor, OnDestroy {
   }
 
   _handleKeydown(event: KeyboardEvent): void {
-    if (this.activeOption && event.keyCode === ENTER) {
+    if (event.keyCode === ESCAPE && this.panelOpen) {
+      this.closePanel();
+    } else if (this.activeOption && event.keyCode === ENTER) {
       this.activeOption._selectViaInteraction();
       event.preventDefault();
     } else {

src/lib/autocomplete/autocomplete.spec.ts

@@ -16,7 +16,7 @@ import {MdInputModule} from '../input/index';
 import {Dir, LayoutDirection} from '../core/rtl/dir';
 import {FormControl, FormsModule, ReactiveFormsModule} from '@angular/forms';
 import {Subscription} from 'rxjs/Subscription';
-import {ENTER, DOWN_ARROW, SPACE, UP_ARROW} from '../core/keyboard/keycodes';
+import {ENTER, DOWN_ARROW, SPACE, UP_ARROW, ESCAPE} from '../core/keyboard/keycodes';
 import {MdOption} from '../core/option/option';
 import {MdAutocomplete} from './autocomplete';
 import {MdInputContainer} from '../input/input-container';
@@ -758,6 +758,23 @@ describe('MdAutocomplete', () => {
       expect(scrollContainer.scrollTop).toEqual(272, `Expected panel to reveal last option.`);
     }));
 
+    it('should close the panel when pressing escape', async(() => {
+      const trigger = fixture.componentInstance.trigger;
+      const escapeEvent = createKeyboardEvent('keydown', ESCAPE);
+
+      input.focus();
+
+      fixture.whenStable().then(() => {
+        expect(document.activeElement).toBe(input, 'Expected input to be focused.');
+        expect(trigger.panelOpen).toBe(true, 'Expected panel to be open.');
+
+        trigger._handleKeydown(escapeEvent);
+
+        expect(document.activeElement).toBe(input, 'Expected input to continue to be focused.');
+        expect(trigger.panelOpen).toBe(false, 'Expected panel to be closed.');
+      });
+    }));
+
   });
 
   describe('aria', () => {