feat(button): add first real unit test

src/components/button/button.spec.ts

@@ -11,7 +11,10 @@ import {
   beforeEach,
 } from 'angular2/testing';
 import {provide, Component} from 'angular2/core';
+import {DebugElement} from "angular2/core";
+
 import {MdButton} from './button';
+import {AsyncTestFn} from "angular2/testing";
 
 
 describe('MdButton', () => {
@@ -19,18 +22,25 @@ describe('MdButton', () => {
 
   beforeEach(inject([TestComponentBuilder], (tcb: TestComponentBuilder) => { builder = tcb; }));
 
-  it('should ...', () => {
-    return builder.createAsync(MdButton).then((fixture) => {
-      fixture.detectChanges();
+  describe('button[md-button]', () => {
+    it('should handle a click on the button', (done: () => void) => {
+      return builder.createAsync(TestApp).then((fixture) => {
+        let testComponent = fixture.debugElement.componentInstance;
+        let buttonDebugElement = getChildDebugElement(fixture.debugElement, 'button');
+
+        buttonDebugElement.nativeElement.click();
+        expect(testComponent.clickCount).toBe(1);
+        done();
+      });
     });
+
   });
-
-
-
-
 });
 
-
+/** Gets a child DebugElement by tag name. */
+function getChildDebugElement(parent: DebugElement, tagName: string): DebugElement {
+  return parent.query(debugEl => debugEl.nativeElement.tagName.toLowerCase() == tagName);
+}
 
 /** Test component that contains an MdButton. */
 @Component({