feat(bootstraping): application bootstrapping implementation.

Entry-point to bootstrapping is a rootComponent. The bootstrapping
method, uses the component's selector to find the insertion element in
the DOM, and attaches the component in its ShadowRoot.

modules/core/test/application_spec.js

@@ -0,0 +1,97 @@
+import {describe, ddescribe, it, iit, xit, xdescribe, expect, beforeEach} from 'test_lib/test_lib';
+import {bootstrap, appDocumentToken, appElementToken, documentDependentBindings}
+    from 'core/application';
+import {Component} from 'core/annotations/component';
+import {DOM} from 'facade/dom';
+import {ListWrapper} from 'facade/collection';
+import {PromiseWrapper} from 'facade/async';
+import {bind} from 'di/di';
+import {TemplateConfig} from 'core/annotations/template_config';
+
+@Component({
+  selector: 'hello-app',
+  template: new TemplateConfig({
+    inline: '{{greeting}} world!',
+    directives: []
+  })
+})
+class HelloRootCmp {
+  constructor() {
+    this.greeting = 'hello';
+  }
+}
+
+@Component({
+  selector: 'hello-app-2',
+  template: new TemplateConfig({
+    inline: '{{greeting}} world, again!',
+    directives: []
+  })
+})
+class HelloRootCmp2 {
+  constructor() {
+    this.greeting = 'hello';
+  }
+}
+
+export function main() {
+  var fakeDoc, el, el2;
+
+  beforeEach(() => {
+    fakeDoc = DOM.createHtmlDocument();
+    el = DOM.createElement('hello-app', fakeDoc);
+    el2 = DOM.createElement('hello-app-2', fakeDoc);
+    DOM.appendChild(fakeDoc.body, el);
+    DOM.appendChild(fakeDoc.body, el2);
+  });
+
+  function testBindings(appComponentType) {
+    return ListWrapper.concat([bind(appDocumentToken).toValue(fakeDoc),
+    ], documentDependentBindings(appComponentType));
+  }
+
+  describe('bootstrap factory method', () => {
+    it('should throw if no element is found', (done) => {
+      var injectorPromise = bootstrap(HelloRootCmp);
+      PromiseWrapper.then(injectorPromise, null, (reason) => {
+        expect(reason.message).toContain(
+            'The app selector "hello-app" did not match any elements');
+        done();
+      });
+    });
+
+    it('should create an injector promise', () => {
+      var injectorPromise = bootstrap(HelloRootCmp, testBindings(HelloRootCmp));
+      expect(injectorPromise).not.toBe(null);
+    });
+
+    it('should resolve an injector promise and contain bindings', (done) => {
+      var injectorPromise = bootstrap(HelloRootCmp, testBindings(HelloRootCmp));
+      injectorPromise.then((injector) => {
+        expect(injector.get(appElementToken)).toBe(el);
+        done();
+      });
+    });
+
+    it('should display hello world', (done) => {
+      var injectorPromise = bootstrap(HelloRootCmp, testBindings(HelloRootCmp));
+      injectorPromise.then((injector) => {
+        expect(injector.get(appElementToken)
+            .shadowRoot.childNodes[0].nodeValue).toEqual('hello world!');
+        done();
+      });
+    });
+
+    it('should support multiple calls to bootstrap', (done) => {
+      var injectorPromise1 = bootstrap(HelloRootCmp, testBindings(HelloRootCmp));
+      var injectorPromise2 = bootstrap(HelloRootCmp2, testBindings(HelloRootCmp2));
+      PromiseWrapper.all([injectorPromise1, injectorPromise2]).then((injectors) => {
+        expect(injectors[0].get(appElementToken)
+            .shadowRoot.childNodes[0].nodeValue).toEqual('hello world!');
+        expect(injectors[1].get(appElementToken)
+            .shadowRoot.childNodes[0].nodeValue).toEqual('hello world, again!');
+        done();
+      });
+    });
+  });
+}