Merge pull request #1272 from erwinmombay/when-doc-ready

feature(document-state): add `whenDocumentReady` function that returns a promise

extensions/amp-user-notification/0.1/amp-user-notification.js

@@ -21,7 +21,7 @@ import {cidFor} from '../../../src/cid';
 import {getService} from '../../../src/service';
 import {isExperimentOn} from '../../../src/experiments';
 import {log} from '../../../src/log';
-import {onDocumentReady} from '../../../src/document-state';
+import {whenDocumentReady} from '../../../src/document-state';
 import {viewerFor} from '../../../src/viewer';
 import {xhrFor} from '../../../src/xhr';
 
@@ -258,17 +258,10 @@ export class UserNotificationManager {
     /** @private @const {!Viewer} */
     this.viewer_ = viewerFor(this.win_);
 
-    // TODO(erwinm, #1226)
-    // Add `whenDocumentReady` function in document-state
-    // that returns a promise.
-    const documentReadyPromise_ = new Promise(resolve => {
-      onDocumentReady(this.win_.document, resolve);
-    });
-
     /** @private {!Promise} */
     this.managerReadyPromise_ = all([
       this.viewer_.whenVisible(),
-      documentReadyPromise_
+      whenDocumentReady(this.win_.document)
     ]);
 
     /** @private {!Promise} */

src/document-state.js

@@ -52,6 +52,17 @@ export function onDocumentReady(doc, callback) {
   }
 }
 
+/**
+ * Returns a promise that is resolved when document is ready.
+ * @param {!Document} doc
+ * @return {!Promise}
+ */
+export function whenDocumentReady(doc) {
+  return new Promise(resolve => {
+    onDocumentReady(doc, resolve);
+  });
+}
+
 
 /**
  */

test/functional/test-document-state.js

@@ -14,8 +14,9 @@
  * limitations under the License.
  */
 
-import {DocumentState, isDocumentReady, onDocumentReady} from
+import {DocumentState, isDocumentReady, onDocumentReady, whenDocumentReady} from
     '../../src/document-state';
+import {timer} from '../../src/timer';
 import * as sinon from 'sinon';
 
 
@@ -88,6 +89,59 @@ describe('documentReady', () => {
     expect(callback.callCount).to.equal(1);
     expect(eventListeners['readystatechange']).to.equal(undefined);
   });
+
+  describe('whenDocumentReady', () => {
+
+    it('should call callback immediately when ready', () => {
+      testDoc.readyState = 'complete';
+      const spy = sinon.spy();
+      const spy2 = sinon.spy();
+      const spy3 = sinon.spy();
+
+      whenDocumentReady(testDoc).then(spy).then(spy2);
+
+      whenDocumentReady(testDoc).then(spy3);
+
+      expect(spy.callCount).to.equal(0);
+      expect(spy2.callCount).to.equal(0);
+      expect(spy3.callCount).to.equal(0);
+
+      return timer.promise().then(() => {
+        expect(spy.callCount).to.equal(1);
+        expect(spy2.callCount).to.equal(1);
+        expect(spy3.callCount).to.equal(1);
+      });
+    });
+
+    it('should not call callback', () => {
+      const spy = sinon.spy();
+      whenDocumentReady(testDoc).then(spy);
+      expect(spy.callCount).to.equal(0);
+      return timer.promise().then(() => {
+        expect(spy.callCount).to.equal(0);
+      });
+    });
+
+    it('should wait to call callback until ready', () => {
+      testDoc.readyState = 'loading';
+      const callback = sinon.spy();
+      whenDocumentReady(testDoc).then(callback);
+
+      return timer.promise().then(() => {
+        expect(callback.callCount).to.equal(0);
+        expect(eventListeners['readystatechange']).to.not.equal(undefined);
+
+        // Complete
+        testDoc.readyState = 'complete';
+        eventListeners['readystatechange']();
+
+        return timer.promise().then(() => {
+          expect(callback.callCount).to.equal(1);
+          expect(eventListeners['readystatechange']).to.equal(undefined);
+        });
+      });
+    });
+  });
 });