Post a Message from Java to JS

android_webview/javatests/src/org/chromium/android_webview/test/PostMessageTest.java

Index: android_webview/javatests/src/org/chromium/android_webview/test/PostMessageTest.java
diff --git a/android_webview/javatests/src/org/chromium/android_webview/test/PostMessageTest.java b/android_webview/javatests/src/org/chromium/android_webview/test/PostMessageTest.java
index 3be279c9f71d7a65f44febc63d7573c60046c7ba..8dbc89db94b6c3f863bedec4ac91d09d16aa2c6b 100644
--- a/android_webview/javatests/src/org/chromium/android_webview/test/PostMessageTest.java
+++ b/android_webview/javatests/src/org/chromium/android_webview/test/PostMessageTest.java
@@ -19,6 +19,9 @@ import org.chromium.base.test.util.Feature;
 import org.chromium.base.test.util.MinAndroidSdkLevel;
 import org.chromium.net.test.util.TestWebServer;
 
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicBoolean;
+
 /**
  * The tests for content postMessage API.
  */
@@ -141,6 +144,39 @@ public class PostMessageTest extends AwTestBase {
         assertEquals(SOURCE_ORIGIN, mMessageObject.getOrigin());
     }
 
+    @SmallTest
+    @Feature({"AndroidWebView", "Android-PostMessage"})

[mnaganov (inactive), 2015/01/27 13:30:17]

Perhaps, you can just annotate the test with "android.test.UiThreadTest",
because it is effectively a single-threaded test, and it runs on the ui thread
most of the time.

[sgurun-gerrit only, 2015/01/29 03:06:09]

In a UI thread test, how do I make sure the test does not exit before running
the asynchronous callback?

[mnaganov (inactive), 2015/01/29 16:56:20]

Ah, sorry, I missed the fact that all the code is inside "onReceiveValue"
callback.

+    public void testTransferringSamePortTwiceNotAllowed() throws Throwable {
+        loadPage(TEST_PAGE);
+        final AtomicBoolean success = new AtomicBoolean();
+        final CountDownLatch latch = new CountDownLatch(1);
+        runTestOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                ValueCallback<MessageChannel> callback = new ValueCallback<MessageChannel>() {
+                    @Override
+                    public void onReceiveValue(MessageChannel channel) {
+                        mAwContents.postMessageToFrame(null, "1", SOURCE_ORIGIN,
+                                mWebServer.getBaseUrl(),
+                                new MessagePort[]{channel.port2()});
+                        // retransfer the port. This should fail with an exception
+                        try {
+                            mAwContents.postMessageToFrame(null, "2", SOURCE_ORIGIN,
+                                    mWebServer.getBaseUrl(),
+                                    new MessagePort[]{channel.port2()});

[mnaganov (inactive), 2015/01/27 13:30:17]

Perhaps, you can simply insert a call to "fail" after the method, so the test
will fail if there were no exception?

[sgurun-gerrit only, 2015/01/29 03:06:09]

Done.

+                        } catch (IllegalStateException ex) {
+                            success.set(true);
+                        }
+                        latch.countDown();
+                    }
+                };
+                mAwContents.createMessageChannel(callback);
+            }
+        });
+        boolean ignore = latch.await(TIMEOUT, java.util.concurrent.TimeUnit.MILLISECONDS);
+        assertEquals(true, success.get());
+    }
+
     private static class ChannelContainer {
         private boolean mReady;
         private MessageChannel mChannel;
@@ -173,11 +209,10 @@ public class PostMessageTest extends AwTestBase {
         }
     }
 
-    // Verify that a channel can be created and basic full duplex communication
-    // can happen on it.
+    // Verify that messages from JS can be waited on a UI thread.
     @SmallTest
     @Feature({"AndroidWebView", "Android-PostMessage"})
-    public void testCreateChannel() throws Throwable {
+    public void testReceiveMessageInBackgroundThread() throws Throwable {
         loadPage(TEST_PAGE);
         final ChannelContainer channelContainer = new ChannelContainer();
         runTestOnUiThread(new Runnable() {
@@ -218,7 +253,51 @@ public class PostMessageTest extends AwTestBase {
             }
         });
         assertEquals(JS_MESSAGE, channelContainer.getMessage());
-        // TODO(sgurun) verify communication from Java to JS on the created channel
+    }
+
+    private static final String ECHO_PAGE =
+            "<!DOCTYPE html><html><body>"
+            + "    <script type=\"text/javascript\">"
+            + "        onmessage = function (e) {"
+            + "            var myPort = e.ports[0];"
+            + "            myPort.onmessage = function(e) {"
+            + "                myPort.postMessage(e.data); }" // echo recevied message
+            + "        }"
+            + "   </script>"
+            + "</body></html>";
+
+    // Verify that a channel can be created and basic full duplex communication
+    // can happen on it. Do this by sending a message to JS and let it echo'ing
+    // back to Java.
+    @SmallTest
+    @Feature({"AndroidWebView", "Android-PostMessage"})
+    public void testMessageChannel() throws Throwable {
+        final String hello = "HELLO";

[mnaganov (inactive), 2015/01/27 13:30:18]

Would it be better to use separate messages for request and reply, so we can be
sure that we haven't accidentally read back our original message instead of the
reply?

[sgurun-gerrit only, 2015/01/29 03:06:08]

Done. that would be a very sad bug :)

+        final ChannelContainer channelContainer = new ChannelContainer();
+        loadPage(ECHO_PAGE);
+        runTestOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                ValueCallback<MessageChannel> callback = new ValueCallback<MessageChannel>() {
+                    @Override
+                    public void onReceiveValue(MessageChannel channel) {
+                        channel.port1().setMessageHandler(new MessagePort.MessageHandler() {
+                            @Override
+                            public void onMessage(String message) {
+                                channelContainer.setMessage(message);
+                            }
+                        });
+                        mAwContents.postMessageToFrame(null, WEBVIEW_MESSAGE, SOURCE_ORIGIN,
+                                mWebServer.getBaseUrl(), new MessagePort[]{channel.port2()});
+                        channel.port1().postMessage(hello, null);
+                    }
+                };
+                mAwContents.createMessageChannel(callback);
+            }
+        });
+        // wait for the asynchronous response from JS
+        channelContainer.waitForMessage();
+        assertEquals(hello, channelContainer.getMessage());
     }
 
     private static final String WORKER_MESSAGE = "from_worker";