ServiceWorker: Modernize postMessage tests for cleanup

third_party/WebKit/LayoutTests/http/tests/serviceworker/postmessage.html

Index: third_party/WebKit/LayoutTests/http/tests/serviceworker/postmessage.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/serviceworker/postmessage.html b/third_party/WebKit/LayoutTests/http/tests/serviceworker/postmessage.html
index 6e6fade17883af323524b827fd86030a13b7cfd6..a12421bfb5ca24b50e6480513e5b131a00151a52 100644
--- a/third_party/WebKit/LayoutTests/http/tests/serviceworker/postmessage.html
+++ b/third_party/WebKit/LayoutTests/http/tests/serviceworker/postmessage.html
@@ -4,57 +4,52 @@
 <script src="../resources/testharnessreport.js"></script>
 <script src="resources/test-helpers.js"></script>
 <script>
-async_test(function(t) {
+
+promise_test(t => {
+    var script = 'resources/postmessage-worker.js';
     var scope = 'resources/blank.html';
     var registration;
     var worker;
-    service_worker_unregister_and_register(
-        t, 'resources/postmessage-worker.js', scope)
-      .then(function(r) {
+    var port;
+
+    return service_worker_unregister_and_register(t, script, scope)
+      .then(r => {
+          add_completion_callback(() => registration.unregister());

[shimazu, 2016/10/19 01:18:58]

How about using |r| directly?
add_completion_callback(() => r.unregister());

[nhiroki, 2016/10/19 04:00:50]

Done.

           registration = r;
           worker = registration.installing;
+
           var messageChannel = new MessageChannel();
-          messageChannel.port1.onmessage = t.step_func(onMessage);
-          worker.postMessage({port: messageChannel.port2},
-                              [messageChannel.port2]);
-          worker.postMessage({value: 1});
-          worker.postMessage({value: 2});
-          worker.postMessage({done: true});
+          port = messageChannel.port1;
+          return new Promise(resolve => {
+              port.onmessage = resolve;
+              worker.postMessage({port: messageChannel.port2},
+                                 [messageChannel.port2]);

[falken, 2016/10/19 01:55:24]

Why do we send port manually in an object and parse it out on the other end
instead of just using ExtendableMessageEvent.ports[0]?

[nhiroki, 2016/10/19 04:00:50]

Good point. We could use ExtendableMessageEvent.source instead of passing a
MessagePort. Other tests also depend on this worker script and this change
affects them, so I'd like to make this change in a following CL.

[falken, 2016/10/19 04:06:27]

Thanks, yes I think a lot of our tests copy/pasted the original pattern so they
are doing this confusing passing and  parsing of the data object.

+              worker.postMessage({value: 1});
+              worker.postMessage({value: 2});
+              worker.postMessage({done: true});
+            });
         })
-      .catch(unreached_rejection(t));
-
-    var result = [];
-    var expected = [
-      'Acking value: 1',
-      'Acking value: 2',
-    ];
-
-    function onMessage(e) {
-      var message = e.data;
-      if (message === 'quit') {
-        assert_array_equals(result, expected,
-                            'Worker should post back expected values.');
-        postMessageToRedundantWorker();
-      } else {
-        result.push(message);
-      }
-    };
-
-    function postMessageToRedundantWorker() {
-      registration.unregister(scope)
-        .then(function() {
-            return wait_for_state(t, worker, 'redundant');
-          })
-        .then(function() {
-            assert_equals(worker.state, 'redundant');
-            assert_throws(
-              {name:'InvalidStateError'},
-              function() { worker.postMessage(''); },
-              'Calling postMessage on a redundant ServiceWorker should ' +
-                  'throw InvalidStateError.');
-            t.done();
-          })
-        .catch(unreached_rejection(t));
-    }
+      .then(e => {
+          assert_equals(e.data, 'Acking value: 1');
+          return new Promise(resolve => { port.onmessage = resolve; });
+        })
+      .then(e => {
+          assert_equals(e.data, 'Acking value: 2');
+          return new Promise(resolve => { port.onmessage = resolve; });
+        })
+      .then(e => {
+          assert_equals(e.data, 'quit');
+          return registration.unregister(scope);
+        })
+      .then(() => { return wait_for_state(t, worker, 'redundant'); })
+      .then(() => {
+          assert_equals(worker.state, 'redundant');
+          assert_throws(
+            {name:'InvalidStateError'},
+            function() { worker.postMessage(''); },
+            'Calling postMessage on a redundant ServiceWorker should ' +
+                'throw InvalidStateError.');
+        });
   }, 'postMessage to a ServiceWorker (and back via MessagePort)');
+
 </script>