[ServiceWorker] CacheStorage tests.

LayoutTests/http/tests/serviceworker/resources/worker-test-harness.js

 /*
  * worker-test-harness should be considered a temporary polyfill around
  * testharness.js for supporting Service Worker based tests. It should not be
  * necessary once the test harness is able to drive worker based tests natively.
  * See https://github.com/w3c/testharness.js/pull/82 for status of effort to
  * update upstream testharness.js. Once the upstreaming is complete, tests that
  * reference worker-test-harness should be updated to directly import
  * testharness.js.
  */
 
@@ skipping 66 matching lines @@
 // boilerplate for testing with promises.
 function promise_test(func, name, properties) {
   properties = properties || {};
   var test = async_test(name, properties);
   Promise.resolve(test.step(func, test, test))
     .then(function() { test.done(); })
     .catch(test.step_func(function(value) {
         throw value;
       }));
 }
+
+// Returns promise that fulfills after the provided |promise| is fulfilled. The

[jsbell, 2014/08/15 21:36:13]

nit: Returns a promise...

[asanka, 2014/08/20 03:10:29]

Done.

+// |test| succeeds only if |promise| throws a DOM exception matching |code|. The

[jsbell, 2014/08/15 21:36:13]

I don't believe this needs to be a DOMException, e.g. this works with
'TypeError' which is just a JS type. (testharness's assert_throws is doing the
right thing, but the docs are a little obsolete?)

[asanka, 2014/08/20 03:10:29]

Changed.

+// optional |description| describes the test being performed.
+// E.g.:
+//   expect_promise_throws(
+//       test, new Promise(...), // something that should throw
+//                               // a DOM exception.
+//       'NotFoundError',
+//       'Should throw NotFoundError.');
+function expect_promise_throws(test, promise, code, description) {
+  return promise.then(
+    test.step_func(function() {
+        throw "expect_promise_throws: " + description + " Promise did now throw."

[jsbell, 2014/08/15 21:36:13]

Use assert_unreached or unreached_func?

[jsbell, 2014/08/15 21:36:13]

nit: line length (80 cols)

[asanka, 2014/08/20 03:10:29]

Looks like it's exactly 80?

Also I chose to throw a string here because the resulting error message is
clearer without the additional 'assert_unreached: .... reached unreachable
code.' I can switch to an assert_unreached or unreached_func, but I'm assuming
that longer term we'd want to have something like this in testharness.js.

I also renamed this to assert_promise_throws() and removed the test parameter
for consistency with assert_*().

+      }),
+    test.step_func(function(e) {
+        assert_throws(code, function() { throw e; }, description);
+      }));
+}