Bug 983301 Add a test for FetchEvent.respondWith(5). r=bz

dom/workers/test/serviceworkers/fetch/fetch_tests.js

@@ -96,6 +96,11 @@ fetchXHR('nonresponse2.txt', null, function(xhr) {
   finish();
 });
 
+fetchXHR('nonpromise.txt', null, function(xhr) {
+  my_ok(xhr.status == 0, "load should not complete");
+  finish();
+});
+
 fetchXHR('headers.txt', function(xhr) {
   my_ok(xhr.status == 200, "load should be successful");
   my_ok(xhr.responseText == "1", "request header checks should have passed");

dom/workers/test/serviceworkers/fetch_event_worker.js

@@ -76,6 +76,17 @@ onfetch = function(ev) {
     ev.respondWith(Promise.resolve({}));
   }
 
+  else if (ev.request.url.includes("nonpromise.txt")) {
+    try {
+      // This should coerce to Promise(5) instead of throwing
+      ev.respondWith(5);
+    } catch (e) {
+      // test is expecting failure, so return a success if we get a thrown
+      // exception
+      ev.respondWith(new Response('respondWith(5) threw ' + e));
+    }
+  }
+
   else if (ev.request.url.includes("headers.txt")) {
     var ok = true;
     ok &= ev.request.headers.get("X-Test1") == "header1";