Bug 1147699 - Part 3: Add a test for FetchEvent.request.context when intercepting an image load; r=nsm,bzbarsky

dom/workers/test/serviceworkers/fetch/context/context_test.js

@@ -8,6 +8,10 @@ self.addEventListener("fetch", function(event) {
     var body = event.request.context == "fetch" ?
                "so fetch" : "so unfetch";
     event.respondWith(new Response(body));
+  } else if (event.request.url.indexOf("img.jpg") >= 0) {
+    if (event.request.context == "image") {
+      event.respondWith(fetch("realimg.jpg"));
+    }
   } else {
     // Fail any request that we don't know about.
     event.respondWith(Promise.reject());

dom/workers/test/serviceworkers/fetch/context/index.html

@@ -20,7 +20,22 @@
     });
   }
 
-  testFetch()
+  function testImage() {
+    return new Promise(function(resolve, reject) {
+      var img = document.createElement("img");
+      img.src = "img.jpg";
+      // The service worker will respond with an existing image only if the
+      // Request has the correct context, otherwise the Promise will get
+      // rejected and the test will fail.
+      img.onload = resolve;
+      img.onerror = reject;
+    });
+  }
+
+  Promise.all([
+    testFetch(),
+    testImage(),
+  ])
   .then(function() {
     finish();
   }, function(e) {

dom/workers/test/serviceworkers/mochitest.ini

@@ -30,6 +30,7 @@ support-files =
   fetch/context/register.html
   fetch/context/unregister.html
   fetch/context/context_test.js
+  fetch/context/realimg.jpg
   fetch/https/index.html
   fetch/https/register.html
   fetch/https/unregister.html