Browser side of ServiceWorker requestSyncEvents() function

content/test/data/service_worker/sync.js

Index: content/test/data/service_worker/sync.js
diff --git a/content/test/data/service_worker/sync.js b/content/test/data/service_worker/sync.js
index 993e771778a505bc5ff78dedbe29a9d5655026fd..a2b4bffc83dbb7020b38d32c113ebba00178de11 100644
--- a/content/test/data/service_worker/sync.js
+++ b/content/test/data/service_worker/sync.js
@@ -3,8 +3,28 @@
 // found in the LICENSE file.
 
 var code = 404;

[jsbell, 2014/04/03 21:47:34]

The test would be clearer if the global state was `var sawSyncEvent` to avoid
conflating the test's state (was sync fired?) with the signaling mechanism (200
vs 404)

[jkarlin, 2014/04/04 11:59:09]

Done.

+var fetchCount = 0;
+
+// onfetch is a state machine:
+// 1st call returns 404 and calls requestSyncEvents()
+// .. expect sync call here ..
+// 2nd call returns 200 because sync ran and calls requestSyncEvents(false)
+// .. sync doesn't fire ..
+// 3rd call returns 404 and calls requestSyncEvents(true)
+// .. expect sync call here ..
+// 4th call returns 200 because sync ran
 
 this.onfetch = function(event) {
+    if (fetchCount == 0) {

[jsbell, 2014/04/03 21:47:34]

Since the sync event won't fire until after the event.respondWith() is handled
anyway, IMHO it would be clearer to move this all to the end of the function.
Then the function reads in order with (1) respond with previous state, (2) set
up test for the next state.

(Assuming I'm reading it correctly.)

[jkarlin, 2014/04/04 11:59:09]

Done.  Great suggestions, thanks.

+        requestSyncEvents();
+    } else if (fetchCount == 1) {
+        requestSyncEvents(false);
+    } else if (fetchCount == 2) {
+        requestSyncEvents(true);
+    }
+
+    fetchCount += 1;
+
     response = new Response({
         statusCode: code,

[jsbell, 2014/04/03 21:47:34]

And this would be sawSyncEvent ? 200 : 404;

[jkarlin, 2014/04/04 11:59:09]

Done.

         statusText: 'OK',
@@ -15,6 +35,8 @@ this.onfetch = function(event) {
         }
     });
 
+    code = 404;
+
     event.respondWith(new Promise(function(r) {
         setTimeout(function() { r(response); }, 5);
     }));