Factored out fake-timer code into a separate class and moved it to head.js.

services/sync/tests/unit/head_first.js

@@ -41,6 +41,33 @@ function loadInSandbox(aUri) {
   return sandbox;
 }
 
+function FakeTimerService() {
+  Cu.import("resource://weave/util.js");
+
+  this.callbackQueue = [];
+
+  var self = this;
+
+  this.__proto__ = {
+    makeTimerForCall: function FTS_makeTimerForCall(cb) {
+      // Just add the callback to our queue and we'll call it later, so
+      // as to simulate a real nsITimer.
+      self.callbackQueue.push(cb);
+      return "fake nsITimer";
+    },
+    processCallback: function FTS_processCallbacks() {
+      var cb = self.callbackQueue.pop();
+      if (cb) {
+        cb();
+        return true;
+      }
+      return false;
+    }
+  };
+
+  Utils.makeTimerForCall = self.makeTimerForCall;
+};
+
 function initTestLogging() {
   Cu.import("resource://weave/log4moz.js");
 

services/sync/tests/unit/test_async.js

@@ -2,17 +2,10 @@ Cu.import("resource://weave/util.js");
 Cu.import("resource://weave/async.js");
 
 function run_test() {
-  var callbackQueue = [];
+  var fts = new FakeTimerService();
 
   Function.prototype.async = Async.sugar;
 
-  Utils.makeTimerForCall = function fake_makeTimerForCall(cb) {
-    // Just add the callback to our queue and we'll call it later, so
-    // as to simulate a real nsITimer.
-    callbackQueue.push(cb);
-    return "fake nsITimer";
-  };
-
   var onCompleteCalled = false;
 
   function onComplete() {
@@ -31,9 +24,7 @@ function run_test() {
     // Ensure that 'this' is set properly.
     do_check_eq(this.sampleProperty, true);
 
-    // Simulate the calling of an asynchronous function that will call
-    // our callback.
-    callbackQueue.push(self.cb);
+    fts.makeTimerForCall(self.cb);
     yield;
 
     timesYielded++;
@@ -45,15 +36,11 @@ function run_test() {
 
   do_check_eq(timesYielded, 1);
 
-  let func = callbackQueue.pop();
-  do_check_eq(typeof func, "function");
-  func();
+  do_check_true(fts.processCallback());
 
   do_check_eq(timesYielded, 2);
 
-  func = callbackQueue.pop();
-  do_check_eq(typeof func, "function");
-  func();
+  do_check_true(fts.processCallback());
 
-  do_check_eq(callbackQueue.length, 0);
+  do_check_false(fts.processCallback());
 }