Issue 5063 - [emscripten] Make FilterNotifier calls more efficient

test/subscriptionClasses.js

Index: test/subscriptionClasses.js
===================================================================
--- a/test/subscriptionClasses.js
+++ b/test/subscriptionClasses.js
@@ -20,26 +20,28 @@
 let {createSandbox} = require("./_common");
 
 let Filter = null;
 let Subscription = null;
 let SpecialSubscription = null;
 let DownloadableSubscription = null;
 let RegularSubscription = null;
 let ExternalSubscription = null;
+let FilterNotifier = null;
 
 exports.setUp = function(callback)
 {
   let sandboxedRequire = createSandbox();
   ({Filter} = sandboxedRequire("../lib/filterClasses"));
   (
     {
       Subscription, SpecialSubscription, DownloadableSubscription
     } = sandboxedRequire("../lib/subscriptionClasses")
   );
+  ({FilterNotifier} = sandboxedRequire("../lib/filterNotifier"));
   callback();
 };
 
 function compareSubscription(test, url, expected, postInit)
 {
   expected.push("[Subscription]")
   let subscription = Subscription.fromURL(url);
   if (postInit)
@@ -249,8 +251,117 @@ exports.testFilterSerialization = functi
   test.equal(subscription.serializeFilters(), "[Subscription filters]\nfilter2\nfilter1\n", "One filter removed");
 
   subscription.delete();
   filter1.delete();
   filter2.delete();
 
   test.done();
 };
+
+exports.testNotifications = function(test)
+{
+  function checkNotifications(action, expected, message)
+  {
+    let result = null;
+    let listener = (topic, subscription, newValue, oldValue) =>
+    {
+      if (result)
+        test.ok(false, "Got more that one notification - " + message);
+      else
+        result = [topic, subscription.url, newValue, oldValue];
+    };
+    FilterNotifier.addListener(listener);
+    action();
+    FilterNotifier.removeListener(listener);
+    test.deepEqual(result, expected, message);
+  }
+
+  let subscription = Subscription.fromURL("http://example.com/");
+  checkNotifications(() =>
+  {
+    subscription.title = "foobar";
+  }, ["subscription.title", "http://example.com/", "foobar", "http://example.com/"], "Changing subscription title");
+  checkNotifications(() =>
+  {
+    subscription.title = "foobar";
+  }, null, "Setting subscription title to same value");
+  checkNotifications(() =>
+  {
+    subscription.title = null;
+  }, ["subscription.title", "http://example.com/", "", "foobar"], "Resetting subscription title");
+
+  checkNotifications(() =>
+  {
+    subscription.disabled = true;
+  }, ["subscription.disabled", "http://example.com/", true, false], "Disabling subscription");
+  checkNotifications(() =>
+  {
+    subscription.disabled = true;
+  }, null, "Disabling already disabled subscription");
+  checkNotifications(() =>
+  {
+    subscription.disabled = false;
+  }, ["subscription.disabled", "http://example.com/", false, true], "Enabling subscription");
+
+  checkNotifications(() =>
+  {
+    subscription.fixedTitle = true;
+  }, ["subscription.fixedTitle", "http://example.com/", true, false], "Marking title as fixed");
+  checkNotifications(() =>
+  {
+    subscription.fixedTitle = false;
+  }, ["subscription.fixedTitle", "http://example.com/", false, true], "Marking title as editable");
+
+  checkNotifications(() =>
+  {
+    subscription.homepage = "http://example.info/";
+  }, ["subscription.homepage", "http://example.com/", "http://example.info/", ""], "Changing subscription homepage");
+  checkNotifications(() =>
+  {
+    subscription.homepage = null;
+  }, ["subscription.homepage", "http://example.com/", "", "http://example.info/"], "Resetting subscription homepage");
+
+  checkNotifications(() =>
+  {
+    // Using a large number that will only fit into double but not int
+    subscription.lastCheck = 123456789012345;
+  }, ["subscription.lastCheck", "http://example.com/", 123456789012345, 0], "Changing subscription.lastCheck");
+  checkNotifications(() =>
+  {
+    subscription.lastCheck = 123456789012345;
+  }, null, "Setting subscription.lastCheck to same value");
+  checkNotifications(() =>
+  {
+    subscription.lastCheck = 0;
+  }, ["subscription.lastCheck", "http://example.com/", 0, 123456789012345], "Resetting subscription.lastCheck");
+
+  checkNotifications(() =>
+  {
+    // Using a large number that will only fit into double but not int
+    subscription.lastDownload = 543210987654321;
+  }, ["subscription.lastDownload", "http://example.com/", 543210987654321, 0], "Changing subscription.lastDownload");
+  checkNotifications(() =>
+  {
+    subscription.lastDownload = 0;
+  }, ["subscription.lastDownload", "http://example.com/", 0, 543210987654321], "Resetting subscription.lastDownload");
+
+  checkNotifications(() =>
+  {
+    subscription.downloadStatus = "ok";
+  }, ["subscription.downloadStatus", "http://example.com/", "ok", ""], "Changing subscription.downloadStatus");
+  checkNotifications(() =>
+  {
+    subscription.downloadStatus = null;
+  }, ["subscription.downloadStatus", "http://example.com/", "", "ok"], "Resetting subscription.downloadStatus");
+
+  checkNotifications(() =>
+  {
+    subscription.errors++;
+  }, ["subscription.errors", "http://example.com/", 1, 0], "Increasing subscription.errors");
+  checkNotifications(() =>
+  {
+    subscription.errors = 0;
+  }, ["subscription.errors", "http://example.com/", 0, 1], "Resetting subscription.erros");
+
+  subscription.delete();
+  test.done();
+};