Issue 5063 - [emscripten] Make FilterNotifier calls more efficient

test/filterClasses.js

Index: test/filterClasses.js
===================================================================
--- a/test/filterClasses.js
+++ b/test/filterClasses.js
@@ -25,27 +25,29 @@ let CommentFilter = null;
 let ActiveFilter = null;
 let RegExpFilter = null;
 let BlockingFilter = null;
 let WhitelistFilter = null;
 let ElemHideBase = null;
 let ElemHideFilter = null;
 let ElemHideException = null;
 let ElemHideEmulationFilter = null;
+let FilterNotifier = null;
 
 exports.setUp = function(callback)
 {
   let sandboxedRequire = createSandbox();
   (
     {
       Filter, InvalidFilter, CommentFilter, ActiveFilter, RegExpFilter,
       BlockingFilter, WhitelistFilter, ElemHideBase, ElemHideFilter,
       ElemHideException, ElemHideEmulationFilter
     } = sandboxedRequire("../lib/filterClasses")
   );
+  ({FilterNotifier} = sandboxedRequire("../lib/filterNotifier"));
   callback();
 };
 
 exports.testFromText = function(test)
 {
   let tests = [
     ["!asdf", CommentFilter, "comment"],
     ["asdf", BlockingFilter, "blocking"],
@@ -364,8 +366,66 @@ exports.testElemHideSelector = function(
   for (let [text, selector, selectorDomain] of tests)
   {
     doTest(text, selector, selectorDomain);
     doTest(text.replace("##", "#@#"), selector, selectorDomain);
   }
 
   test.done();
 };
+
+exports.testNotifications = function(test)
+{
+  function checkNotifications(action, expected, message)
+  {
+    let result = null;
+    let listener = (topic, filter, newValue, oldValue) =>
+    {
+      if (result)
+        test.ok(false, "Got more that one notification - " + message);
+      else
+        result = [topic, filter.text, newValue, oldValue];
+    };
+    FilterNotifier.addListener(listener);
+    action();
+    FilterNotifier.removeListener(listener);
+    test.deepEqual(result, expected, message);
+  }
+
+  let filter = Filter.fromText("foobar");
+  checkNotifications(() =>
+  {
+    filter.disabled = true;
+  }, ["filter.disabled", "foobar", true, false], "Disabling filter");
+  checkNotifications(() =>
+  {
+    filter.disabled = true;
+  }, null, "Disabling already disabled filter");
+  checkNotifications(() =>
+  {
+    filter.disabled = false;
+  }, ["filter.disabled", "foobar", false, true], "Enabling filter");
+
+  checkNotifications(() =>
+  {
+    filter.lastHit = 1234;
+  }, ["filter.lastHit", "foobar", 1234, 0], "Changing last filter hit");
+  checkNotifications(() =>
+  {
+    filter.lastHit = 1234;
+  }, null, "Changing last filter hit to same value");
+  checkNotifications(() =>
+  {
+    filter.lastHit = 0;
+  }, ["filter.lastHit", "foobar", 0, 1234], "Resetting last filter hit");
+
+  checkNotifications(() =>
+  {
+    filter.hitCount++;
+  }, ["filter.hitCount", "foobar", 1, 0], "Increasing filter hit counts");
+  checkNotifications(() =>
+  {
+    filter.hitCount = 0;
+  }, ["filter.hitCount", "foobar", 0, 1], "Resetting filter hit counts");
+
+  filter.delete();
+  test.done();
+};