Ensure scriptlet cache is reset when filtering profile changes

Related issue:
https://github.com/uBlockOrigin/uBlock-issues/issues/2896

TODO: Eventually, distinguish between filtering profile increasing
or decreasing so as to avoid flushing caches when increasing
filtering, which should not affect the scriptlets cache.

src/js/scriptlet-filtering.js

@@ -66,6 +66,10 @@ const scriptletFilteringEngine = {
 const contentScriptRegisterer = new (class {
     constructor() {
         this.hostnameToDetails = new Map();
+        if ( browser.contentScripts === undefined ) { return; }
+        µb.onEvent('filteringBehaviorChanged', ( ) => {
+            this.reset();
+        });
     }
     register(hostname, code) {
         if ( browser.contentScripts === undefined ) { return false; }

src/js/start.js

@@ -453,7 +453,7 @@ if ( selfieIsValid !== true ) {
 
 // Flush memory cache -- unsure whether the browser does this internally
 // when loading a new extension.
-vAPI.net.handlerBehaviorChanged();
+µb.filteringBehaviorChanged();
 
 // Final initialization steps after all needed assets are in memory.
 

src/js/storage.js

@@ -243,7 +243,7 @@ import {
         if ( typeof hs[key] !== typeof hsDefault[key] ) { continue; }
         this.hiddenSettings[key] = hs[key];
     }
-    this.fireDOMEvent('hiddenSettingsChanged');
+    this.fireEvent('hiddenSettingsChanged');
 };
 
 // Note: Save only the settings which values differ from the default ones.
@@ -259,7 +259,7 @@ import {
     });
 };
 
-self.addEventListener('hiddenSettingsChanged', ( ) => {
+µb.onEvent('hiddenSettingsChanged', ( ) => {
     const µbhs = µb.hiddenSettings;
     ubologSet(µbhs.consoleLogLevel === 'info');
     vAPI.net.setOptions({
@@ -364,6 +364,7 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
         netWhitelist: this.arrayFromWhitelist(this.netWhitelist)
     });
     this.netWhitelistModifyTime = Date.now();
+    µb.filteringBehaviorChanged();
 };
 
 /******************************************************************************/
@@ -593,7 +594,7 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
 
     // https://www.reddit.com/r/uBlockOrigin/comments/cj7g7m/
     // https://www.reddit.com/r/uBlockOrigin/comments/cnq0bi/
-    vAPI.net.handlerBehaviorChanged();
+    µb.filteringBehaviorChanged();
 
     vAPI.messaging.broadcast({ what: 'userFiltersUpdated' });
 };
@@ -830,7 +831,7 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
         staticExtFilteringEngine.freeze();
         redirectEngine.freeze();
         vAPI.net.unsuspend();
-        vAPI.net.handlerBehaviorChanged();
+        µb.filteringBehaviorChanged();
 
         vAPI.storage.set({ 'availableFilterLists': µb.availableFilterLists });
 

src/js/ublock.js

@@ -187,10 +187,6 @@ const matchBucket = function(url, hostname, bucket, start) {
         }
     }
     this.saveWhitelist();
-
-    // Flush memory cache
-    vAPI.net.handlerBehaviorChanged();
-
     return true;
 };
 
@@ -425,7 +421,7 @@ const matchBucket = function(url, hostname, bucket, start) {
         redirectEngine.invalidateResourcesSelfie(io);
         this.loadRedirectResources();
     }
-    this.fireDOMEvent('hiddenSettingsChanged');
+    this.fireEvent('hiddenSettingsChanged');
 };
 
 /******************************************************************************/
@@ -526,9 +522,7 @@ const matchBucket = function(url, hostname, bucket, start) {
     cosmeticFilteringEngine.removeFromSelectorCache(srcHostname, 'net');
 
     // Flush memory cache
-    if ( action === 1 ) {
-        vAPI.net.handlerBehaviorChanged();
-    }
+    µb.filteringBehaviorChanged();
 
     if ( details.tabId === undefined ) { return; }
 
@@ -614,7 +608,7 @@ const matchBucket = function(url, hostname, bucket, start) {
         switch ( details.name ) {
             case 'no-scripting':
             case 'no-remote-fonts':
-                vAPI.net.handlerBehaviorChanged();
+                µb.filteringBehaviorChanged();
                 break;
             default:
                 break;
@@ -675,7 +669,7 @@ const matchBucket = function(url, hostname, bucket, start) {
 
     parse();
 
-    self.addEventListener('hiddenSettingsChanged', ( ) => { parse(); });
+    µb.onEvent('hiddenSettingsChanged', ( ) => { parse(); });
 }
 
 /******************************************************************************/

src/js/utils.js

@@ -134,16 +134,32 @@ import µb from './background.js';
 
 /******************************************************************************/
 
-µb.fireDOMEvent = function(name) {
+µb.fireEvent = function(name) {
     if (
-        window instanceof Object &&
-        window.dispatchEvent instanceof Function &&
-        window.CustomEvent instanceof Function
+        self instanceof Object &&
+        self.dispatchEvent instanceof Function &&
+        self.CustomEvent instanceof Function
     ) {
-        window.dispatchEvent(new CustomEvent(name));
+        self.dispatchEvent(new CustomEvent(name));
     }
 };
 
+µb.onEvent = function(name, fn) {
+    if (
+        self instanceof Object &&
+        self.addEventListener instanceof Function
+    ) {
+        self.addEventListener(name, fn);
+    }
+};
+
+/******************************************************************************/
+
+µb.filteringBehaviorChanged = function() {
+    vAPI.net.handlerBehaviorChanged();
+    this.fireEvent('filteringBehaviorChanged');
+};
+
 /******************************************************************************/
 
 // TODO: properly compare arrays