Create a MVP version of uBOLite for Firefox

What does not work at the time of commit:

Cosmetic filtering does not work:

The content scripts responsible for cosmetic filtering fail when
trying to inject the stylesheets through document.adoptedStyleSheets,
with the following error message:

  XrayWrapper denied access to property Symbol.iterator
  (reason: object is not safely Xrayable).
  See https://developer.mozilla.org/en-US/docs/Xray_vision for more
  information. ... css-declarative.js:106:8

A possible solution is to inject those content scripts in the
MAIN world. However Firefox scripting API does not support MAIN
world injection at the moment.

Scriptlet-filtering does not work:

Because scriptlet code needs to be injected in the MAIN world,
and this is currently not supported by Firefox's scripting API,
see https://bugzilla.mozilla.org/show_bug.cgi?id=1736575

There is no count badge on the toolbar icon in Firefox, as it
currently does not support the `DNR.setExtensionActionOptions`
method.

Other than the above issues, it does appear uBO is blocking
properly with no error reported in the dev console.

The adoptedStyleSheets issue though is worrisome, as the
cosmetic filtering content scripts were designed with ISOLATED
world injection in mind. Being forced to inject in MAIN world
(when available) make things a bit more complicated as uBO
has to ensure it's global variables do not leak into the page.

Makefile

@@ -5,7 +5,7 @@ run_options := $(filter-out $@,$(MAKECMDGOALS))
 	compare maxcost medcost mincost modifiers record wasm
 
 sources := $(wildcard assets/* assets/*/* dist/version src/* src/*/* src/*/*/* src/*/*/*/*)
-platform := $(wildcard platform/* platform/*/* platform/*/*/* platform/*/*/*/*)
+platform := $(wildcard platform/* platform/*/* platform/*/*/* platform/*/*/*/* platform/*/*/*/*/*)
 assets := dist/build/uAssets
 
 all: chromium firefox npm
@@ -55,8 +55,11 @@ dig: dist/build/uBlock0.dig
 dig-snfe: dig
 	cd dist/build/uBlock0.dig && npm run snfe $(run_options)
 
-mv3: tools/make-mv3.sh $(sources) $(platform)
-	tools/make-mv3.sh
+mv3-chromium: tools/make-mv3.sh $(sources) $(platform)
+	tools/make-mv3.sh chromium
+
+mv3-firefox: tools/make-mv3.sh $(sources) $(platform)
+	tools/make-mv3.sh firefox
 
 mv3-quick: tools/make-mv3.sh $(sources) $(platform)
 	tools/make-mv3.sh quick

platform/mv3/extension/js/background.js

@@ -169,7 +169,9 @@ async function onPermissionsRemoved() {
 
 function onMessage(request, sender, callback) {
 
-    if ( sender.origin !== UBOL_ORIGIN ) { return; }
+    // https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/runtime/MessageSender
+    //   Firefox API does not set `sender.origin`
+    if ( sender.origin !== undefined && sender.origin !== UBOL_ORIGIN ) { return; }
 
     switch ( request.what ) {
 
@@ -304,7 +306,11 @@ async function start() {
         console.log(`Available static rule count: ${count}`);
     });
 
+    // https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest
+    //   Firefox API does not support `dnr.setExtensionActionOptions`
+    if ( dnr.setExtensionActionOptions ) {
         dnr.setExtensionActionOptions({ displayActionCountAsBadgeText: true });
+    }
 }
 
 (async ( ) => {

platform/mv3/extension/js/scripting-manager.js

@@ -353,6 +353,10 @@ function registerDeclarative(context, declarativeDetails) {
 /******************************************************************************/
 
 function registerScriptlet(context, scriptletDetails) {
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=1736575
+    //   `MAIN` world not yet supported in Firefox
+    if ( navigator && navigator.product === 'Gecko' ) { return; }
+
     const { before, filteringModeDetails, rulesetsDetails } = context;
 
     const hasBroadHostPermission =
@@ -427,6 +431,10 @@ function registerScriptlet(context, scriptletDetails) {
 /******************************************************************************/
 
 function registerScriptletEntity(context) {
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=1736575
+    //   `MAIN` world not yet supported in Firefox
+    if ( navigator && navigator.product === 'Gecko' ) { return; }
+
     const { before, filteringModeDetails, rulesetsDetails } = context;
 
     const js = [];

platform/mv3/extension/js/scripting/css-declarative.js

@@ -32,6 +32,7 @@
 /******************************************************************************/
 
 const declarativeImports = self.declarativeImports || [];
+delete self.declarativeImports;
 
 const lookupSelectors = (hn, out) => {
     for ( const { argsList, hostnamesMap } of declarativeImports ) {

platform/mv3/extension/js/scripting/css-generic.js

@@ -30,9 +30,9 @@
 (function uBOL_cssGeneric() {
 
 const genericSelectorMap = self.genericSelectorMap || new Map();
-if ( genericSelectorMap.size === 0 ) { return; }
+delete self.genericSelectorMap;
 
-self.genericSelectorMap = undefined;
+if ( genericSelectorMap.size === 0 ) { return; }
 
 /******************************************************************************/
 

platform/mv3/extension/js/scripting/css-procedural.js

@@ -659,6 +659,7 @@ class ProceduralFilterer {
 /******************************************************************************/
 
 const proceduralImports = self.proceduralImports || [];
+delete self.proceduralImports;
 
 const lookupSelectors = (hn, out) => {
     for ( const { argsList, hostnamesMap } of proceduralImports ) {

platform/mv3/extension/js/scripting/css-specific.entity.js

@@ -34,6 +34,7 @@
 // $rulesetId$
 
 const specificEntityImports = self.specificEntityImports || [];
+delete self.specificEntityImports;
 
 /******************************************************************************/
 
@@ -65,8 +66,6 @@ for ( let i = 0; i < hnpartslen; i++ ) {
     }
 }
 
-self.specificEntityImports = undefined;
-
 if ( selectors.length === 0 ) { return; }
 
 try {

platform/mv3/firefox/background.html

@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>uBlock Origin Background Page</title>
+</head>
+<body>
+<script src="js/background.js" type="module"></script>
+</body>
+</html>

platform/mv3/firefox/manifest.json

@@ -0,0 +1,48 @@
+{
+  "action": {
+    "default_icon": {
+      "16": "img/icon_16.png",
+      "32": "img/icon_32.png",
+      "64": "img/icon_64.png"
+    },
+    "default_popup": "popup.html"
+  },
+  "author": "Raymond Hill",
+  "background": {
+    "page": "background.html"
+  },
+  "browser_specific_settings": {
+    "gecko": {
+      "id": "uBOLite@raymondhill.net",
+      "strict_min_version": "113a1"
+    }
+  },
+  "declarative_net_request": {
+    "rule_resources": [
+    ]
+  },
+  "default_locale": "en",
+  "description": "__MSG_extShortDesc__",
+  "icons": {
+    "16": "img/icon_16.png",
+    "32": "img/icon_32.png",
+    "64": "img/icon_64.png",
+    "128": "img/icon_128.png"
+  },
+  "manifest_version": 3,
+  "name": "__MSG_extName__",
+  "options_ui": {
+      "page": "dashboard.html"
+  },
+  "optional_permissions": [
+    "<all_urls>"
+  ],
+  "permissions": [
+    "activeTab",
+    "declarativeNetRequest",
+    "scripting"
+  ],
+  "short_name": "uBO Lite",
+  "version": "0.1",
+  "web_accessible_resources": []
+}

platform/mv3/make-rulesets.js

@@ -1418,11 +1418,15 @@ async function main() {
     // Patch declarative_net_request key
     manifest.declarative_net_request = { rule_resources: ruleResources };
     // Patch web_accessible_resources key
-    manifest.web_accessible_resources = [{
+    const web_accessible_resources = {
         resources: Array.from(requiredRedirectResources).map(path => `/${path}`),
         matches: [ '<all_urls>' ],
-        use_dynamic_url: true,
-    }];
+    };
+    if ( commandLineArgs.get('platform') === 'chromium' ) {
+        web_accessible_resources.use_dynamic_url = true;
+    }
+    manifest.web_accessible_resources = [ web_accessible_resources ];
+
     // Patch version key
     const now = new Date();
     const yearPart = now.getUTCFullYear() - 2000;

tools/make-mv3.sh

@@ -6,12 +6,32 @@ set -e
 
 echo "*** uBOLite.mv3: Creating extension"
 
-DES="dist/build/uBOLite.mv3"
+PLATFORM="chromium"
 
-if [ "$1" != "quick" ]; then
+for i in "$@"; do
+  case $i in
+    quick)
+      QUICK="yes"
+      shift # past argument=value
+      ;;
+    firefox)
+      PLATFORM="firefox"
+      shift # past argument=value
+      ;;
+    chromium)
+      PLATFORM="chromium"
+      shift # past argument=value
+      ;;
+  esac
+done
+
+DES="dist/build/uBOLite.$PLATFORM"
+
+if [ "$QUICK" != "yes" ]; then
     rm -rf $DES
 fi
 
+
 mkdir -p $DES
 cd $DES
 DES=$(pwd)
@@ -35,17 +55,24 @@ cp src/js/i18n.js $DES/js/
 cp LICENSE.txt $DES/
 
 echo "*** uBOLite.mv3: Copying mv3-specific files"
+if [ "$PLATFORM" = "firefox" ]; then
+    cp platform/mv3/firefox/background.html $DES/
+fi
 cp platform/mv3/extension/*.html $DES/
 cp platform/mv3/extension/css/* $DES/css/
 cp -R platform/mv3/extension/js/* $DES/js/
 cp platform/mv3/extension/img/* $DES/img/
 cp -R platform/mv3/extension/_locales $DES/
 
-if [ "$1" != "quick" ]; then
+if [ "$QUICK" != "yes" ]; then
     echo "*** uBOLite.mv3: Generating rulesets"
     TMPDIR=$(mktemp -d)
     mkdir -p $TMPDIR
-    cp platform/mv3/extension/manifest.json $DES/
+    if [ "$PLATFORM" = "chromium" ]; then
+        cp platform/mv3/chromium/manifest.json $DES/
+    elif [ "$PLATFORM" = "firefox" ]; then
+        cp platform/mv3/firefox/manifest.json $DES/
+    fi
     ./tools/make-nodejs.sh $TMPDIR
     cp platform/mv3/package.json $TMPDIR/
     cp platform/mv3/*.js $TMPDIR/
@@ -55,7 +82,7 @@ if [ "$1" != "quick" ]; then
     mkdir -p $TMPDIR/web_accessible_resources
     cp src/web_accessible_resources/* $TMPDIR/web_accessible_resources/
     cd $TMPDIR
-    node --no-warnings make-rulesets.js output=$DES
+    node --no-warnings make-rulesets.js output=$DES platform="$PLATFORM"
     cd - > /dev/null
     rm -rf $TMPDIR
 fi