Improve presentation of advanced settings page

Specifically:

- Fix exception being thrown when createing an
  empty line

- Syntax-color invalid setting names

- Syntax-color non-default values

src/advanced-settings.html

@@ -27,8 +27,6 @@
 <script src="lib/codemirror/lib/codemirror.js"></script>
 <script src="lib/codemirror/addon/selection/active-line.js"></script>
 
-<script src="js/codemirror/mode/raw-settings.js"></script>
-
 <script src="js/vapi.js"></script>
 <script src="js/vapi-common.js"></script>
 <script src="js/vapi-client.js"></script>

src/js/advanced-settings.js

@@ -25,15 +25,49 @@
 
 /******************************************************************************/
 
-(( ) => {
+{
 // >>>> Start of private namespace
 
 /******************************************************************************/
 
-const noopFunc = function(){};
-
+let defaultSettings = new Map();
 let beforeHash = '';
 
+/******************************************************************************/
+
+CodeMirror.defineMode('raw-settings', function() {
+    let lastSetting = '';
+
+    return {
+        token: function(stream) {
+            if ( stream.sol() ) {
+                const match = stream.match(/\s*\S+/);
+                if ( match !== null ) {
+                    lastSetting = match[0].trim();
+                    if ( defaultSettings.has(lastSetting) ) {
+                        return 'keyword';
+                    }
+                }
+                lastSetting = '';
+                stream.skipToEnd();
+                return 'error';
+            }
+            if ( lastSetting !== '' ) {
+                stream.eatSpace();
+                const match = stream.match(/\S+.*$/);
+                if ( match !== null ) {
+                    if ( match[0] !== defaultSettings.get(lastSetting) ) {
+                        return 'strong';
+                    }
+                }
+                lastSetting = '';
+            }
+            stream.skipToEnd();
+            return null;
+        }
+    };
+});
+
 const cmEditor = new CodeMirror(
     document.getElementById('advancedSettings'),
     {
@@ -49,7 +83,41 @@ uBlockDashboard.patchCodeMirrorEditor(cmEditor);
 /******************************************************************************/
 
 const hashFromAdvancedSettings = function(raw) {
-    return raw.trim().replace(/\s*[\n\r]+\s*/g, '\n').replace(/[ \t]+/g, ' ');
+    const aa = typeof raw === 'string'
+        ? arrayFromString(raw)
+        : arrayFromObject(raw);
+    aa.sort((a, b) => a[0].localeCompare(b[0]));
+    return JSON.stringify(aa);
+};
+
+/******************************************************************************/
+
+const arrayFromObject = function(o) {
+    const out = [];
+    for ( const k in o ) {
+        if ( o.hasOwnProperty(k) === false ) { continue; }
+        out.push([ k, `${o[k]}` ]);
+    }
+    return out;
+};
+
+const arrayFromString = function(s) {
+    const out = [];
+    for ( let line of s.split(/[\n\r]+/) ) {
+        line = line.trim();
+        if ( line === '' ) { continue; }
+        const pos = line.indexOf(' ');
+        let k, v;
+        if ( pos !== -1 ) {
+            k = line.slice(0, pos);
+            v = line.slice(pos + 1);
+        } else {
+            k = line;
+            v = '';
+        }
+        out.push([ k.trim(), v.trim() ]);
+    }
+    return out;
 };
 
 /******************************************************************************/
@@ -64,7 +132,7 @@ const advancedSettingsChanged = (( ) => {
         const changed =
             hashFromAdvancedSettings(cmEditor.getValue()) !== beforeHash;
         uDom.nodeFromId('advancedSettingsApply').disabled = !changed;
-        CodeMirror.commands.save = changed ? applyChanges : noopFunc;
+        CodeMirror.commands.save = changed ? applyChanges : function(){};
     };
 
     return function() {
@@ -78,21 +146,19 @@ cmEditor.on('changes', advancedSettingsChanged);
 /******************************************************************************/
 
 const renderAdvancedSettings = async function(first) {
-    const raw = await vAPI.messaging.send('dashboard', {
+    const details = await vAPI.messaging.send('dashboard', {
         what: 'readHiddenSettings',
     });
-
-    beforeHash = hashFromAdvancedSettings(raw);
+    defaultSettings = new Map(arrayFromObject(details.default));
+    beforeHash = hashFromAdvancedSettings(details.current);
     const pretty = [];
-    const lines = raw.split('\n');
+    const entries = arrayFromObject(details.current);
     let max = 0;
-    for ( const line of lines ) {
-        const pos = line.indexOf(' ');
-        if ( pos > max ) { max = pos; }
+    for ( const [ k ] of entries ) {
+        if ( k.length > max ) { max = k.length; }
     }
-    for ( const line of lines ) {
-        const pos = line.indexOf(' ');
-        pretty.push(' '.repeat(max - pos) + line);
+    for ( const [ k, v ] of entries ) {
+        pretty.push(' '.repeat(max - k.length) + `${k} ${v}`);
     }
     pretty.push('');
     cmEditor.setValue(pretty.join('\n'));
@@ -128,4 +194,4 @@ renderAdvancedSettings(true);
 /******************************************************************************/
 
 // <<<< End of private namespace
-})();
+}

src/js/codemirror/mode/raw-settings.js

@@ -1,37 +0,0 @@
-/*******************************************************************************
-
-    uBlock Origin - a browser extension to block requests.
-    Copyright (C) 2019-present Raymond Hill
-
-    This program is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see {http://www.gnu.org/licenses/}.
-
-    Home: https://github.com/gorhill/uBlock
-*/
-
-/* global CodeMirror */
-
-'use strict';
-
-CodeMirror.defineMode("raw-settings", function() {
-    return {
-        token: function(stream) {
-            if ( stream.sol() ) {
-                stream.match(/\s*\S+/);
-                return 'keyword';
-            }
-            stream.skipToEnd();
-            return null;
-        }
-    };
-});

src/js/messaging.js

@@ -1163,7 +1163,10 @@ const onMessage = function(request, sender, callback) {
         break;
 
     case 'readHiddenSettings':
-        response = µb.stringFromHiddenSettings();
+        response = {
+            current: µb.hiddenSettings,
+            default: µb.hiddenSettingsDefault,
+        };
         break;
 
     case 'restoreUserData':