Issue 4394 - Create a filter class for element hiding emulation filters

lib/filterClasses.js

Index: lib/filterClasses.js
===================================================================
--- a/lib/filterClasses.js
+++ b/lib/filterClasses.js
@@ -16,16 +16,17 @@
  */
 
 /**
  * @fileOverview Definition of Filter class and its subclasses.
  */
 
 let {FilterNotifier} = require("filterNotifier");
 let {extend} = require("coreUtils");
+let {elemHideEmulationFeatureMap, filterToRegExp} = require("common");
 
 /**
  * Abstract base class for filters
  *
  * @param {String} text   string representation of the filter
  * @constructor
  */
 function Filter(text)
@@ -90,22 +91,16 @@
  * @type RegExp
  */
 Filter.regexpRegExp = /^(@@)?\/.*\/(?:\$~?[\w\-]+(?:=[^,\s]+)?(?:,~?[\w\-]+(?:=[^,\s]+)?)*)?$/;
 /**
  * Regular expression that options on a RegExp filter should match
  * @type RegExp
  */
 Filter.optionsRegExp = /\$(~?[\w\-]+(?:=[^,\s]+)?(?:,~?[\w\-]+(?:=[^,\s]+)?)*)$/;
-/**
- * Regular expression that CSS property filters should match
- * Properties must not contain " or '
- * @type RegExp
- */
-Filter.csspropertyRegExp = /\[\-abp\-properties=(["'])([^"']+)\1\]/;
 
 /**
  * Creates a filter of correct type from its text representation - does the basic parsing and
  * calls the right constructor then.
  *
  * @param {String} text   as in Filter()
  * @return {Filter}
  */
@@ -171,35 +166,19 @@
     let [, domain, separator, selector] = /^(.*?)(#\@?#?)(.*)$/.exec(text);
     return domain.replace(/\s/g, "") + separator + selector.trim();
   }
   else
     return text.replace(/\s/g, "");
 };
 
 /**
- * Converts filter text into regular expression string
- * @param {String} text as in Filter()
- * @return {String} regular expression representation of filter text
+ * @see filterToRegExp
  */
-Filter.toRegExp = function(text)
-{
-  return text
-    .replace(/\*+/g, "*")        // remove multiple wildcards
-    .replace(/\^\|$/, "^")       // remove anchors following separator placeholder
-    .replace(/\W/g, "\\$&")      // escape special symbols
-    .replace(/\\\*/g, ".*")      // replace wildcards by .*
-    // process separator placeholders (all ANSI characters but alphanumeric characters and _%.-)
-    .replace(/\\\^/g, "(?:[\\x00-\\x24\\x26-\\x2C\\x2F\\x3A-\\x40\\x5B-\\x5E\\x60\\x7B-\\x7F]|$)")
-    .replace(/^\\\|\\\|/, "^[\\w\\-]+:\\/+(?!\\/)(?:[^\\/]+\\.)?") // process extended anchor at expression start
-    .replace(/^\\\|/, "^")       // process anchor at expression start
-    .replace(/\\\|$/, "$")       // process anchor at expression end
-    .replace(/^(\.\*)/, "")      // remove leading wildcards
-    .replace(/(\.\*)$/, "");     // remove trailing wildcards
-}
+Filter.toRegExp = filterToRegExp;
 
 /**
  * Class for invalid filters
  * @param {String} text see Filter()
  * @param {String} reason Reason why this filter is invalid
  * @constructor
  * @augments Filter
  */
@@ -878,17 +857,17 @@
  * Creates an element hiding filter from a pre-parsed text representation
  *
  * @param {String} text         same as in Filter()
  * @param {String} domain       domain part of the text representation (can be empty)
  * @param {Boolean} isException exception rule indicator
  * @param {String} tagName      tag name part (can be empty)
  * @param {String} attrRules    attribute matching rules (can be empty)
  * @param {String} selector     raw CSS selector (can be empty)
- * @return {ElemHideFilter|ElemHideException|CSSPropertyFilter|InvalidFilter}
+ * @return {ElemHideFilter|ElemHideException|ElemHideEmulationFilter|InvalidFilter}
  */
 ElemHideBase.fromText = function(text, domain, isException, tagName, attrRules, selector)
 {
   if (!selector)
   {
     if (tagName == "*")
       tagName = "";
 
@@ -928,27 +907,31 @@
   // Note: The ElemHide.prototype.domainSeparator is duplicated here, if that
   // changes this must be changed too.
   if (domain && /(^|,)~?(,|$)/.test(domain))
     return new InvalidFilter(text, "filter_invalid_domain");
 
   if (isException)
     return new ElemHideException(text, domain, selector);
 
-  let match = Filter.csspropertyRegExp.exec(selector);
-  if (match)
+  let emulatedFeatures = 0;
+  if (selector.indexOf("[-abp-properties") != -1)
+    emulatedFeatures |= ElemHideEmulationFilter.featureMap.PROPERTY_SELECTOR;
+  if (selector.indexOf(":has(") != -1)
+    emulatedFeatures |= ElemHideEmulationFilter.featureMap.HAS_PSEUDO_CLASS;
+
+  if (emulatedFeatures != 0)

[Wladimir Palant, 2016/11/21 11:39:15]

Nit: `if (emulatedFeatures)`?

[Felix Dahlke, 2016/11/21 14:38:59]

Removed along with the feature bitmask.

   {
-    // CSS property filters are inefficient so we need to make sure that
-    // they're only applied if they specify active domains
+    // Element hiding emulation filters are inefficient so we need to make sure
+    // that they're only applied if they specify active domains
     if (!/,[^~][^,.]*\.[^,]/.test("," + domain))
-      return new InvalidFilter(text, "filter_cssproperty_nodomain");
+      return new InvalidFilter(text, "filter_elemhideemulation_nodomain");
 
-    return new CSSPropertyFilter(text, domain, selector, match[2],
-      selector.substr(0, match.index),
-      selector.substr(match.index + match[0].length));
+    return new ElemHideEmulationFilter(text, domain, selector,
+                                       emulatedFeatures);
   }
 
   return new ElemHideFilter(text, domain, selector);
 };
 
 /**
  * Class for element hiding filters
  * @param {String} text see Filter()
@@ -981,74 +964,39 @@
 }
 exports.ElemHideException = ElemHideException;
 
 ElemHideException.prototype = extend(ElemHideBase, {
   type: "elemhideexception"
 });
 
 /**
- * Class for CSS property filters
+ * Class for element hiding emulation filters
  * @param {String} text           see Filter()
  * @param {String} domains        see ElemHideBase()
  * @param {String} selector       see ElemHideBase()
- * @param {String} regexpSource   see CSSPropertyFilter.regexpSource
- * @param {String} selectorPrefix see CSSPropertyFilter.selectorPrefix
- * @param {String} selectorSuffix see CSSPropertyFilter.selectorSuffix
+ * @param {Integer} features      see ElemHideEmulationFilter.features
  * @constructor
  * @augments ElemHideBase
  */
-function CSSPropertyFilter(text, domains, selector, regexpSource,
-  selectorPrefix, selectorSuffix)
+function ElemHideEmulationFilter(text, domains, selector, features)
 {
   ElemHideBase.call(this, text, domains, selector);
 
-  this.regexpSource = regexpSource;
-  this.selectorPrefix = selectorPrefix;
-  this.selectorSuffix = selectorSuffix;
+  this.features = features;
 }
-exports.CSSPropertyFilter = CSSPropertyFilter;
+exports.ElemHideEmulationFilter = ElemHideEmulationFilter;
 
-CSSPropertyFilter.prototype = extend(ElemHideBase, {
-  type: "cssproperty",
+ElemHideEmulationFilter.prototype = extend(ElemHideBase, {
+  type: "elemhideemulation",
 
   /**
-   * Expression from which a regular expression should be generated for matching
-   * CSS properties - for delayed creation of the regexpString property
-   * @type String
+   * Features used in this filter, combination of values from
+   * ElemHideEmulationFilter.featureMap
+   * @type Integer
    */
-  regexpSource: null,
-  /**
-   * Substring of CSS selector before properties for the HTML elements that
-   * should be hidden
-   * @type String
-   */
-  selectorPrefix: null,
-  /**
-   * Substring of CSS selector after properties for the HTML elements that
-   * should be hidden
-   * @type String
-   */
-  selectorSuffix: null,
+  features: 0
+});
 
-  /**
-   * Raw regular expression string to be used when testing CSS properties
-   * against this filter
-   * @type String
-   */
-  get regexpString()
-  {
-    // Despite this property being cached, the getter is called
-    // several times on Safari, due to WebKit bug 132872
-    let prop = Object.getOwnPropertyDescriptor(this, "regexpString");
-    if (prop)
-      return prop.value;
-
-    let regexp;
-    if (this.regexpSource.length >= 2 && this.regexpSource[0] == "/" &&
-        this.regexpSource[this.regexpSource.length - 1] == "/")
-      regexp = this.regexpSource.slice(1, -1);
-    else
-      regexp = Filter.toRegExp(this.regexpSource);
-    Object.defineProperty(this, "regexpString", {value: regexp});
-    return regexp;
-  }
-});
+/**
+ * @see elemHideEmulationFeatureMap
+ */
+ElemHideEmulationFilter.featureMap = elemHideEmulationFeatureMap;