Issue 6034 - :-abp-contains() accept a regular expression

lib/content/elemHideEmulation.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 153 matching lines @@
   }
   return all ? subtree.querySelectorAll(selector) :
     subtree.querySelector(selector);
 }
 
 function scopedQuerySelectorAll(subtree, selector)
 {
   return scopedQuerySelector(subtree, selector, true);
 }
 
+const regexpRegexp = /^\/(.*)\/([im]*)$/;
+
+/**
+ * Make a regular expression from a text argument. If it can be parsed as a
+ * regular expression, parse it and the flags.
+ * @param {string} text the text argument.
+ * @param {boolean} escape indicate whether we escape curly braces.

[Manish Jethani, 2018/02/20 10:47:10]

escape could be made optional ("?boolean"), then there's no need to pass a value
for the -abp-contains case below.

[hub, 2018/02/20 17:50:18]

Good point, but this is moot in the current patch.

+ * @param {?string} flags the regexp flags passed to the RegExp constructor:
+ * it overrides flags passed in the text argument.
+ * @return {?RegExp} a RegExp object or null in case of error.
+ */
+function makeRegExpParameter(text, escape, flags)
+{
+  let regexpString = null;
+  let match = regexpRegexp.exec(text);
+  if (match)
+  {
+    regexpString =
+      escape ? match[1].replace("\\7B ", "{").replace("\\7D ", "}") : match[1];
+    if (!flags)
+      flags = match[2];
+  }
+  else
+    regexpString = filterToRegExp(text);

[Manish Jethani, 2018/02/20 10:47:10]

This doesn't make sense for the contains filter, does it? It changes the
behavior even. Previously "Adblock*" would not match the string "Adblock Plus"
but rather only the literal string "Adblock*", but now it does. If there's no
slashes around the text, then it's not a regular expression, nor is it an ABP
filter. We should either fall back to a text search like before or convert it to
a regular expression without any special parsing.

e.g. https://gist.github.com/mjethani/93a03a26abc557a4b365

So if it doesn't match regexpRegexp then it should just be regexEscape(text).

[hub, 2018/02/20 17:50:18]

You are totally right. The new patch fixes that.

+
+  try
+  {
+    return new RegExp(regexpString, flags);
+  }
+  catch (e)
+  {
+  }
+  return null;
+}
+
 function* evaluate(chain, index, prefix, subtree, styles)
 {
   if (index >= chain.length)
   {
     yield prefix;
     return;
   }
   for (let [selector, element] of
        chain[index].getSelectors(prefix, subtree, styles))
   {
@@ skipping 72 matching lines @@
             yield element;
         }
         yield null;
       }
     }
   }
 };
 
 function ContainsSelector(textContent)
 {
-  this._text = textContent;
+  this._regexp = makeRegExpParameter(textContent, false);
 }
 
 ContainsSelector.prototype = {
   requiresHiding: true,
 
   *getSelectors(prefix, subtree, stylesheet)
   {
     for (let element of this.getElements(prefix, subtree, stylesheet))
       yield [makeSelector(element, ""), subtree];
   },
 
   *getElements(prefix, subtree, stylesheet)
   {
     let actualPrefix = (!prefix || incompletePrefixRegexp.test(prefix)) ?
         prefix + "*" : prefix;
 
     let elements = scopedQuerySelectorAll(subtree, actualPrefix);
     if (elements)
     {
       for (let element of elements)
       {
-        if (element.textContent.includes(this._text))
+        if (this._regexp && this._regexp.test(element.textContent))
           yield element;
         else
           yield null;
       }
     }
   }
 };
 
 function PropsSelector(propertyExpression)
 {
-  let regexpString;
-  if (propertyExpression.length >= 2 && propertyExpression[0] == "/" &&
-      propertyExpression[propertyExpression.length - 1] == "/")
-  {
-    regexpString = propertyExpression.slice(1, -1)
-      .replace("\\7B ", "{").replace("\\7D ", "}");
-  }
-  else
-    regexpString = filterToRegExp(propertyExpression);
-
-  this._regexp = new RegExp(regexpString, "i");
+  this._regexp = makeRegExpParameter(propertyExpression, true, "i");
 }
 
 PropsSelector.prototype = {
   preferHideWithSelector: true,
   dependsOnStyles: true,
 
   *findPropsSelectors(styles, prefix, regexp)
   {
     for (let style of styles)
-      if (regexp.test(style.style))
+      if (regexp && regexp.test(style.style))
         for (let subSelector of style.subSelectors)
         {
           if (subSelector.startsWith("*") &&
               !incompletePrefixRegexp.test(prefix))
           {
             subSelector = subSelector.substr(1);
           }
           let idx = subSelector.lastIndexOf("::");
           if (idx != -1)
             subSelector = subSelector.substr(0, idx);
@@ skipping 316 matching lines @@
           characterData: true,
           subtree: true
         }
       );
       this.document.addEventListener("load", this.onLoad.bind(this), true);
     }
   }
 };
 
 exports.ElemHideEmulation = ElemHideEmulation;