Issue 5249 - Implement :-abp-contains()

chrome/content/elemHideEmulation.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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
  * 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 Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 /* globals filterToRegExp */
 
 "use strict";
 
 const abpSelectorRegexp = /:-abp-([\w-]+)\(/i;
 
+let reportError = () => {};
+
 function splitSelector(selector)
 {
   if (selector.indexOf(",") == -1)
     return [selector];
 
   let selectors = [];
   let start = 0;
   let level = 0;
   let sep = "";
 
@@ skipping 37 matching lines @@
       return i + 1;
   return 0;
 }
 
 function makeSelector(node, selector)
 {
   if (!node.parentElement)
   {
     let newSelector = ":root";
     if (selector)
-      newSelector += " > ";
-    return newSelector + selector;
+      newSelector += " > " + selector;
+    return newSelector;
   }
   let idx = positionInParent(node);
   if (idx > 0)
   {
     let newSelector = `${node.tagName}:nth-child(${idx})`;
     if (selector)
-      newSelector += " > ";
-    return makeSelector(node.parentElement, newSelector + selector);
+      newSelector += " > " + selector;
+    return makeSelector(node.parentElement, newSelector);
   }
 
   return selector;
 }
 
-function parseSelectorContent(content)
+function parseSelectorContent(content, startIndex)
 {
   let parens = 1;
   let quote = null;
-  let i;
-  for (i = 0; i < content.length; i++)
+  let i = startIndex;
+  for (; i < content.length; i++)
   {
     let c = content[i];
     if (c == "\\")
     {
       // Ignore escaped characters
       i++;
     }
     else if (quote)
     {
       if (c == quote)
         quote = null;
     }
     else if (c == "'" || c == '"')
       quote = c;
     else if (c == "(")
       parens++;
     else if (c == ")")
     {
       parens--;
       if (parens == 0)
         break;
     }
   }
 
   if (parens > 0)
     return null;
-  return {text: content.substr(0, i), end: i};
-}
-
-/** Parse the selector
- * @param {string} selector the selector to parse
- * @param {Number} level the depth level. 0 is top
- * @return {Object} selectors is an array of objects,
- * or null in case of errors. hide is true if we'll hide
- * elements instead of styles..
+  return {text: content.substring(startIndex, i), end: i};
+}
+
+/** Stringified style objects
+ * @typedef {Object} StringifiedStyle
+ * @property {string} style CSS style represented by a string.
+ * @property {string[]} subSelectors selectors the CSS properties apply to.
  */
-function parseSelector(selector, level = 0)
-{
-  if (selector.length == 0)
-    return {selectors: [], hide: false};
-
-  let match = abpSelectorRegexp.exec(selector);
-  if (!match)
-    return {selectors: [new PlainSelector(selector)], hide: false};
-
-  let hide = false;
-  let selectors = [];
-  let suffixStart = match.index;
-  if (suffixStart > 0)
-    selectors.push(new PlainSelector(selector.substr(0, match.index)));
-
-  let startIndex = match.index + match[0].length;
-  let content = parseSelectorContent(selector.substr(startIndex));
-  if (content == null)
-  {
-    console.error(new SyntaxError("Failed parsing AdBlock Plus " +
-                                  `selector ${selector}, didn't ` +
-                                  "find closing parenthesis."));
-    return {selectors: null, hide: false};
-  }
-  if (match[1] == "properties")
-    selectors.push(new PropsSelector(content.text));
-  else if (match[1] == "has")
-  {
-    let hasSelector = new HasSelector(content.text);
-    if (!hasSelector.valid())
-      return {selectors: null, hide: false};
-    selectors.push(hasSelector);
-    hide = true;
-  }
-  else if (match[1] == "contains")
-  {
-    selectors.push(new ContainsSelector(content.text));
-    hide = true;
-  }
-  else
-  {
-    // this is an error, can't parse selector.
-    console.error(new SyntaxError("Failed parsing AdBlock Plus " +
-                                  `selector ${selector}, invalid ` +
-                                  `pseudo-class -abp-${match[1]}().`));
-    return {selectors: null, hide: false};
-  }
-
-  suffixStart = startIndex + content.end + 1;
-
-  let suffix = parseSelector(selector.substr(suffixStart), level);
-  if (suffix.selectors == null)
-    return {selectors: null, hide: false};
-
-  selectors.push(...suffix.selectors);
-  hide |= suffix.hide;
-
-  return {selectors, hide};
-}
-
-function stringifyStyle(style)
+
+/**
+ * Produce a string representation of the stylesheet entry.
+ * @param {CSSStyleRule} rule the CSS style rule.
+ * @return {StringifiedStyle} the stringified style.
+ */
+function stringifyStyle(rule)
 {
   let styles = [];
-  for (let i = 0; i < style.length; i++)
-  {
-    let property = style.item(i);
-    let value = style.getPropertyValue(property);
-    let priority = style.getPropertyPriority(property);
-    styles.push(property + ": " + value + (priority ? " !" + priority : "") +
-                ";");
+  for (let i = 0; i < rule.style.length; i++)
+  {
+    let property = rule.style.item(i);
+    let value = rule.style.getPropertyValue(property);
+    let priority = rule.style.getPropertyPriority(property);
+    styles.push(`${property}: ${value}${priority ? " !" + priority : ""};`);
   }
   styles.sort();
-  return styles.join(" ");
+  return {
+    style: styles.join(" "),
+    subSelectors: splitSelector(rule.selectorText)
+  };
 }
 
 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))
     yield* evaluate(chain, index + 1, selector, element, styles);
 }
 
 function PlainSelector(selector)
 {
   this._selector = selector;
 }
 
 PlainSelector.prototype = {
   /**
    * Generator function returning a pair of selector
    * string and subtree.
    * @param {string} prefix the prefix for the selector.
    * @param {Node} subtree the subtree we work on.
-   * @param {Array} styles the stringified stylesheet objects.
+   * @param {StringifiedStyle[]} styles the stringified style objects.
    */
   *getSelectors(prefix, subtree, styles)
   {
     yield [prefix + this._selector, subtree];
   }
 };
 
 const incompletePrefixRegexp = /[\s>+~]$/;
 
-function HasSelector(selector, level = 0)
-{
-  let inner = parseSelector(selector, level + 1);
-  this._innerSelectors = inner ? inner.selectors : null;
+function HasSelector(selectors)
+{
+  this._innerSelectors = selectors;
 }
 
 HasSelector.prototype = {
-  valid()
-  {
-    return this._innerSelectors != null;
-  },
+  requiresHiding: true,
 
   *getSelectors(prefix, subtree, styles)
   {
     for (let element of this.getElements(prefix, subtree, styles))
       yield [makeSelector(element, ""), element];
   },
 
   /**
    * Generator function returning selected elements.
    * @param {string} prefix the prefix for the selector.
    * @param {Node} subtree the subtree we work on.
-   * @param {Array} styles the stringified stylesheet objects.
+   * @param {StringifiedStyle[]} styles the stringified style objects.
    */
   *getElements(prefix, subtree, styles)
   {
     let actualPrefix = (!prefix || incompletePrefixRegexp.test(prefix)) ?
         prefix + "*" : prefix;
     let elements = subtree.querySelectorAll(actualPrefix);
     for (let element of elements)
     {
       let newPrefix = makeSelector(element, "");
       let iter = evaluate(this._innerSelectors, 0, newPrefix + " ",
                           element, styles);
       for (let selector of iter)
         // we insert a space between the two. It becomes a no-op if selector
         // doesn't have a combinator
         if (subtree.querySelector(selector))
           yield element;
     }
   }
 };
 
 function ContainsSelector(textContent)
 {
   this._text = textContent;
 }
 
 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 = subtree.querySelectorAll(actualPrefix);
     for (let element of elements)
-      if (element.textContent == this._text)
+      if (element.textContent.includes(this._text))
         yield element;
   }
 };
 
 function PropsSelector(propertyExpression)
 {
   let regexpString;
   if (propertyExpression.length >= 2 && propertyExpression[0] == "/" &&
       propertyExpression[propertyExpression.length - 1] == "/")
   {
     regexpString = propertyExpression.slice(1, -1)
       .replace("\\x7B ", "{").replace("\\x7D ", "}");
   }
   else
     regexpString = filterToRegExp(propertyExpression);
 
   this._regexp = new RegExp(regexpString, "i");
 }
 
 PropsSelector.prototype = {
+  preferHideWithSelector: true,
+
   *findPropsSelectors(styles, prefix, regexp)
   {
     for (let style of styles)
       if (regexp.test(style.style))
         for (let subSelector of style.subSelectors)
           yield prefix + subSelector;
   },
 
   *getSelectors(prefix, subtree, styles)
   {
@@ skipping 18 matching lines @@
     {
       return new URL(stylesheet.href).origin == this.window.location.origin;
     }
     catch (e)
     {
       // Invalid URL, assume that it is first-party.
       return true;
     }
   },
 
+  /** Parse the selector
+   * @param {string} selector the selector to parse
+   * @return {Array} selectors is an array of objects,
+   * or null in case of errors.
+   */
+  parseSelector(selector)
+  {
+    if (selector.length == 0)
+      return [];
+
+    let match = abpSelectorRegexp.exec(selector);
+    if (!match)
+      return [new PlainSelector(selector)];
+
+    let selectors = [];
+    if (match.index > 0)
+      selectors.push(new PlainSelector(selector.substr(0, match.index)));
+
+    let startIndex = match.index + match[0].length;
+    let content = parseSelectorContent(selector, startIndex);
+    if (!content)
+    {
+      this.window.console.error(
+        new SyntaxError("Failed to parse Adblock Plus " +
+                        `selector ${selector} ` +
+                        "due to unmatched parentheses."));
+      return null;
+    }
+    if (match[1] == "properties")
+      selectors.push(new PropsSelector(content.text));
+    else if (match[1] == "has")
+    {
+      let hasSelectors = this.parseSelector(content.text);
+      if (hasSelectors == null)
+        return null;
+      selectors.push(new HasSelector(hasSelectors));
+    }
+    else if (match[1] == "contains")
+      selectors.push(new ContainsSelector(content.text));
+    else
+    {
+      // this is an error, can't parse selector.
+      this.window.console.error(
+        new SyntaxError("Failed to parse Adblock Plus " +
+                        `selector ${selector}, invalid ` +
+                        `pseudo-class :-abp-${match[1]}().`));
+      return null;
+    }
+
+    let suffix = this.parseSelector(selector.substr(content.end + 1));
+    if (suffix == null)
+      return null;
+
+    selectors.push(...suffix);
+
+    if (selectors.length == 1 && selectors[0] instanceof ContainsSelector)
+    {
+      this.window.console.error(
+        new SyntaxError("Failed to parse Adblock Plus " +
+                        `selector ${selector}, can't ` +
+                        "have a lonely :-abp-contains()."));
+      return null;
+    }
+    return selectors;
+  },
+
   addSelectors(stylesheets)
   {
     let selectors = [];
-    let filters = [];
-
-    let hideElements = [];
-    let filterElements = [];
+    let selectorFilters = [];
+
+    let elements = [];
+    let elementFilters = [];
 
     let cssStyles = [];
 
     for (let stylesheet of stylesheets)
     {
       // Explicitly ignore third-party stylesheets to ensure consistent behavior
       // between Firefox and Chrome.
       if (!this.isSameOrigin(stylesheet))
         continue;
 
       let rules = stylesheet.cssRules;
       if (!rules)
         continue;
 
       for (let rule of rules)
       {
         if (rule.type != rule.STYLE_RULE)
           continue;
 
-        let style = stringifyStyle(rule.style);
-        let subSelectors = splitSelector(rule.selectorText);
-        cssStyles.push({style, subSelectors});
+        cssStyles.push(stringifyStyle(rule));
       }
     }
 
+    let {document} = this.window;
     for (let pattern of this.patterns)
+    {
       for (let selector of evaluate(pattern.selectors,
                                     0, "", document, cssStyles))
-        if (!pattern.hide)
+      {
+        if (pattern.selectors.some(s => s.preferHideWithSelector) &&
+            !pattern.selectors.some(s => s.requiresHiding))
         {
           selectors.push(selector);
-          filters.push(pattern.text);
+          selectorFilters.push(pattern.text);
         }
         else
+        {
           for (let element of document.querySelectorAll(selector))
           {
-            hideElements.push(element);
-            filterElements.push(pattern.text);
+            elements.push(element);
+            elementFilters.push(pattern.text);
           }
-
-    this.addSelectorsFunc(selectors, filters);
-    this.hideElemsFunc(hideElements, filterElements);
+        }
+      }
+    }
+
+    this.addSelectorsFunc(selectors, selectorFilters);
+    this.hideElemsFunc(elements, elementFilters);
   },
 
   onLoad(event)
   {
     let stylesheet = event.target.sheet;
     if (stylesheet)
       this.addSelectors([stylesheet]);
   },
 
   apply()
   {
     this.getFiltersFunc(patterns =>
     {
       this.patterns = [];
       for (let pattern of patterns)
       {
-        let {selectors, hide} = parseSelector(pattern.selector);
+        let selectors = this.parseSelector(pattern.selector);
         if (selectors != null && selectors.length > 0)
-          this.patterns.push({selectors, hide, text: pattern.text});
+          this.patterns.push({selectors, text: pattern.text});
       }
 
       if (this.patterns.length > 0)
       {
         let {document} = this.window;
         this.addSelectors(document.styleSheets);
         document.addEventListener("load", this.onLoad.bind(this), true);
       }
     });
   }
 };