Issue 4878 - Start using ESLint for adblockpluscore

lib/filterClasses.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 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/>.
  */
 
 "use strict";
 
 /**
  * @fileOverview Definition of Filter class and its subclasses.
  */
 
-let {FilterNotifier} = require("filterNotifier");
-let {extend} = require("coreUtils");
-let {filterToRegExp} = require("common");
+const {FilterNotifier} = require("filterNotifier");
+const {extend} = require("coreUtils");
+const {filterToRegExp} = require("common");
 
 /**
  * Abstract base class for filters
  *
  * @param {string} text   string representation of the filter
  * @constructor
  */
 function Filter(text)
 {
   this.text = text;
@@ skipping 56 matching lines @@
  * @type {RegExp}
  */
 Filter.regexpRegExp = /^(@@)?\/.*\/(?:\$~?[\w-]+(?:=[^,\s]+)?(?:,~?[\w-]+(?:=[^,\s]+)?)*)?$/;
 /**
  * Regular expression that options on a RegExp filter should match
  * @type {RegExp}
  */
 Filter.optionsRegExp = /\$(~?[\w-]+(?:=[^,\s]+)?(?:,~?[\w-]+(?:=[^,\s]+)?)*)$/;
 
 /**
- * Creates a filter of correct type from its text representation -
- * does the basic parsing and calls the right constructor then.
+ * 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}
  */
 Filter.fromText = function(text)
 {
   if (text in Filter.knownFilters)
     return Filter.knownFilters[text];
 
   let ret;
@@ skipping 48 matching lines @@
   // Remove line breaks and such
   text = text.replace(/[^\S ]/g, "");
 
   if (/^\s*!/.test(text))
   {
     // Don't remove spaces inside comments
     return text.trim();
   }
   else if (Filter.elemhideRegExp.test(text))
   {
-    // Special treatment for element hiding filters, right side is
-    // allowed to contain spaces
+    // Special treatment for element hiding filters, right side is allowed to
+    // contain spaces
     let [, domain, separator, selector] = /^(.*?)(#@?#?)(.*)$/.exec(text);
     return domain.replace(/\s/g, "") + separator + selector.trim();
   }
   return text.replace(/\s/g, "");
 };
 
 /**
  * @see filterToRegExp
  */
 Filter.toRegExp = filterToRegExp;
@@ skipping 17 matching lines @@
   type: "invalid",
 
   /**
    * Reason why this filter is invalid
    * @type {string}
    */
   reason: null,
 
   /**
    * See Filter.serialize()
-   * @param {string[]} buffer  buffer to push the serialization results into
+   * @inheritdoc
    */
   serialize(buffer) {}
 });
 
 /**
  * Class for comments
  * @param {string} text see Filter()
  * @constructor
  * @augments Filter
  */
 function CommentFilter(text)
 {
   Filter.call(this, text);
 }
 exports.CommentFilter = CommentFilter;
 
 CommentFilter.prototype = extend(Filter, {
   type: "comment",
 
   /**
    * See Filter.serialize()
-   * @param {string[]} buffer  buffer to push the serialization results into
+   * @inheritdoc
    */
   serialize(buffer) {}
 });
 
 /**
  * Abstract base class for filters that can get hits
- * @param {string} text see Filter()
- * @param {string} [domains] Domains that the filter is restricted to
- *                  separated by domainSeparator e.g. "foo.com|bar.com|~baz.com"
+ * @param {string} text
+ *   see Filter()
+ * @param {string} [domains]
+ *   Domains that the filter is restricted to separated by domainSeparator
+ *   e.g. "foo.com|bar.com|~baz.com"
  * @constructor
  * @augments Filter
  */
 function ActiveFilter(text, domains)
 {
   Filter.call(this, text);
 
   this.domainSource = domains;
 }
 exports.ActiveFilter = ActiveFilter;
@@ skipping 17 matching lines @@
     {
       let oldValue = this._disabled;
       this._disabled = value;
       FilterNotifier.triggerListeners("filter.disabled", this, value, oldValue);
     }
     return this._disabled;
   },
 
   /**
    * Number of hits on the filter since the last reset
-   * @type {Number}
+   * @type {number}
    */
   get hitCount()
   {
     return this._hitCount;
   },
   set hitCount(value)
   {
     if (value != this._hitCount)
     {
       let oldValue = this._hitCount;
       this._hitCount = value;
       FilterNotifier.triggerListeners("filter.hitCount", this, value, oldValue);
     }
     return this._hitCount;
   },
 
   /**
-   * Last time the filter had a hit (in milliseconds since the
-   * beginning of the epoch)
-   * @type {Number}
+   * Last time the filter had a hit (in milliseconds since the beginning of the
+   * epoch)
+   * @type {number}
    */
   get lastHit()
   {
     return this._lastHit;
   },
   set lastHit(value)
   {
     if (value != this._lastHit)
     {
       let oldValue = this._lastHit;
@@ skipping 114 matching lines @@
    * @param {string} [sitekey] public key provided by the document
    * @return {boolean} true in case of the filter being active
    */
   isActiveOnDomain(docDomain, sitekey)
   {
     // Sitekeys are case-sensitive so we shouldn't convert them to
     // upper-case to avoid false positives here. Instead we need to
     // change the way filter options are parsed.
     if (this.sitekeys &&
         (!sitekey || this.sitekeys.indexOf(sitekey.toUpperCase()) < 0))
+    {
       return false;
+    }
 
     // If no domains are set the rule matches everywhere
     if (!this.domains)
       return true;
 
     // If the document has no host name, match only if the filter
     // isn't restricted to specific domains
     if (!docDomain)
       return this.domains[""];
 
@@ skipping 23 matching lines @@
   {
     if (!docDomain || !this.domains || this.domains[""])
       return false;
 
     if (this.ignoreTrailingDot)
       docDomain = docDomain.replace(/\.+$/, "");
     docDomain = docDomain.toUpperCase();
 
     for (let domain in this.domains)
     {
-      if (this.domains[domain] && domain != docDomain &&
-          (domain.length <= docDomain.length ||
-           domain.indexOf("." + docDomain) !=
-             domain.length - docDomain.length - 1))

[Sebastian Noack, 2017/02/21 09:19:31]

Perhaps this rather complex condition is either to understand (and nicer to
read) if you split it up a bit:

  if (this.domains[domain] && domain != docDomain)
  {
    if (domain.length <= docDomain.length)
      return false;

    let pos = domain.indexOf("." + docDomain);
    if (pos != domain.length - docDomain.length - 1)
      return false;
  }

What do you think?

[kzar, 2017/02/21 10:37:01]

Looks much clearer to me, Done.

-        return false;
+      if (this.domains[domain] && domain != docDomain)
+      {
+        if (domain.length <= docDomain.length)
+          return false;
+
+        if (!domain.endsWith("." + docDomain))
+          return false;
+      }
     }
 
     return true;
   },
 
   /**
    * Checks whether this filter is generic or specific
    * @return {boolean}
    */
   isGeneric()
   {
     return !(this.sitekeys && this.sitekeys.length) &&
             (!this.domains || this.domains[""]);
   },
 
   /**
    * See Filter.serialize()
-   * @param {string[]} buffer  buffer to push the serialization results into
+   * @inheritdoc
    */
   serialize(buffer)
   {
     if (this._disabled || this._hitCount || this._lastHit)
     {
       Filter.prototype.serialize.call(this, buffer);
       if (this._disabled)
         buffer.push("disabled=true");
       if (this._hitCount)
         buffer.push("hitCount=" + this._hitCount);
       if (this._lastHit)
         buffer.push("lastHit=" + this._lastHit);
     }
   }
 });
 
 /**
  * Abstract base class for RegExp-based filters
  * @param {string} text see Filter()
- * @param {string} regexpSource filter part that the regular expression should
- *                              be build from
- * @param {Number} [contentType] Content types the filter applies to,
- *                               combination of values from RegExpFilter.typeMap
- * @param {boolean} [matchCase] Defines whether the filter should distinguish
- *                              between lower and upper case letters
- * @param {string} [domains] Domains that the filter is restricted to,
- *                           e.g. "foo.com|bar.com|~baz.com"
- * @param {boolean} [thirdParty] Defines whether the filter should apply to
- *                               third-party or first-party content only
- * @param {string} [sitekeys] Public keys of websites that this filter should
- *                            apply to
+ * @param {string} regexpSource
+ *   filter part that the regular expression should be build from
+ * @param {number} [contentType]
+ *   Content types the filter applies to, combination of values from
+ *   RegExpFilter.typeMap
+ * @param {boolean} [matchCase]
+ *   Defines whether the filter should distinguish between lower and upper case
+ *   letters
+ * @param {string} [domains]
+ *   Domains that the filter is restricted to, e.g. "foo.com|bar.com|~baz.com"
+ * @param {boolean} [thirdParty]
+ *   Defines whether the filter should apply to third-party or first-party
+ *   content only
+ * @param {string} [sitekeys]
+ *   Public keys of websites that this filter should apply to
  * @constructor
  * @augments ActiveFilter
  */
 function RegExpFilter(text, regexpSource, contentType, matchCase, domains,
                       thirdParty, sitekeys)
 {
   ActiveFilter.call(this, text, domains, sitekeys);
 
   if (contentType != null)
     this.contentType = contentType;
@@ skipping 59 matching lines @@
       return prop.value;
 
     let source = Filter.toRegExp(this.regexpSource);
     let regexp = new RegExp(source, this.matchCase ? "" : "i");
     Object.defineProperty(this, "regexp", {value: regexp});
     return regexp;
   },
   /**
    * Content types the filter applies to, combination of values from
    * RegExpFilter.typeMap
-   * @type {Number}
+   * @type {number}
    */
   contentType: 0x7FFFFFFF,
   /**
    * Defines whether the filter should distinguish between lower and
    * upper case letters
    * @type {boolean}
    */
   matchCase: false,
   /**
    * Defines whether the filter should apply to third-party or
@@ skipping 42 matching lines @@
    * @param {boolean} thirdParty should be true if the URL is a third-party
    *                             request
    * @param {string} sitekey public key provided by the document
    * @return {boolean} true in case of a match
    */
   matches(location, typeMask, docDomain, thirdParty, sitekey)
   {
     if (this.contentType & typeMask &&
         (this.thirdParty == null || this.thirdParty == thirdParty) &&
         this.isActiveOnDomain(docDomain, sitekey) && this.regexp.test(location))
+    {
       return true;
+    }
     return false;
   }
 });
 
 // Required to optimize Matcher, see also RegExpFilter.prototype.length
 Object.defineProperty(RegExpFilter.prototype, "0", {
   get() { return this; }
 });
 
 /**
  * Creates a RegExp filter from its text representation
  * @param {string} text   same as in Filter()
- * @return {RegExpFilter}
+ * @return {Filter}
  */
 RegExpFilter.fromText = function(text)
 {
   let blocking = true;
   let origText = text;
   if (text.indexOf("@@") == 0)
   {
     blocking = false;
     text = text.substr(2);
   }
@@ skipping 102 matching lines @@
 RegExpFilter.prototype.contentType &= ~(RegExpFilter.typeMap.DOCUMENT |
                                         RegExpFilter.typeMap.ELEMHIDE |
                                         RegExpFilter.typeMap.POPUP |
                                         RegExpFilter.typeMap.GENERICHIDE |
                                         RegExpFilter.typeMap.GENERICBLOCK);
 
 /**
  * Class for blocking filters
  * @param {string} text see Filter()
  * @param {string} regexpSource see RegExpFilter()
- * @param {Number} contentType see RegExpFilter()
+ * @param {number} contentType see RegExpFilter()
  * @param {boolean} matchCase see RegExpFilter()
  * @param {string} domains see RegExpFilter()
  * @param {boolean} thirdParty see RegExpFilter()
  * @param {string} sitekeys see RegExpFilter()
- * @param {boolean} collapse  defines whether the filter should collapse blocked
- *                            content, can be null
+ * @param {boolean} collapse
+ *   defines whether the filter should collapse blocked content, can be null
  * @constructor
  * @augments RegExpFilter
  */
 function BlockingFilter(text, regexpSource, contentType, matchCase, domains,
                         thirdParty, sitekeys, collapse)
 {
   RegExpFilter.call(this, text, regexpSource, contentType, matchCase, domains,
                     thirdParty, sitekeys);
 
   this.collapse = collapse;
 }
 exports.BlockingFilter = BlockingFilter;
 
 BlockingFilter.prototype = extend(RegExpFilter, {
   type: "blocking",
 
   /**
    * Defines whether the filter should collapse blocked content.
    * Can be null (use the global preference).
    * @type {boolean}
    */
   collapse: null
 });
 
 /**
  * Class for whitelist filters
  * @param {string} text see Filter()
  * @param {string} regexpSource see RegExpFilter()
- * @param {Number} contentType see RegExpFilter()
+ * @param {number} contentType see RegExpFilter()
  * @param {boolean} matchCase see RegExpFilter()
  * @param {string} domains see RegExpFilter()
  * @param {boolean} thirdParty see RegExpFilter()
  * @param {string} sitekeys see RegExpFilter()
  * @constructor
  * @augments RegExpFilter
  */
 function WhitelistFilter(text, regexpSource, contentType, matchCase, domains,
                          thirdParty, sitekeys)
 {
@@ skipping 15 matching lines @@
  *                            hidden
  * @constructor
  * @augments ActiveFilter
  */
 function ElemHideBase(text, domains, selector)
 {
   ActiveFilter.call(this, text, domains || null);
 
   if (domains)
   {
-    this.selectorDomain = domains.replace(/,~[^,]+/g, "").
-      replace(/^~[^,]+,?/, "").toLowerCase();

[Sebastian Noack, 2017/02/21 09:19:30]

I think it's more readable when indented like this:

  this.selectorDomain = domains.replace(/,~[^,]+/g, "")
                               .replace(/^~[^,]+,?/, "").toLowerCase();

[kzar, 2017/02/21 10:37:01]

Done.

+    this.selectorDomain = domains.replace(/,~[^,]+/g, "")
+                                 .replace(/^~[^,]+,?/, "").toLowerCase();
   }
 
   // Braces are being escaped to prevent CSS rule injection.
   this.selector = selector.replace("{", "\\x7B ").replace("}", "\\x7D ");
 }
 exports.ElemHideBase = ElemHideBase;
 
 ElemHideBase.prototype = extend(ActiveFilter, {
   /**
    * @see ActiveFilter.domainSeparator
@@ skipping 15 matching lines @@
    * CSS selector for the HTML elements that should be hidden
    * @type {string}
    */
   selector: null
 });
 
 /**
  * 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 {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|
  *          ElemHideEmulationFilter|InvalidFilter}
  */
 ElemHideBase.fromText = function(text, domain, isException, tagName, attrRules,
                                  selector)
 {
@@ skipping 102 matching lines @@
  */
 function ElemHideEmulationFilter(text, domains, selector)
 {
   ElemHideBase.call(this, text, domains, selector);
 }
 exports.ElemHideEmulationFilter = ElemHideEmulationFilter;
 
 ElemHideEmulationFilter.prototype = extend(ElemHideBase, {
   type: "elemhideemulation"
 });