Issue 5685 - Pass ESLint

lib/compat.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
  * 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/>.
  */
 
-var window = this;
+"use strict";
+
+let window = this;
 
 //
 // Module framework stuff
 //
 
 function require(module)
 {
   return require.scopes[module];
 }
 require.scopes = {__proto__: null};
 
 function importAll(module, globalObj)

[sergei, 2017/09/18 07:59:05]

It seems this function is not used, could you just remove it?

[hub, 2017/09/18 12:43:05]

Done.

 {
-  var exports = require(module);
-  for (var key in exports)
+  let exports = require(module);
+  for (let key in exports)
     globalObj[key] = exports[key];
 }
 
 const onShutdown = {
   done: false,
-  add: function() {},
-  remove: function() {}
+  add() {},
+  remove() {}
 };
 
 //
 // XPCOM emulation
 //
 
+// nsIHttpChannel is checked against instanceof.
+class nsIHttpChannel
+{
+}
+
 const Components =
-{
-  interfaces:
-  {
-    nsIHttpChannel: function() {},
-    nsITimer: {TYPE_REPEATING_SLACK: 0},
-  },
-  classes:
-  {
-    "@mozilla.org/timer;1":
-    {
-      createInstance: function()
-      {
-        return new FakeTimer();
-      }
+  {
+    interfaces:
+    {
+      nsIHttpChannel,

[hub, 2017/09/15 19:44:00]

This one was a bit of a corner case. eslint style want us to use the "method"
short hand. But this cause to make nsIHttpChannel not be `instanceof
nsIHttpChannel`, causing failures.

So we declare it as an ES6 class.

[sergei, 2017/09/18 07:59:05]

Acknowledged.

+      nsITimer: {TYPE_REPEATING_SLACK: 0}
     },
-  },
-  utils: {
-    reportError: function(e)
-    {
-      console.error(e);
-      console.trace();
+    classes:
+    {
+      "@mozilla.org/timer;1":
+      {
+        createInstance()
+        {
+          return new FakeTimer();
+        }
+      }
     },
-    import: function(resource)
-    {
-      let match = /^resource:\/\/gre\/modules\/(.+)\.jsm$/.exec(resource);
-      let resourceName = match && match[1];
-      if (resourceName && Cu.import.resources.has(resourceName))
-        return {[resourceName]: Cu.import.resources.get(resourceName)};
-      throw new Error("Attempt to import unknown JavaScript module " + resource);
+    utils:
+    {
+      reportError(e)
+      {
+        console.error(e);
+        console.trace();
+      },
+      import(resource)
+      {
+        let match = /^resource:\/\/gre\/modules\/(.+)\.jsm$/.exec(resource);
+        let resourceName = match && match[1];
+        if (resourceName && Cu.import.resources.has(resourceName))
+          return {[resourceName]: Cu.import.resources.get(resourceName)};
+        throw new Error(
+          "Attempt to import unknown JavaScript module " + resource);
+      }
     }
-  },
-};
+  };
 
 const Cc = Components.classes;
 const Ci = Components.interfaces;
 const Cu = Components.utils;
 
 Cu.import.resources = new Map();
 
 Cu.import.resources.set("XPCOMUtils",
-{
-  generateQI: function() {}
-});
+  {
+    generateQI() {}
+  });
 
 //
 // Services.jsm module emulation
 //
 
 Cu.import.resources.set("Services",
-{
-  obs: {
-    addObserver: function() {},
-    removeObserver: function() {}
-  },
-  vc: {
-    compare: function(v1, v2)
-    {
-      function parsePart(s)
-      {
-        if (!s)
-          return parsePart("0");
-
-        var part = {
-          numA: 0,
-          strB: "",
-          numC: 0,
-          extraD: ""
-        };
-
-        if (s === "*")
-        {
-          part.numA = Number.MAX_VALUE;
+  {
+    obs: {
+      addObserver() {},
+      removeObserver() {}
+    },
+    vc: {
+      compare(v1, v2)
+      {
+        function parsePart(s)
+        {
+          if (!s)
+            return parsePart("0");
+
+          let part = {
+            numA: 0,
+            strB: "",
+            numC: 0,
+            extraD: ""
+          };
+
+          if (s === "*")
+          {
+            part.numA = Number.MAX_VALUE;
+            return part;
+          }
+
+          let matches = s.match(/(\d*)(\D*)(\d*)(.*)/);
+          part.numA = parseInt(matches[1], 10) || part.numA;
+          part.strB = matches[2] || part.strB;
+          part.numC = parseInt(matches[3], 10) || part.numC;
+          part.extraD = matches[4] || part.extraD;
+
+          if (part.strB == "+")
+          {
+            part.numA++;
+            part.strB = "pre";
+          }
+
           return part;
         }
 
-        var matches = s.match(/(\d*)(\D*)(\d*)(.*)/);
-        part.numA = parseInt(matches[1], 10) || part.numA;
-        part.strB = matches[2] || part.strB;
-        part.numC = parseInt(matches[3], 10) || part.numC;
-        part.extraD = matches[4] || part.extraD;
-
-        if (part.strB == "+")
-        {
-          part.numA++;
-          part.strB = "pre";
-        }
-
-        return part;
-      }
-
-      function comparePartElement(s1, s2)
-      {
-        if (s1 === "" && s2 !== "")
-          return 1;
-        if (s1 !== "" && s2 === "")
-          return -1;
-        return s1 === s2 ? 0 : (s1 > s2 ? 1 : -1);
-      }
-
-      function compareParts(p1, p2)
-      {
-        var result = 0;
-        var elements = ["numA", "strB", "numC", "extraD"];
-        elements.some(function(element)
-        {
-          result = comparePartElement(p1[element], p2[element]);
+        function comparePartElement(s1, s2)
+        {
+          if (s1 === "" && s2 !== "")
+            return 1;
+          if (s1 !== "" && s2 === "")
+            return -1;
+          return s1 === s2 ? 0 : (s1 > s2 ? 1 : -1);
+        }
+
+        function compareParts(p1, p2)
+        {
+          let result = 0;
+          let elements = ["numA", "strB", "numC", "extraD"];
+          elements.some(element =>
+          {
+            result = comparePartElement(p1[element], p2[element]);
+            return result;
+          });
           return result;
-        });
-        return result;
-      }
-
-      var parts1 = v1.split(".");
-      var parts2 = v2.split(".");
-      for (var i = 0; i < Math.max(parts1.length, parts2.length); i++)
-      {
-        var result = compareParts(parsePart(parts1[i]), parsePart(parts2[i]));
-        if (result)
-          return result;
-      }
-      return 0;
+        }
+
+        let parts1 = v1.split(".");
+        let parts2 = v2.split(".");
+        for (let i = 0; i < Math.max(parts1.length, parts2.length); i++)
+        {
+          let result = compareParts(parsePart(parts1[i]), parsePart(parts2[i]));
+          if (result)
+            return result;
+        }
+        return 0;
+      }
     }
-  }
-});
+  });
 
 function FakeTimer()
 {
 }
 FakeTimer.prototype =
 {
   delay: 0,
   callback: null,
-  initWithCallback: function(callback, delay)
+  initWithCallback(callback, delay)
   {
     this.callback = callback;
     this.delay = delay;
     this.scheduleTimeout();
   },
-  scheduleTimeout: function()
-  {
-    var me = this;
-    setTimeout(function()
+  scheduleTimeout()
+  {
+    setTimeout(() =>
     {
       try
       {
-        me.callback();
-      }
-      catch(e)
+        this.callback();
+      }
+      catch (e)
       {
         Cu.reportError(e);
       }
-      me.scheduleTimeout();
+      this.scheduleTimeout();
     }, this.delay);
   }
 };
 
 //
 // Fake XMLHttpRequest implementation
 //
 
 function XMLHttpRequest()
 {
   this._requestHeaders = {};
   this._loadHandlers = [];
   this._errorHandlers = [];
-};
+}
 XMLHttpRequest.prototype =
 {
   _url: null,
   _requestHeaders: null,
   _responseHeaders: null,
   _loadHandlers: null,
   _errorHandlers: null,
   onload: null,
   onerror: null,
   status: 0,
@@ skipping 14 matching lines @@
     "dnt": true,
     "expect": true,
     "host": true,
     "keep-alive": true,
     "origin": true,
     "referer": true,
     "te": true,
     "trailer": true,
     "transfer-encoding": true,
     "upgrade": true,
-    "via": true,
+    "via": true
   },
   _forbiddenRequestHeadersRe: new RegExp("^(Proxy|Sec)-", "i"),
 
-  _isRequestHeaderAllowed: function(header)
+  _isRequestHeaderAllowed(header)
   {
     if (this._forbiddenRequestHeaders.hasOwnProperty(header.toLowerCase()))
       return false;
     if (header.match(this._forbiddenRequestHeadersRe))
       return false;
 
     return true;
   },
 
-  addEventListener: function(eventName, handler, capture)
-  {
-    var list;
+  addEventListener(eventName, handler, capture)
+  {
+    let list;
     if (eventName == "load")
       list = this._loadHandlers;
     else if (eventName == "error")
       list = this._errorHandlers;
     else
       throw new Error("Event type " + eventName + " not supported");
 
     if (list.indexOf(handler) < 0)
       list.push(handler);
   },
 
-  removeEventListener: function(eventName, handler, capture)
-  {
-    var list;
+  removeEventListener(eventName, handler, capture)
+  {
+    let list;
     if (eventName == "load")
       list = this._loadHandlers;
     else if (eventName == "error")
       list = this._errorHandlers;
     else
       throw new Error("Event type " + eventName + " not supported");
 
-    var index = list.indexOf(handler);
+    let index = list.indexOf(handler);
     if (index >= 0)
       list.splice(index, 1);
   },
 
-  open: function(method, url, async, user, password)
+  open(method, url, async, user, password)
   {
     if (method != "GET")
       throw new Error("Only GET requests are currently supported");
     if (typeof async != "undefined" && !async)
       throw new Error("Sync requests are not supported");
     if (typeof user != "undefined" || typeof password != "undefined")
       throw new Error("User authentification is not supported");
     if (this.readyState != 0)
       throw new Error("Already opened");
 
     this.readyState = 1;
     this._url = url;
   },
 
-  send: function(data)
+  send(data)
   {
     if (this.readyState != 1)
-      throw new Error("XMLHttpRequest.send() is being called before XMLHttpRequest.open()");
+      throw new Error(
+        "XMLHttpRequest.send() is being called before XMLHttpRequest.open()");
     if (typeof data != "undefined" && data)
       throw new Error("Sending data to server is not supported");
 
     this.readyState = 3;
 
-    var onGetDone = function(result)
+    let onGetDone = function(result)
     {
       this.channel.status = result.status;
       this.status = result.responseStatus;
       this.responseText = result.responseText;
       this._responseHeaders = result.responseHeaders;
       this.readyState = 4;
 
       // Notify event listeners
       const NS_OK = 0;
-      var eventName = (this.channel.status == NS_OK ? "load" : "error");
-      var event = {type: eventName};
+      let eventName = (this.channel.status == NS_OK ? "load" : "error");
+      let event = {type: eventName};
 
       if (this["on" + eventName])
         this["on" + eventName].call(this, event);
 
-      var list = this["_" + eventName + "Handlers"];
-      for (var i = 0; i < list.length; i++)
+      let list = this["_" + eventName + "Handlers"];
+      for (let i = 0; i < list.length; i++)
         list[i].call(this, event);
     }.bind(this);

[sergei, 2017/09/18 07:59:05]

Could you also turn this function into the arrow function, so this `bind` is not
required.

[hub, 2017/09/18 12:43:05]

Done.

-    // HACK (#5066): the code checking whether the connection is allowed is temporary,
-    // the actual check should be in the core when we make a decision whether
-    // to update a subscription with current connection or not, thus whether to
-    // even construct XMLHttpRequest object or not.
-    _isSubscriptionDownloadAllowed(function(isAllowed)
+    // HACK (#5066): the code checking whether the connection is
+    // allowed is temporary, the actual check should be in the core
+    // when we make a decision whether to update a subscription with
+    // current connection or not, thus whether to even construct
+    // XMLHttpRequest object or not.
+    _isSubscriptionDownloadAllowed(isAllowed =>
     {
       if (!isAllowed)
       {
         onGetDone({
-          status: 0x804b000d, //NS_ERROR_CONNECTION_REFUSED;
+          status: 0x804b000d, // NS_ERROR_CONNECTION_REFUSED;
           responseStatus: 0
         });
         return;
       }
       window._webRequest.GET(this._url, this._requestHeaders, onGetDone);
-    }.bind(this));
-  },
-
-  overrideMimeType: function(mime)
-  {
-  },
-
-  setRequestHeader: function(name, value)
+    });
+  },
+
+  overrideMimeType(mime)
+  {
+  },
+
+  setRequestHeader(name, value)
   {
     if (this.readyState > 1)
       throw new Error("Cannot set request header after sending");
 
     if (this._isRequestHeaderAllowed(name))
       this._requestHeaders[name] = value;
     else
       console.warn("Attempt to set a forbidden header was denied: " + name);
   },
 
-  getResponseHeader: function(name)
+  getResponseHeader(name)
   {
     name = name.toLowerCase();
     if (!this._responseHeaders || !this._responseHeaders.hasOwnProperty(name))
       return null;
-    else
-      return this._responseHeaders[name];
+    return this._responseHeaders[name];
   },
 
   channel:
   {
     status: -1,
     notificationCallbacks: {},
     loadFlags: 0,
     INHIBIT_CACHING: 0,
     VALIDATE_ALWAYS: 0,
-    QueryInterface: function()
+    QueryInterface()
     {
       return this;
     }
   }
 };
 
-function _isSubscriptionDownloadAllowed(callback) {
+function _isSubscriptionDownloadAllowed(callback)
+{
   // It's a bit hacky, JsEngine interface which is used by FilterEngine does
   // not allow to inject an arbitrary callback, so we use triggerEvent
   // mechanism.
   // Yet one hack (#5039).
-  var allowed_connection_type = require("prefs").Prefs.allowed_connection_type;
-  if (allowed_connection_type == "")
-    allowed_connection_type = null;
-  _triggerEvent("_isSubscriptionDownloadAllowed", allowed_connection_type, callback);
+  let allowedConnectionType = require("prefs").Prefs.allowed_connection_type;
+  if (allowedConnectionType == "")
+    allowedConnectionType = null;
+  _triggerEvent("_isSubscriptionDownloadAllowed", allowedConnectionType,
+                callback);
 }
 
 // Polyfill Array.prototype.find
 // from https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/find
 // https://tc39.github.io/ecma262/#sec-array.prototype.find
-if (!Array.prototype.find) {
-  Object.defineProperty(Array.prototype, 'find', {
-    value: function (predicate) {
-      // 1. Let O be ? ToObject(this value).
-      if (this == null) {
-        throw new TypeError('"this" is null or not defined');
+if (!Array.prototype.find)

[sergei, 2017/09/18 07:59:05]

Is it possible to remove this polyfill? We are already using a newer V8, I would
just remove it.

[hub, 2017/09/18 12:43:05]

Done.

+{
+  Object.defineProperty(Array.prototype, "find",
+    {
+      value(predicate, ...args)
+      {
+        // 1. Let O be ? ToObject(this value).
+        if (this == null)
+        {
+          throw new TypeError("\"this\" is null or not defined");
+        }
+
+        let o = Object(this);
+
+        // 2. Let len be ? ToLength(? Get(O, "length")).
+        let len = o.length >>> 0;
+
+        // 3. If IsCallable(predicate) is false, throw a TypeError exception.
+        if (typeof predicate !== "function")
+        {
+          throw new TypeError("predicate must be a function");
+        }
+
+        // 4. If thisArg was supplied, let T be thisArg; else
+        //    let T be undefined.
+        let thisArg = args[0];
+
+        // 5. Let k be 0.
+        let k = 0;
+
+        // 6. Repeat, while k < len
+        while (k < len)
+        {
+          // a. Let Pk be ! ToString(k).
+          // b. Let kValue be ? Get(O, Pk).
+          // c. Let testResult be ToBoolean(? Call(predicate, T, "kValue,
+          //    k, O")).
+          // d. If testResult is true, return kValue.
+          let kValue = o[k];
+          if (predicate.call(thisArg, kValue, k, o))
+          {
+            return kValue;
+          }
+          // e. Increase k by 1.
+          k++;
+        }
       }
-
-      var o = Object(this);
-
-      // 2. Let len be ? ToLength(? Get(O, "length")).
-      var len = o.length >>> 0;
-
-      // 3. If IsCallable(predicate) is false, throw a TypeError exception.
-      if (typeof predicate !== 'function') {
-        throw new TypeError('predicate must be a function');
-      }
-
-      // 4. If thisArg was supplied, let T be thisArg; else let T be undefined.
-      var thisArg = arguments[1];
-
-      // 5. Let k be 0.
-      var k = 0;
-
-      // 6. Repeat, while k < len
-      while (k < len) {
-        // a. Let Pk be ! ToString(k).
-        // b. Let kValue be ? Get(O, Pk).
-        // c. Let testResult be ToBoolean(? Call(predicate, T, "kValue, k, O")).
-        // d. If testResult is true, return kValue.
-        var kValue = o[k];
-        if (predicate.call(thisArg, kValue, k, o)) {
-          return kValue;
-        }
-        // e. Increase k by 1.
-        k++;
-      }
-    }
-  });
+    });
 }