Introduce Eslint to validate style

This patch introduces eslint and fixes multiple minor code
style issues.

.eslintignore

@@ -0,0 +1,2 @@
+third_party/*
+examples/*

.eslintrc.js

@@ -0,0 +1,124 @@
+module.exports = {
+    "root": true,
+
+    "env": {
+        "node": true,
+        "es6": true
+    },
+
+    "parserOptions": {
+        "ecmaVersion": 8
+    },
+
+    /**
+     * ESLint rules
+     *
+     * All available rules: http://eslint.org/docs/rules/
+     *
+     * Rules take the following form:
+     *   "rule-name", [severity, { opts }]
+     * Severity: 2 == error, 1 == warning, 0 == off.
+     */
+    "rules": {
+        /**
+         * Enforced rules
+         */
+
+
+        // syntax preferences
+        "quotes": [2, "single", {
+            "avoidEscape": true,
+            "allowTemplateLiterals": true
+        }],
+        "semi": 2,
+        "no-extra-semi": 2,
+        "comma-style": [2, "last"],
+        "wrap-iife": [2, "inside"],
+        "spaced-comment": [2, "always", {
+            "markers": ["*"]
+        }],
+        "eqeqeq": [2],
+        "arrow-body-style": [2, "as-needed"],
+        "accessor-pairs": [2, {
+            "getWithoutSet": false,
+            "setWithoutGet": false
+        }],
+        "curly": [2, "multi-or-nest", "consistent"],
+        "new-parens": 2,
+        "func-call-spacing": 2,
+        "arrow-parens": [2, "as-needed"],
+
+        // anti-patterns
+        "no-with": 2,
+        "no-multi-str": 2,
+        "no-caller": 2,
+        "no-implied-eval": 2,
+        "no-labels": 2,
+        "no-new-object": 2,
+        "no-octal-escape": 2,
+        "no-self-compare": 2,
+        "no-shadow-restricted-names": 2,
+        "no-cond-assign": 2,
+        "no-debugger": 2,
+        "no-dupe-keys": 2,
+        "no-duplicate-case": 2,
+        "no-empty-character-class": 2,
+        "no-unreachable": 2,
+        "no-unsafe-negation": 2,
+        "radix": 2,
+        "valid-typeof": 2,
+        "no-unused-vars": [2, { "args": "none", "vars": "local" }],
+
+        // es2015 features
+        "require-yield": 2,
+        "template-curly-spacing": [2, "never"],
+
+        // spacing details
+        "space-infix-ops": 2,
+        "space-in-parens": [2, "never"],
+        "space-before-function-paren": [2, "never"],
+        "no-whitespace-before-property": 2,
+        "keyword-spacing": [2, {
+            "overrides": {
+                "if": {"after": true},
+                "else": {"after": true},
+                "for": {"after": true},
+                "while": {"after": true},
+                "do": {"after": true},
+                "switch": {"after": true},
+                "return": {"after": true}
+            }
+        }],
+        "arrow-spacing": [2, {
+            "after": true,
+            "before": true
+        }],
+
+        // file whitespace
+        "no-multiple-empty-lines": [2, {"max": 2}],
+        "no-mixed-spaces-and-tabs": 2,
+        "no-trailing-spaces": 2,
+        "linebreak-style": [ 2, "unix" ],
+
+        /**
+         * Disabled, aspirational rules
+         */
+
+        "indent": [0, 4, { "SwitchCase": 1, "CallExpression": {"arguments": 2}, "MemberExpression": 2 }],
+
+        // brace-style is disabled, as eslint cannot enforce 1tbs as default, but allman for functions
+        "brace-style": [0, "allman", { "allowSingleLine": true }],
+
+        // key-spacing is disabled, as some objects use value-aligned spacing, some not.
+        "key-spacing": [0, {
+            "beforeColon": false,
+            "afterColon": true,
+            "align": "value"
+        }],
+        // quote-props is diabled, as property quoting styles are too varied to enforce.
+        "quote-props": [0, "as-needed"],
+
+        // no-implicit-globals will prevent accidental globals
+        "no-implicit-globals": [0]
+    }
+};

install.js

@@ -16,7 +16,6 @@
 
 var Downloader = require('./utils/ChromiumDownloader');
 var revision = require('./package').puppeteer.chromium_revision;
-var fs = require('fs');
 var ProgressBar = require('progress');
 
 // Do nothing if the revision is already downloaded.

lib/.eslintrc.js

@@ -0,0 +1,16 @@
+module.exports = {
+    "extends": "../.eslintrc.js",
+    /**
+     * ESLint rules
+     *
+     * All available rules: http://eslint.org/docs/rules/
+     *
+     * Rules take the following form:
+     *   "rule-name", [severity, { opts }]
+     * Severity: 2 == error, 1 == warning, 0 == off.
+     */
+    "rules": {
+        "no-console": [2, { "allow": ["warn", "error", "assert", "timeStamp", "time", "timeEnd"] }],
+        "no-debugger": 0,
+    }
+};

lib/Browser.js

@@ -130,13 +130,12 @@ function waitForChromeResponsive(remoteDebuggingPort) {
         path: '/json/list'
     };
     var probeTimeout = 100;
-    var probeAttempt = 1;
     sendRequest();
     return promise;
 
     function sendRequest() {
         var req = http.request(options, res => {
-            fulfill()
+            fulfill();
         });
         req.on('error', e => setTimeout(sendRequest, probeTimeout));
         req.end();

lib/Page.js

@@ -208,10 +208,8 @@ class Page extends EventEmitter {
 
     _handleException(exceptionDetails) {
         var stack = [];
-        if (exceptionDetails.stackTrace) {
+        if (exceptionDetails.stackTrace)
             stack = exceptionDetails.stackTrace.callFrames.map(cf => cf.url);
-        }
-        var stackTrace = exceptionDetails.stackTrace;
         this.emit(Page.Events.Exception, exceptionDetails.exception.description, stack);
     }
 
@@ -545,7 +543,7 @@ function convertPrintParameterToInches(parameter) {
         throw new Error('printToPDF Cannot handle parameter type: ' + (typeof parameter));
     }
     return pixels / 96;
-};
+}
 
 Page.Events = {
     Alert: 'alert',

lib/helpers.js

@@ -87,4 +87,4 @@ var helpers = module.exports = {
             code += `\n//# sourceURL=${sourceURL}`;
         return code;
     }
-}
+};

phantomjs/Phantom.js

@@ -121,13 +121,13 @@ module.exports.create = function(context, scriptPath) {
          */
         loadModule: function(moduleSource, filename) {
             var code = [
-                "(function(require, exports, module) {\n",
+                '(function(require, exports, module) {\n',
                 moduleSource,
-                "\n}.call({},",
-                "require.cache['" + filename + "']._getRequire(),",
-                "require.cache['" + filename + "'].exports,",
-                "require.cache['" + filename + "']",
-                "));"
+                '\n}.call({},',
+                'require.cache[\'' + filename + '\']._getRequire(),',
+                'require.cache[\'' + filename + '\'].exports,',
+                'require.cache[\'' + filename + '\']',
+                '));'
             ].join('');
             vm.runInContext(code, context, {
                 filename: filename,
@@ -136,4 +136,4 @@ module.exports.create = function(context, scriptPath) {
         },
     };
     return phantom;
-}
+};

phantomjs/System.js

@@ -29,7 +29,7 @@ class System {
         this.stdin = new StandardInput(process.stdin);
         this.stdout = new StandardOutput(process.stdout);
         this.stderr = new StandardOutput(process.stderr);
-        this.platform = "phantomjs";
+        this.platform = 'phantomjs';
         this.pid = process.pid;
         this.isSSLSupported = false;
         this.os = {

phantomjs/WebPage.js

@@ -18,10 +18,7 @@ var await = require('./utilities').await;
 var EventEmitter = require('events');
 var fs = require('fs');
 var path = require('path');
-var mime = require('mime');
-
 var PageEvents = require('../lib/Page').Events;
-var ScreenshotTypes = require('../lib/Page').ScreenshotTypes;
 
 var noop = function() { };
 
@@ -42,9 +39,7 @@ class WebPage {
         if (options.viewportSize)
             await(this._page.setSize(options.viewportSize));
 
-        await(this._page.setInPageCallback('callPhantom', (...args) => {
-            return this.onCallback.apply(null, args);
-        }));
+        await(this._page.setInPageCallback('callPhantom', (...args) => this.onCallback.apply(null, args)));
 
         this.clipRect = options.clipRect || {left: 0, top: 0, width: 0, height: 0};
         this.onCallback = null;

phantomjs/WebServer.js

@@ -22,7 +22,7 @@ class WebServer {
         this._server = http.createServer();
         this.objectName = 'WebServer';
         this.listenOnPort = this.listen;
-        this.newRequest = function(req, res) { }
+        this.newRequest = function(req, res) { };
         Object.defineProperty(this, 'port', {
             get: () => {
                 if (!this._server.listening)
@@ -64,10 +64,10 @@ class WebServer {
                 });
             }
             res.header = res.getHeader;
-            res.setHeaders = (headers) => {
+            res.setHeaders = headers => {
                 for (var key in headers)
                     res.setHeader(key, headers[key]);
-            }
+            };
             Object.defineProperty(res, 'statusCode', {
                 enumerable: true,
                 configurable: true,

phantomjs/index.js

@@ -44,7 +44,7 @@ module.exports = {
         context.phantom = Phantom.create(context, scriptPath);
         context.console = console;
         context.window = context;
-        context.WebPage = (options) => new WebPage(browser, scriptPath, options);
+        context.WebPage = options => new WebPage(browser, scriptPath, options);
 
         vm.createContext(context);
 
@@ -67,5 +67,5 @@ module.exports = {
         })(nativeExports);
         return context;
     }
-}
+};
 

phantomjs/utilities.js

@@ -29,5 +29,4 @@ module.exports = {
             throw error;
         return result;
     }
-}
-
+};

utils/check_availability.js

@@ -20,10 +20,10 @@ var https = require('https');
 var OMAHA_PROXY = 'https://omahaproxy.appspot.com/all.json';
 
 var colors = {
-    reset: "\x1b[0m",
-    red: "\x1b[31m",
-    green: "\x1b[32m",
-    yellow: "\x1b[33m"
+    reset: '\x1b[0m',
+    red: '\x1b[31m',
+    green: '\x1b[32m',
+    yellow: '\x1b[33m'
 };
 
 class Table {