Upgrade linters to ESLint with stricter code style (prebid#1111)

* Upgraded to ESLint with stricter code style, for both sources and tests
* Updated some dependencies and the yarn.lock file

.eslintrc

@@ -0,0 +1,42 @@
+{
+  "env": {
+    "browser": true,
+    "commonjs": true
+  },
+  "extends": "standard",
+  "globals": {
+    "$$PREBID_GLOBAL$$": false
+  },
+  "parserOptions": {
+    "sourceType": "module"
+  },
+  "rules": {
+    "comma-dangle": "off",
+    "semi": "off",
+    "space-before-function-paren": "off",
+
+    // Exceptions below this line are temporary, so that eslint can be added into the CI process.
+    // Violations of these styles should be fixed, and the exceptions removed over time.
+    //
+    // See Issue #1111.
+    "brace-style": "off",
+    "camelcase": "off",
+    "eqeqeq": "off",
+    "import/first": "off",
+    "no-control-regex": "off",
+    "no-mixed-operators": "off",
+    "no-multiple-empty-lines": "off",
+    "no-redeclare": "off",
+    "no-return-assign": "off",
+    "no-throw-literal": "off",
+    "no-undef": "off",
+    "no-unused-vars": "off",
+    "no-use-before-define": "off",
+    "no-useless-call": "off",
+    "no-useless-escape": "off",
+    "one-var": "off",
+    "standard/no-callback-literal": "off",
+    "standard/object-curly-even-spacing": "off",
+    "valid-typeof": "off"
+  }
+}

README.md

@@ -158,9 +158,9 @@ Please **do NOT load Prebid.js inside your adapter**. If you do this, we will re
 
 ### Code Quality
 
-Code quality is defined by `.jscs` and `.jshint` files and errors are reported in the terminal.
+Code quality is defined by `.eslintrc` and errors are reported in the terminal.
 
-If you are contributing code, you should configure your editor with the provided `.jscs` and `.jshint` settings.
+If you are contributing code, you should [configure your editor](http://eslint.org/docs/user-guide/integrations#editors) with the provided `.eslintrc` settings.
 
 ### Unit Testing with Karma
 

gulpfile.js

@@ -1,12 +1,9 @@
-'use strict';
-
-var argv = require('yargs').argv;
 var gulp = require('gulp');
+var argv = require('yargs').argv;
 var gutil = require('gulp-util');
 var connect = require('gulp-connect');
 var webpack = require('webpack-stream');
 var uglify = require('gulp-uglify');
-var jshint = require('gulp-jshint');
 var clean = require('gulp-clean');
 var karma = require('gulp-karma');
 var mocha = require('gulp-mocha');
@@ -16,12 +13,12 @@ var helpers = require('./gulpHelpers');
 var del = require('del');
 var gulpJsdoc2md = require('gulp-jsdoc-to-markdown');
 var concat = require('gulp-concat');
-var jscs = require('gulp-jscs');
 var header = require('gulp-header');
 var zip = require('gulp-zip');
 var replace = require('gulp-replace');
 var shell = require('gulp-shell');
 var optimizejs = require('gulp-optimize-js');
+const eslint = require('gulp-eslint');
 
 var CI_MODE = process.env.NODE_ENV === 'ci';
 var prebid = require('./package.json');
@@ -32,13 +29,13 @@ var analyticsDirectory = '../analytics';
 var port = 9999;
 
 // Tasks
-gulp.task('default', ['clean', 'quality', 'webpack']);
+gulp.task('default', ['clean', 'lint', 'webpack']);
 
-gulp.task('serve', ['clean', 'quality', 'devpack', 'webpack', 'watch', 'test']);
+gulp.task('serve', ['clean', 'lint', 'devpack', 'webpack', 'watch', 'test']);
 
-gulp.task('serve-nw', ['clean', 'quality', 'devpack', 'webpack', 'watch', 'e2etest']);
+gulp.task('serve-nw', ['clean', 'lint', 'devpack', 'webpack', 'watch', 'e2etest']);
 
-gulp.task('run-tests', ['clean', 'quality', 'webpack', 'test', 'mocha']);
+gulp.task('run-tests', ['clean', 'lint', 'webpack', 'test', 'mocha']);
 
 gulp.task('build', ['webpack']);
 
@@ -59,7 +56,7 @@ gulp.task('devpack', function () {
     .pipe(connect.reload());
 });
 
-gulp.task('webpack', function () {
+gulp.task('webpack', ['clean'], function () {
 
   // change output filename if argument --tag given
   if (argv.tag && argv.tag.length) {
@@ -80,7 +77,7 @@ gulp.task('webpack', function () {
 });
 
 //zip up for release
-gulp.task('zip', ['jscs', 'clean', 'webpack'], function () {
+gulp.task('zip', ['clean', 'webpack'], function () {
   return gulp.src(['build/dist/*', 'integrationExamples/gpt/*'])
     .pipe(zip(packageNameVersion + '.zip'))
     .pipe(gulp.dest('./'));
@@ -89,7 +86,7 @@ gulp.task('zip', ['jscs', 'clean', 'webpack'], function () {
 // Karma Continuous Testing
 // Pass your browsers by using --browsers=chrome,firefox,ie9
 // Run CI by passing --watch
-gulp.task('test', function () {
+gulp.task('test', ['clean'], function () {
   var defaultBrowsers = CI_MODE ? ['PhantomJS'] : ['Chrome'];
   var browserArgs = helpers.parseBrowserArgs(argv).map(helpers.toCapitalCase);
 
@@ -137,7 +134,16 @@ gulp.task('test', function () {
     }));
 });
 
-gulp.task('mocha', ['webpack'], function() {
+//
+// Making this task depend on lint is a bit of a hack. The `run-tests` command is the entrypoint for the CI process,
+// and it needs to run all these tasks together. However, the "lint" and "mocha" tasks explode when used in parallel,
+// resulting in some mysterious "ShellJS: internal error TypeError: Cannot read property 'isFile' of undefined"
+// errors.
+//
+// Gulp doesn't support serial dependencies (until gulp 4.0... which is most likely never coming out)... so we have
+// to trick it by declaring 'lint' as a dependency here. See https://github.com/gulpjs/gulp/blob/master/docs/recipes/running-tasks-in-series.md
+//
+gulp.task('mocha', ['webpack', 'lint'], function() {
     return gulp.src(['test/spec/loaders/**/*.js'], { read: false })
         .pipe(mocha({
           reporter: 'spec',
@@ -175,11 +181,11 @@ gulp.task('watch', function () {
     'src/**/*.js',
     'test/spec/**/*.js',
     '!test/spec/loaders/**/*.js'
-  ], ['quality', 'webpack', 'devpack', 'test']);
+  ], ['lint', 'webpack', 'devpack', 'test']);
   gulp.watch([
     'loaders/**/*.js',
     'test/spec/loaders/**/*.js'
-  ], ['quality', 'mocha']);
+  ], ['lint', 'mocha']);
   gulp.watch(['integrationExamples/gpt/*.html'], ['test']);
   connect.server({
     https: argv.https,
@@ -189,21 +195,11 @@ gulp.task('watch', function () {
   });
 });
 
-gulp.task('quality', ['hint', 'jscs']);
-
-gulp.task('hint', function () {
-  return gulp.src('src/**/*.js')
-    .pipe(jshint('.jshintrc'))
-    .pipe(jshint.reporter('jshint-stylish'))
-    .pipe(jshint.reporter('fail'));
-});
-
-gulp.task('jscs', function () {
-  return gulp.src('src/**/*.js')
-    .pipe(jscs({
-      configPath: '.jscsrc'
-    }))
-    .pipe(jscs.reporter());
+gulp.task('lint', () => {
+  return gulp.src(['src/**/*.js', 'test/**/*.js'])
+    .pipe(eslint())
+    .pipe(eslint.format('stylish'))
+    .pipe(eslint.failAfterError());
 });
 
 gulp.task('clean-docs', function () {

package.json

@@ -31,17 +31,21 @@
     "del": "^2.2.0",
     "ejs": "^2.5.1",
     "es5-shim": "^4.5.2",
+    "eslint-config-standard": "^10.2.0",
+    "eslint-plugin-import": "^2.2.0",
+    "eslint-plugin-node": "^4.2.2",
+    "eslint-plugin-promise": "^3.5.0",
+    "eslint-plugin-standard": "^3.0.1",
     "faker": "^3.1.0",
     "fs.extra": "^1.3.2",
     "gulp": "^3.8.7",
     "gulp-babel": "^6.1.2",
-    "gulp-clean": "^0.3.1",
+    "gulp-clean": "^0.3.2",
     "gulp-concat": "^2.6.0",
     "gulp-connect": "^2.0.6",
+    "gulp-eslint": "^3.0.1",
     "gulp-header": "^1.7.1",
-    "gulp-jscs": "^3.0.2",
     "gulp-jsdoc-to-markdown": "^1.2.1",
-    "gulp-jshint": "^1.8.4",
     "gulp-karma": "0.0.4",
     "gulp-mocha": "^2.2.0",
     "gulp-optimize-js": "^1.1.0",
@@ -54,7 +58,6 @@
     "gulp-zip": "^3.1.0",
     "istanbul": "^0.3.2",
     "istanbul-instrumenter-loader": "^0.1.2",
-    "jshint-stylish": "^2.2.1",
     "json-loader": "^0.5.1",
     "karma": "^0.13.2",
     "karma-babel-preprocessor": "^6.0.1",

src/adaptermanager.js

@@ -11,7 +11,7 @@ import { BaseAdapter } from './adapters/baseAdapter';
 var _bidderRegistry = {};
 exports.bidderRegistry = _bidderRegistry;
 
-//create s2s settings objectType_function
+// create s2s settings objectType_function
 let _s2sConfig = {};
 var _analyticsRegistry = {};
 let _bidderSequence = null;
@@ -31,7 +31,7 @@ function getBids({bidderCode, requestId, bidderRequestId, adUnits}) {
         return Object.assign({}, bid, {
           placementCode: adUnit.code,
           mediaType: adUnit.mediaType,
-          transactionId : adUnit.transactionId,
+          transactionId: adUnit.transactionId,
           sizes: sizes,
           bidId: bid.bid_id || utils.getUniqueIdentifierStr(),
           bidderRequestId,
@@ -57,17 +57,17 @@ exports.callBids = ({adUnits, cbTimeout}) => {
     bidderCodes = shuffle(bidderCodes);
   }
 
-  if(_s2sConfig.enabled) {
-    //these are called on the s2s adapter
+  if (_s2sConfig.enabled) {
+    // these are called on the s2s adapter
     let adaptersServerSide = _s2sConfig.bidders;
 
-    //don't call these client side
+    // don't call these client side
     bidderCodes = bidderCodes.filter((elm) => {
       return !adaptersServerSide.includes(elm);
     });
     let adUnitsCopy = utils.cloneJson(adUnits);
 
-    //filter out client side bids
+    // filter out client side bids
     adUnitsCopy.forEach((adUnit) => {
       if (adUnit.sizeMapping) {
         adUnit.sizes = mapSizes(adUnit);
@@ -90,17 +90,17 @@ exports.callBids = ({adUnits, cbTimeout}) => {
         requestId,
         bidderRequestId,
         tid,
-        bids: getBids({bidderCode, requestId, bidderRequestId, 'adUnits' : adUnitsCopy}),
+        bids: getBids({bidderCode, requestId, bidderRequestId, 'adUnits': adUnitsCopy}),
         start: new Date().getTime(),
         auctionStart: auctionStart,
         timeout: _s2sConfig.timeout
       };
-      //Pushing server side bidder
+      // Pushing server side bidder
       $$PREBID_GLOBAL$$._bidsRequested.push(bidderRequest);
     });
 
-    let s2sBidRequest = {tid, 'ad_units' : adUnitsCopy};
-    let s2sAdapter = _bidderRegistry[_s2sConfig.adapter]; //jshint ignore:line
+    let s2sBidRequest = {tid, 'ad_units': adUnitsCopy};
+    let s2sAdapter = _bidderRegistry[_s2sConfig.adapter]; // jshint ignore:line
     utils.logMessage(`CALLING S2S HEADER BIDDERS ==== ${adaptersServerSide.join(',')}`);
     s2sAdapter.setConfig(_s2sConfig);
     s2sAdapter.callBids(s2sBidRequest);
@@ -138,8 +138,8 @@ function transformHeightWidth(adUnit) {
   sizes.forEach(size => {
     let heightWidth = size.split('x');
     let sizeObj = {
-      'w' : parseInt(heightWidth[0]),
-      'h' : parseInt(heightWidth[1])
+      'w': parseInt(heightWidth[0]),
+      'h': parseInt(heightWidth[1])
     };
     sizesObj.push(sizeObj);
   });
@@ -148,14 +148,11 @@ function transformHeightWidth(adUnit) {
 
 exports.registerBidAdapter = function (bidAdaptor, bidderCode) {
   if (bidAdaptor && bidderCode) {
-
     if (typeof bidAdaptor.callBids === CONSTANTS.objectType_function) {
       _bidderRegistry[bidderCode] = bidAdaptor;
-
     } else {
       utils.logError('Bidder adaptor error for bidder code: ' + bidderCode + 'bidder must implement a callBids() function');
     }
-
   } else {
     utils.logError('bidAdaptor or bidderCode not specified');
   }
@@ -173,7 +170,7 @@ exports.aliasBidAdapter = function (bidderCode, alias) {
       try {
         let newAdapter = null;
         if (bidAdaptor instanceof BaseAdapter) {
-          //newAdapter = new bidAdaptor.constructor(alias);
+          // newAdapter = new bidAdaptor.constructor(alias);
           utils.logError(bidderCode + ' bidder does not currently support aliasing.', 'adaptermanager.aliasBidAdapter');
         } else {
           newAdapter = bidAdaptor.createNew();
@@ -191,7 +188,6 @@ exports.aliasBidAdapter = function (bidderCode, alias) {
 
 exports.registerAnalyticsAdapter = function ({adapter, code}) {
   if (adapter && code) {
-
     if (typeof adapter.enableAnalytics === CONSTANTS.objectType_function) {
       adapter.code = code;
       _analyticsRegistry[code] = adapter;