Build: Switch from JSHint/JSCS to ESLint

Fixes #236
Closes #238

Author: mgol

.eslintignore

@@ -0,0 +1,8 @@
+coverage
+external
+node_modules
+*.min.js
+src/intro.js
+src/outro.js
+test/data/jquery-*.js
+test/data/jquery.mobile-*.js

.eslintrc.json

@@ -0,0 +1,8 @@
+{
+	"extends": "jquery",
+	"root": true,
+	"env": {
+		"browser": false,
+		"node": true
+	}
+}

.gitignore

@@ -1,4 +1,3 @@
-dist
 coverage
 CDN
 .project
@@ -8,4 +7,9 @@ CDN
 *.patch
 /*.html
 .DS_Store
-node_modules
+
+# Ignore everything in dist folder except for eslint config
+/dist/*
+!/dist/.eslintrc.json
+
+node_modules

.jscsrc

@@ -3,17 +3,6 @@ module.exports = function( grunt ) {
 
 	"use strict";
 
-	// The concatenated file won't pass onevar but our modules can
-	var readOptionalJSON = function( filepath ) {
-			var data = {};
-			try {
-				data = grunt.file.readJSON( filepath );
-			} catch ( e ) {}
-			return data;
-		},
-		srcHintOptions = readOptionalJSON( "src/.jshintrc" );
-	delete srcHintOptions.onevar;
-
 	// Project configuration.
 	grunt.initConfig( {
 		pkg: grunt.file.readJSON( "package.json" ),
@@ -77,13 +66,24 @@ module.exports = function( grunt ) {
 				force: true
 			}
 		},
-		jscs: {
-			src: [
-				"test/*.js",
-				"<%= files %>",
-				"Gruntfile.js",
-				"build/**/*.js"
-			]
+		eslint: {
+			options: {
+
+				// See https://github.com/sindresorhus/grunt-eslint/issues/119
+				quiet: true
+			},
+
+			dist: {
+				src: "dist/jquery-migrate.js"
+			},
+			dev: {
+				src: [
+					"Gruntfile.js",
+					"build/**/*.js",
+					"src/**/*.js",
+					"test/**/*.js"
+				]
+			}
 		},
 		npmcopy: {
 			all: {
@@ -97,24 +97,6 @@ module.exports = function( grunt ) {
 					"qunit/LICENSE.txt": "qunitjs/LICENSE.txt" }
 			}
 		},
-		jshint: {
-			dist: {
-				src: [ "dist/jquery-migrate.js" ],
-				options: srcHintOptions
-			},
-			tests: {
-				src: [ "test/*.js" ],
-				options: {
-					jshintrc: "test/.jshintrc"
-				}
-			},
-			grunt: {
-				src: [ "Gruntfile.js" ],
-				options: {
-					jshintrc: ".jshintrc"
-				}
-			}
-		},
 		uglify: {
 			all: {
 				files: {
@@ -144,7 +126,15 @@ module.exports = function( grunt ) {
 	// Just an alias
 	grunt.registerTask( "test", [ "qunit" ] );
 
-	grunt.registerTask( "lint", [ "jshint", "jscs" ] );
+	grunt.registerTask( "lint", [
+
+		// Running the full eslint task without breaking it down to targets
+		// would run the dist target first which would point to errors in the built
+		// file, making it harder to fix them. We want to check the built file only
+		// if we already know the source files pass the linter.
+		"eslint:dev",
+		"eslint:dist"
+	] );
 	grunt.registerTask( "build", [ "concat", "uglify", "lint" ] );
 
 	grunt.registerTask( "default", [ "build", "test" ] );

.jshintrc

@@ -24,7 +24,7 @@ var releaseVersion,
 	// Windows needs the .cmd version but will find the non-.cmd
 	// On Windows, also ensure the HOME environment variable is set
 	gruntCmd = process.platform === "win32" ? "grunt.cmd" : "grunt",
-	npmCmd = process.platform == "win32" ? "npm.cmd" : "npm",
+	npmCmd = process.platform === "win32" ? "npm.cmd" : "npm",
 
 	readmeFile = "README.md",
 	packageFile = "package.json",
@@ -120,7 +120,7 @@ function initialize( next ) {
 // (look for " BRANCH     pushes to BRANCH     (up to date)")
 
 function checkGitStatus( next ) {
-	child.execFile( "git", [ "status" ], function( error, stdout, stderr ) {
+	child.execFile( "git", [ "status" ], function( error, stdout ) {
 		var onBranch = ( ( stdout || "" ).match( /On branch (\S+)/ ) || [] )[ 1 ];
 		if ( onBranch !== branch ) {
 			die( "Branches don't match: Wanted " + branch + ", got " + onBranch );
@@ -151,7 +151,7 @@ function updateVersions( next ) {
 }
 
 function gruntBuild( next ) {
-	exec( gruntCmd, [], function( error, stdout ) {
+	exec( gruntCmd, [], function( error, stdout, stderr ) {
 		if ( error ) {
 			die( error + stderr );
 		}
@@ -234,7 +234,7 @@ function updateSourceVersion( ver ) {
 	}
 }
 
-function updateReadmeVersion( ver ) {
+function updateReadmeVersion() {
 	var readme = fs.readFileSync( readmeFile, "utf8" );
 
 	// Change version references from the old version to the new one.
@@ -243,8 +243,10 @@ function updateReadmeVersion( ver ) {
 		status( "Skipping " + readmeFile + " update (beta release)" );
 	} else {
 		status( "Updating " + readmeFile );
-		readme = readme
-			.replace( /jquery-migrate-\d+\.\d+\.\d+(?:-\w+)?/g, "jquery-migrate-" + releaseVersion );
+		readme = readme.replace(
+			/jquery-migrate-\d+\.\d+\.\d+(?:-\w+)?/g,
+			"jquery-migrate-" + releaseVersion
+		);
 		if ( !dryrun ) {
 			fs.writeFileSync( readmeFile, readme );
 		}

Gruntfile.js

@@ -0,0 +1,8 @@
+{
+	"extends": "../src/.eslintrc.json",
+	"root": true,
+	"rules": {
+		// That is okay for the built version
+		"no-multiple-empty-lines": "off"
+	}
+}

build/release.js

@@ -28,15 +28,15 @@
   "devDependencies": {
     "chalk": "1.1.3",
     "commitplease": "2.7.5",
+    "eslint-config-jquery": "1.0.0",
     "grunt": "0.4.5",
     "grunt-cli": "0.1.13",
     "grunt-contrib-concat": "1.0.1",
-    "grunt-contrib-jshint": "1.0.0",
     "grunt-contrib-uglify": "2.0.0",
     "grunt-contrib-watch": "1.0.0",
     "grunt-coveralls": "1.0.1",
+    "grunt-eslint": "19.0.0",
     "grunt-git-authors": "3.2.0",
-    "grunt-jscs": "2.8.0",
     "grunt-npmcopy": "0.1.0",
     "grunt-qunit-istanbul": "0.6.0",
     "jquery": "3.1.1",

dist/.eslintrc.json

@@ -0,0 +1,25 @@
+{
+	"env": {
+		"browser": false,
+		"node": false
+	},
+	// Support: IE <=9 only, Android <=4.0 only
+	// The above browsers are failing a lot of tests in the ES5
+	// test suite at http://test262.ecmascript.org.
+	"parserOptions": {
+		"ecmaVersion": 3
+	},
+	"globals": {
+		"window": true,
+
+		"define": true,
+		"module": true,
+
+		"jQuery": true,
+		"migrateWarn": true,
+		"migrateWarnFunc": true,
+		"migrateWarnProp": true,
+
+		"noGlobal": true
+	}
+}

package.json

@@ -29,7 +29,7 @@ jQuery.find = function( selector ) {
 		// The nonstandard and undocumented unquoted-hash was removed in jQuery 1.12.0
 		// First see if qS thinks it's a valid selector, if so avoid a false positive
 		try {
-			document.querySelector( selector );
+			window.document.querySelector( selector );
 		} catch ( err1 ) {
 
 			// Didn't *look* valid to qSA, warn and try quoting what we think is the value
@@ -40,7 +40,7 @@ jQuery.find = function( selector ) {
 			// If the regexp *may* have created an invalid selector, don't update it
 			// Note that there may be false alarms if selector uses jQuery extensions
 			try {
-				document.querySelector( selector );
+				window.document.querySelector( selector );
 				migrateWarn( "Attribute selector with '#' must be quoted: " + args[ 0 ] );
 				args[ 0 ] = selector;
 			} catch ( err2 ) {

src/.eslintrc.json

@@ -25,7 +25,7 @@ jQuery.event.fix = function( originalEvent ) {
 		migrateWarn( "jQuery.event.fixHooks are deprecated and removed: " + type );
 		if ( ( props = fixHook.props ) && props.length ) {
 			while ( props.length ) {
-			   jQuery.event.addProp( props.pop() );
+				jQuery.event.addProp( props.pop() );
 			}
 		}
 	}
@@ -67,12 +67,12 @@ jQuery.each( [ "load", "unload", "error" ], function( _, name ) {
 
 // Trigger "ready" event only once, on document ready
 jQuery( function() {
-	jQuery( document ).triggerHandler( "ready" );
+	jQuery( window.document ).triggerHandler( "ready" );
 } );
 
 jQuery.event.special.ready = {
 	setup: function() {
-		if ( this === document ) {
+		if ( this === window.document ) {
 			migrateWarn( "'ready' event is deprecated" );
 		}
 	}

src/.jshintrc

@@ -1,14 +1,17 @@
-;(function( factory ) {
-	/* jshint browserify:true */
+;( function( factory ) {
 	if ( typeof define === "function" && define.amd ) {
+
 		// AMD. Register as an anonymous module.
 		define( [ "jquery" ], window, factory );
 	} else if ( typeof module === "object" && module.exports ) {
+
 		// Node/CommonJS
+		// eslint-disable-next-line no-undef
 		module.exports = factory( require( "jquery" ), window );
 	} else {
+
 		// Browser globals
 		factory( jQuery, window );
 	}
-}(function( jQuery, window ) {
+} )( function( jQuery, window ) {
 "use strict";

src/core.js

@@ -1,11 +1,14 @@
+/* exported migrateWarn, migrateWarnFunc, migrateWarnProp */
 
 ( function() {
 
 	// Support: IE9 only
 	// IE9 only creates console object when dev tools are first opened
 	// Also, avoid Function#bind here to simplify PhantomJS usage
 	var log = window.console && window.console.log &&
-			function() { window.console.log.apply( window.console, arguments ); },
+		function() {
+			window.console.log.apply( window.console, arguments );
+		},
 		rbadVersions = /^[12]\./;
 
 	if ( !log ) {
@@ -79,7 +82,7 @@ function migrateWarnFunc( obj, prop, newFunc, msg ) {
 	};
 }
 
-if ( document.compatMode === "BackCompat" ) {
+if ( window.document.compatMode === "BackCompat" ) {
 
 	// JQuery has never supported or tested Quirks Mode
 	migrateWarn( "jQuery is not compatible with Quirks Mode" );

src/event.js

@@ -11,7 +11,7 @@ jQuery.fn.offset = function() {
 		return origin;
 	}
 
-	docElem = ( elem.ownerDocument || document ).documentElement;
+	docElem = ( elem.ownerDocument || window.document ).documentElement;
 	if ( !jQuery.contains( docElem, elem ) ) {
 		migrateWarn( "jQuery.fn.offset() requires an element connected to a document" );
 		return origin;

src/intro.js

@@ -1,2 +1,2 @@
 return jQuery;
-}));
+} );