Build: ESLint setup improvements

1. Use the short name of the preset in the config.
2. Run ESLint first on non-minified files.
3. Explicitly specify environments in every config file (those settings cascade
which means we've been assuming a Node.js environment where we shouldn't have).

.eslintrc-browser.json

@@ -0,0 +1,31 @@
+{
+	"root": true,
+
+	"extends": "jquery",
+
+	// 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
+	},
+
+	// The browser env is not enabled on purpose so that code takes
+	// all browser-only globals from window instead of assuming
+	// they're available as globals. This makes it possible to use
+	// jQuery with tools like jsdom which provide a custom window
+	// implementation.
+	"env": {},
+
+	"globals": {
+		"window": true,
+		"jQuery": true,
+		"define": true,
+		"module": true,
+		"noGlobal": true
+	},
+
+	"rules": {
+		"strict": ["error", "function"]
+	}
+}

.eslintrc-node.json

@@ -0,0 +1,13 @@
+{
+	"root": true,
+
+	"extends": "jquery",
+
+	"parserOptions": {
+		"ecmaVersion": 5
+	},
+
+	"env": {
+		"node": true
+	}
+}

.eslintrc.json

@@ -1,7 +1,5 @@
 {
-	"extends": "eslint-config-jquery",
 	"root": true,
-	"env": {
-		"node": true
-	}
+
+	"extends": "./.eslintrc-node.json"
 }

Gruntfile.js

@@ -203,12 +203,21 @@ module.exports = function( grunt ) {
 
 	grunt.registerTask( "lint", [
 		"jsonlint",
-		runIfNewNode( "eslint" )
+
+		// 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.
+		runIfNewNode( "eslint:dev" ),
+		runIfNewNode( "eslint:dist" )
 	] );
 
 	grunt.registerTask( "lint:newer", [
 		"newer:jsonlint",
-		runIfNewNode( "newer:eslint" )
+
+		// Don't replace it with just the task; see the above comment.
+		runIfNewNode( "newer:eslint:dev" ),
+		runIfNewNode( "newer:eslint:dist" )
 	] );
 
 	grunt.registerTask( "test:fast", runIfNewNode( "node_smoke_tests" ) );

dist/.eslintrc.json

@@ -1,5 +1,8 @@
 {
-	"extends": "../src/.eslintrc.json",
+	"root": true,
+
+	"extends": "../.eslintrc-browser.json",
+
 	"rules": {
 		// That is okay for the built version
 		"no-multiple-empty-lines": "off",

src/.eslintrc.json

@@ -1,18 +1,5 @@
 {
-	// 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,
-		"jQuery": true,
-		"define": true,
-		"module": true,
-		"noGlobal": true
-	},
-	"rules": {
-		"strict": ["error", "function"]
-	}
+	"root": true,
+
+	"extends": "../.eslintrc-browser.json"
 }

test/.eslintrc.json

@@ -1,13 +1,15 @@
 {
+	"root": true,
+
+	"extends": "../.eslintrc-browser.json",
+
 	"env": {
+
+		// In source the browser env is not enabled but unit tests rely on them
+		// too much and we don't run them in non-browser environments anyway.
 		"browser": true
 	},
-	// 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": {
 		"require": false,
 		"define": false,
@@ -41,17 +43,19 @@
 		"baseURL": true,
 		"externalHost": true
 	},
+
 	"rules": {
 		// See https://github.com/eslint/eslint/issues/2342
 		"no-unused-vars": "off",
 
-		// Too much errors
+		// Too many errors
 		"max-len": "off",
 		"brace-style": "off",
 		"key-spacing": "off",
 		"camelcase": "off",
+		"strict": "off",
 
-		// Not really too much - waiting autofix features for these rules
+		// Not really too many - waiting for autofix features for these rules
 		"lines-around-comment": "off",
 		"dot-notation": "off"
 	}

test/node_smoke_tests/.eslintrc.json

@@ -1,7 +1,13 @@
 {
+	"root": true,
+
+	"extends": "../../.eslintrc-node.json",
+
+	"parserOptions": {
+		"ecmaVersion": 2015
+	},
+
 	"env": {
 		"es6": true
-	},
-	"extends" : "../../.eslintrc.json",
-	"root": true
+	}
 }

test/promises_aplus_adapters/.eslintrc.json

@@ -1,4 +1,5 @@
 {
-	"extends": "../../.eslintrc.json",
-	"root": true
+	"root": true,
+
+	"extends": "../../.eslintrc-node.json"
 }