[eslint config] Update to eslint v2: Merge remote-tracking branch 'origin/harry-eslint-v2'

Closes airbnb#730.

Author: ljharb

README.md

@@ -346,6 +346,54 @@ Other Style Guides
     const nodes = Array.from(foo);
     ```
 
+  - [4.5](#4.5) <a name='4.5'></a> Use return statements in array method callbacks. It's ok to omit the return if the function body consists of a single statement following [8.2](#8.2). eslint: [`array-callback-return`](http://eslint.org/docs/rules/array-callback-return)
+
+    ```javascript
+    // good
+    [1, 2, 3].map((x) => {
+      const y = x + 1;
+      return x * y;
+    });
+
+    // good
+    [1, 2, 3].map(x => x + 1);
+
+    // bad
+    const flat = {};
+    [[0, 1], [2, 3], [4, 5]].reduce((memo, item, index) => {
+      const flatten = memo.concat(item);
+      flat[index] = memo.concat(item);
+    });
+
+    // good
+    const flat = {};
+    [[0, 1], [2, 3], [4, 5]].reduce((memo, item, index) => {
+      const flatten = memo.concat(item);
+      flat[index] = flatten;
+      return flatten;
+    });
+
+    // bad
+    inbox.filter((msg) => {
+      const { subject, author } = msg;
+      if (subject === 'Mockingbird') {
+        return author === 'Harper Lee';
+      } else {
+        return false;
+      }
+    });
+
+    // good
+    inbox.filter((msg) => {
+      const { subject, author } = msg;
+      if (subject === 'Mockingbird') {
+        return author === 'Harper Lee';
+      }
+
+      return false;
+    });
+    ```
+
 **[⬆ back to top](#table-of-contents)**
 
 ## Destructuring
@@ -447,7 +495,7 @@ Other Style Guides
     ```
 
   <a name="es6-template-literals"></a>
-  - [6.4](#6.4) <a name='6.4'></a> When programmatically building up strings, use template strings instead of concatenation. eslint: [`prefer-template`](http://eslint.org/docs/rules/prefer-template.html) jscs: [`requireTemplateStrings`](http://jscs.info/rule/requireTemplateStrings)
+  - [6.4](#6.4) <a name='6.4'></a> When programmatically building up strings, use template strings instead of concatenation. eslint: [`prefer-template`](http://eslint.org/docs/rules/prefer-template.html) [`template-curly-spacing`](http://eslint.org/docs/rules/template-curly-spacing) jscs: [`requireTemplateStrings`](http://jscs.info/rule/requireTemplateStrings)
 
     > Why? Template strings give you a readable, concise syntax with proper newlines and string interpolation features.
 
@@ -462,6 +510,11 @@ Other Style Guides
       return ['How are you, ', name, '?'].join();
     }
 
+    // bad
+    function sayHi(name) {
+      return `How are you, ${ name }?`;
+    }
+
     // good
     function sayHi(name) {
       return `How are you, ${name}?`;
@@ -535,7 +588,7 @@ Other Style Guides
     ```
 
   <a name="es6-rest"></a>
-  - [7.6](#7.6) <a name='7.6'></a> Never use `arguments`, opt to use rest syntax `...` instead.
+  - [7.6](#7.6) <a name='7.6'></a> Never use `arguments`, opt to use rest syntax `...` instead. [`prefer-rest-params`](http://eslint.org/docs/rules/prefer-rest-params)
 
     > Why? `...` is explicit about which arguments you want pulled. Plus rest arguments are a real Array and not Array-like like `arguments`.
 
@@ -771,6 +824,19 @@ Other Style Guides
     });
     ```
 
+  - [8.5](#8.5) <a name='8.5'></a> Avoid confusing arrow function syntax (`=>`) with comparison operators (`<=`, `>=`). eslint: [`no-confusing-arrow`](http://eslint.org/docs/rules/no-confusing-arrow)
+
+    ```js
+    // bad
+    const itemHeight = item => item.height > 256 ? item.largeSize : item.smallSize;
+
+    // bad
+    const itemHeight = (item) => item.height > 256 ? item.largeSize : item.smallSize;
+
+    // good
+    const itemHeight = item => { return item.height > 256 ? item.largeSize : item.smallSize; }
+    ```
+
 **[⬆ back to top](#table-of-contents)**
 
 
@@ -883,6 +949,34 @@ Other Style Guides
     }
     ```
 
+  - [9.5](#9.5) <a name='9.5'></a> Classes have a default constructor if one is not specified. An empty constructor function or one that just delegates to a parent class is unnecessary. [`no-useless-constructor`](http://eslint.org/docs/rules/no-useless-constructor)
+
+    ```javascript
+    // bad
+    class Jedi {
+      constructor() {}
+
+      getName() {
+        return this.name;
+      }
+    }
+
+    // bad
+    class Rey extends Jedi {
+      constructor(...args) {
+        super(args);
+      }
+    }
+
+    // good
+    class Rey extends Jedi {
+      constructor(...args) {
+        super(args);
+        this.name = 'Rey';
+      }
+    }
+    ```
+
 **[⬆ back to top](#table-of-contents)**
 
 
@@ -1592,8 +1686,8 @@ Other Style Guides
     })(this);↵
     ```
 
-  - [18.6](#18.6) <a name='18.6'></a> Use indentation when making long method chains. Use a leading dot, which
-    emphasizes that the line is a method call, not a new statement.
+  - [18.6](#18.6) <a name='18.6'></a> Use indentation when making long method chains (more than 2 method chains). Use a leading dot, which
+    emphasizes that the line is a method call, not a new statement. eslint: [`newline-per-chained-call`](http://eslint.org/docs/rules/newline-per-chained-call) [`no-whitespace-before-property`](http://eslint.org/docs/rules/no-whitespace-before-property)
 
     ```javascript
     // bad
@@ -1630,6 +1724,9 @@ Other Style Guides
       .append('svg:g')
         .attr('transform', 'translate(' + (radius + margin) + ',' + (radius + margin) + ')')
         .call(tron.led);
+
+    // good
+    const leds = stage.selectAll('.led').data(data);
     ```
 
   - [18.7](#18.7) <a name='18.7'></a> Leave a blank line after blocks and before the next statement. jscs: [`requirePaddingNewLinesAfterBlocks`](http://jscs.info/rule/requirePaddingNewLinesAfterBlocks)

packages/eslint-config-airbnb/CHANGELOG.md

@@ -1,3 +1,21 @@
+6.0.0 / 2016-02-21
+==================
+- [breaking] enable `array-callback-return`
+- [breaking] enable `no-confusing-arrow`
+- [breaking] enable `no-new-symbol`
+- [breaking] enable `no-restricted-imports`
+- [breaking] enable `no-useless-constructor`
+- [breaking] enable `prefer-rest-params`
+- [breaking] enable `template-curly-spaces`
+- [breaking] enable `newline-per-chained-call`
+- [breaking] enable `one-var-declaration-per-line`
+- [breaking] enable `no-self-assign`
+- [breaking] enable `no-whitespace-before-property`
+- [breaking] [react] enable `react/jsx-space-before-closing`
+- [breaking] [react] enable `static-methods` at top of `react/sort-comp`
+- [breaking] [react] don't `ignoreTranspilerName` for `react/display-name`
+- [peer+dev deps] update `eslint`, `eslint-plugin-react`
+
 5.0.1 / 2016-02-13
 ==================
  - [fix] `eslint` peerDep should not include breaking changes

packages/eslint-config-airbnb/package.json

@@ -43,14 +43,14 @@
   "homepage": "https://github.com/airbnb/javascript",
   "devDependencies": {
     "babel-tape-runner": "1.2.0",
-    "eslint": "^1.10.3",
-    "eslint-plugin-react": "^3.16.1",
+    "eslint": "^2.2.0",
+    "eslint-plugin-react": "^4.0.0",
     "react": "^0.14.7",
     "tape": "^4.4.0",
     "parallelshell": "^2.0.0"
   },
   "peerDependencies": {
-    "eslint": "^1.0.0",
-    "eslint-plugin-react": "^3.16.1"
+    "eslint": "^2.2.0",
+    "eslint-plugin-react": "^4.0.0"
   }
 }

packages/eslint-config-airbnb/rules/best-practices.js

@@ -2,6 +2,9 @@ module.exports = {
   'rules': {
     // enforces getter/setter pairs in objects
     'accessor-pairs': 0,
+    // enforces return statements in callbacks of array's methods
+    // http://eslint.org/docs/rules/array-callback-return
+    'array-callback-return': 2,
     // treat var statements as if they were block scoped
     'block-scoped-var': 2,
     // specify the maximum cyclomatic complexity allowed in a program
@@ -20,6 +23,9 @@ module.exports = {
     'eqeqeq': 2,
     // make sure for-in loops have an if statement
     'guard-for-in': 2,
+    // Blacklist certain identifiers to prevent them being used
+    // http://eslint.org/docs/rules/id-blacklist
+    'id-blacklist': 0,
     // disallow the use of alert, confirm, and prompt
     'no-alert': 1,
     // disallow use of arguments.caller or arguments.callee
@@ -31,8 +37,9 @@ module.exports = {
     'no-div-regex': 0,
     // disallow else after a return in an if
     'no-else-return': 2,
-    // disallow use of labels for anything other then loops and switches
-    'no-empty-label': 2,
+    // disallow Unnecessary Labels
+    // http://eslint.org/docs/rules/no-extra-label
+    'no-extra-label': 2,
     // disallow comparisons to null without a type-checking operator
     'no-eq-null': 0,
     // disallow use of eval()
@@ -53,8 +60,8 @@ module.exports = {
     'no-invalid-this': 0,
     // disallow usage of __iterator__ property
     'no-iterator': 2,
-    // disallow use of labeled statements
-    'no-labels': 2,
+    // disallow use of labels for anything other then loops and switches
+    'no-labels': [2, { 'allowLoop': false, 'allowSwitch': false }],
     // disallow unnecessary nested blocks
     'no-lone-blocks': 2,
     // disallow creation of functions within loops
@@ -96,8 +103,14 @@ module.exports = {
     'no-sequences': 2,
     // restrict what can be thrown as an exception
     'no-throw-literal': 2,
+    // disallow unmodified conditions of loops
+    // http://eslint.org/docs/rules/no-unmodified-loop-condition
+    'no-unmodified-loop-condition': 0,
     // disallow usage of expressions in statement position
     'no-unused-expressions': 2,
+    // disallow unused labels
+    // http://eslint.org/docs/rules/no-unused-labels
+    'no-unused-labels': 2,
     // disallow unnecessary .call() and .apply()
     'no-useless-call': 0,
     // disallow use of void operator

packages/eslint-config-airbnb/rules/es6.js

@@ -1,25 +1,15 @@
 module.exports = {
   'env': {
-    'es6': false
+    'es6': true
   },
-  'ecmaFeatures': {
-    'arrowFunctions': true,
-    'blockBindings': true,
-    'classes': true,
-    'defaultParams': true,
-    'destructuring': true,
-    'forOf': true,
-    'generators': false,
-    'modules': true,
-    'objectLiteralComputedProperties': true,
-    'objectLiteralDuplicateProperties': false,
-    'objectLiteralShorthandMethods': true,
-    'objectLiteralShorthandProperties': true,
-    'restParams': true,
-    'spread': true,
-    'superInFunctions': true,
-    'templateStrings': true,
-    'jsx': true
+  'parserOptions': {
+    'ecmaVersion': 6,
+    'sourceType': 'module',
+    'ecmaFeatures': {
+      'jsx': true,
+      'generators': false,
+      'objectLiteralDuplicateProperties': false
+    }
   },
   'rules': {
     // enforces no braces where they can be omitted
@@ -38,12 +28,24 @@ module.exports = {
     'generator-star-spacing': 0,
     // disallow modifying variables of class declarations
     'no-class-assign': 0,
+    // disallow arrow functions where they could be confused with comparisons
+    // http://eslint.org/docs/rules/no-confusing-arrow
+    'no-confusing-arrow': 2,
     // disallow modifying variables that are declared using const
     'no-const-assign': 2,
+    // disallow symbol constructor
+    // http://eslint.org/docs/rules/no-new-symbol
+    'no-new-symbol': 2,
+    // disallow specific imports
+    // http://eslint.org/docs/rules/no-restricted-imports
+    'no-restricted-imports': 0,
     // disallow to use this/super before super() calling in constructors.
     'no-this-before-super': 0,
     // require let or const instead of var
     'no-var': 2,
+    // disallow unnecessary constructor
+    // http://eslint.org/docs/rules/no-useless-constructor
+    'no-useless-constructor': 2,
     // require method and property shorthand syntax for object literals
     // https://github.com/eslint/eslint/blob/master/docs/rules/object-shorthand.md
     'object-shorthand': [2, 'always'],
@@ -55,10 +57,22 @@ module.exports = {
     'prefer-spread': 0,
     // suggest using Reflect methods where applicable
     'prefer-reflect': 0,
+    // use rest parameters instead of arguments
+    // http://eslint.org/docs/rules/prefer-rest-params
+    'prefer-rest-params': 2,
     // suggest using template literals instead of string concatenation
     // http://eslint.org/docs/rules/prefer-template
     'prefer-template': 2,
     // disallow generator functions that do not have yield
-    'require-yield': 0
+    'require-yield': 0,
+    // import sorting
+    // http://eslint.org/docs/rules/sort-imports
+    'sort-imports': 0,
+    // enforce usage of spacing in template strings
+    // http://eslint.org/docs/rules/template-curly-spacing
+    'template-curly-spacing': 2,
+    // enforce spacing around the * in yield* expressions
+    // http://eslint.org/docs/rules/yield-star-spacing
+    'yield-star-spacing': [2, 'after']
   }
 };

packages/eslint-config-airbnb/rules/react.js

@@ -10,7 +10,7 @@ module.exports = {
   'rules': {
     // Prevent missing displayName in a React component definition
     // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/display-name.md
-    'react/display-name': [0, { 'acceptTranspilerName': false }],
+    'react/display-name': [0, { 'ignoreTranspilerName': false }],
     // Forbid certain propTypes (any, array, object)
     // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/forbid-prop-types.md
     'react/forbid-prop-types': [0, { 'forbid': ['any', 'array', 'object'] }],
@@ -54,8 +54,8 @@ module.exports = {
     // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-pascal-case.md
     'react/jsx-pascal-case': 0,
     // Enforce propTypes declarations alphabetical sorting
-    // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-sort-prop-types.md
-    'react/jsx-sort-prop-types': [0, {
+    // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/sort-prop-types.md
+    'react/sort-prop-types': [0, {
       'ignoreCase': false,
       'callbacksLast': false,
     }],
@@ -116,10 +116,14 @@ module.exports = {
     // Prevent extra closing tags for components without children
     // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/self-closing-comp.md
     'react/self-closing-comp': 2,
+    // Enforce spaces before the closing bracket of self-closing JSX elements
+    // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-space-before-closing.md
+    'react/jsx-space-before-closing': [2, 'always'],
     // Enforce component methods order
     // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/sort-comp.md
     'react/sort-comp': [2, {
       'order': [
+        'static-methods',
         'lifecycle',
         '/^on.+$/',
         '/^(get|set)(?!(InitialState$|DefaultProps$|ChildContext$)).+$/',