module.exports = {
    /**
 * ref.:
 *   + http://eslint.org/docs/rules/[rule-name]
 *   + https://pirosikick.github.io/eslintrc-editor/
 *
 * eslint v2.x
 */
  "root": true,
  "extends": "eslint:recommended", // @see http://eslint.org/docs/rules/

  "env": {                         // @see http://eslint.org/docs/user-guide/configuring
    "browser": true,
    "node": true,
    "es6": true,
    "mocha": true,
    "commonjs": true
  },

  "parser": "babel-eslint",

  "parserOptions": {
    "ecmaVersion": 6,
    "sourceType": "module"
  },

  "rules": {
    /* switch off built-in(eslint:recommended) */
    "no-fallthrough": 'off',
    "no-cond-assign": 'warn', // disallow assignment in conditional expressions
    "no-extra-boolean-cast": 'warn', // disallow double-negation boolean casts in a boolean context
    /* Best Practices */
    "accessor-pairs": ['error', {"getWithoutSet": false}], // Enforces getter/setter pairs in objects
    "array-callback-return": 'error', // Enforces return statements in callbacks of array's methods
    "block-scoped-var": 'error', // treat var statements as if they were block scoped
    "curly": ['off'], // specify curly brace conventions for all control statements
    "default-case": 'error', // require default case in switch statements
    "dot-location": ['error', "property"], // enforces consistent newlines before or after dots
    "dot-notation": 'error', // encourages use of dot notation whenever possible, foo.bar instead of foo['bar']
    "eqeqeq": 'error', // require the use of === and !==
    "no-alert": 'error', // disallow the use of alert, confirm, and prompt
    "no-caller": 'error', // disallow use of arguments.caller or arguments.callee
    "no-console": 0,
    "no-div-regex": 'error', // disallow division operators explicitly at beginning of regular expression
    "no-eq-null": 'error', // disallow comparisons to null without a type-checking operator,foo === null instead of foo == null
    "no-eval": 'error', // disallow use of eval()
    "no-extend-native": 'error', // disallow adding to native types
    "no-extra-bind": 'error', // disallow unnecessary function binding
    "no-extra-label": 'error', // disallow unnecessary labels
    "no-invalid-this": 'error', // disallow this keywords outside of classes or class-like objects
    "no-iterator": 'error', // disallow the use of the __iterator__ property
    "no-labels": 'error', // disallow use of labeled statements
    "no-lone-blocks": 'error', // disallow unnecessary nested blocks
    "no-loop-func": 'error', // disallow creation of functions within loops
    "no-multi-str": 'error', // disallow use of multiline strings
    "no-new": 'error', // Disallow new For Side Effects
    "no-new-func": 'error', // disallow new operators with the Function object
    "no-new-wrappers": 'error', // disallow new operators with the String, Number, and Boolean objects
    "no-proto": 'error', // disallow the use of the __proto__ property
    "no-with": 'error', // disallow with statements
    "arrow-body-style": ['error', "as-needed"], // require braces in arrow function body
    "no-confusing-arrow": 'error', // disallow arrow functions where they could be confused with comparisons
    "object-shorthand": 'error', // require method and property shorthand syntax for object literals，{x} instead of {x: x}
    "prefer-arrow-callback": 'error', // suggest using arrow functions as callbacks
    "prefer-const": 'error', // require const declarations for variables that are never reassigned after declared
    "prefer-spread": 'error', // require spread operators instead of .apply() . foo(...args)
    "prefer-template": 'error', // require template literals instead of string concatenation
    "brace-style": ['error', "1tbs"], // enforce consistent brace style for blocks
    "camelcase": ['error', {"properties": "always"}], // enforce camelcase naming convention
    "no-array-constructor": 'error', // disallow Array constructors
    "no-multiple-empty-lines": ['error'], // disallow multiple empty lines
    "no-new-object": 'error', // disallow Object constructors
    /* can be fixed*/
    "keyword-spacing": 'error', // enforce consistent spacing before and after keywords
    "indent": ['error', 4, {"SwitchCase": 1}], // enforce consistent indentation(4 space)
    "no-trailing-spaces": 'error', // disallow trailing whitespace at the end of lines
    "func-call-spacing": 'error', // disallow spacing between function identifiers and their invocations
    "semi": 'error', // disallow semicolons instead of ASI
    "no-multi-spaces": ['error'], // disallow multiple spaces
    "comma-spacing": ['error', {'before': false, 'after': true}], // enforce consistent spacing before and after commas
    "arrow-spacing": ['error', {'before': true, 'after': true}], // enforce consistent spacing before and after the arrow in arrow functions
    "space-infix-ops": "error", // require spacing around infix operators
    "no-var": "error",
    "quotes": ["error", "single"]
  }
}