.eslintrc

{
  "extends": "eslint:recommended",
  "env": {
    "node": true,
    "es6": true
  },

  "parser": "espree",
  "ecmaFeatures": {},

  //
  // http://eslint.org/docs/rules/
  //

  "rules": {
    //
    //
    // Rules
    //
    //
    // Rules in ESLint are divided into several categories to help you better understand their value. All rules are
    // disabled by default. ESLint recommends some rules to catch common problems, and you can use these recommended
    // rules by including `extends: "eslint:recommended"` in your configuration file. The rules that will be enabled
    // when you inherit from `eslint:recommended` are indicated below as "(recommended)". For more information on how to
    // configure rules and use `extends`, please see the [configuration documentation](../user-guide/configuring.md).
    //
    // Some rules are fixable using the `--fix` command line flag. Those rules are marked as "(fixable)" below.
    // Currently these fixes are mostly limited only to whitespace fixes.
    //

    //
    // Possible Errors
    //
    // The following rules point out areas where you might have made mistakes.
    //

    "comma-dangle": ["error", "always-multiline"], // disallow or enforce trailing commas (recommended)
    "no-cond-assign": "error", // disallow assignment in conditional expressions (recommended)
    "no-console": "error", // disallow use of `console` (recommended)
    "no-constant-condition": "error", // disallow use of constant expressions in conditions (recommended)
    "no-control-regex": "error", // disallow control characters in regular expressions (recommended)
    "no-debugger": "error", // disallow use of `debugger` (recommended)
    "no-dupe-args": "error", // disallow duplicate arguments in functions (recommended)
    "no-dupe-keys": "error", // disallow duplicate keys when creating object literals (recommended)
    "no-duplicate-case": "error", // disallow a duplicate case label. (recommended)
    "no-empty": "error", // disallow empty block statements (recommended)
    "no-empty-character-class": "error", // disallow the use of empty character classes in regular expressions (recommended)
    "no-ex-assign": "error", // disallow assigning to the exception in a `catch` block (recommended)
    "no-extra-boolean-cast": "error", // disallow double-negation boolean casts in a boolean context (recommended)
    "no-extra-parens": "off", // disallow unnecessary parentheses
    "no-extra-semi": "error", // disallow unnecessary semicolons (recommended) (fixable)
    "no-func-assign": "error", // disallow overwriting functions written as function declarations (recommended)
    "no-inner-declarations": "error", // disallow function or variable declarations in nested blocks (recommended)
    "no-invalid-regexp": "error", // disallow invalid regular expression strings in the `RegExp` constructor (recommended)
    "no-irregular-whitespace": "error", // disallow irregular whitespace outside of strings and comments (recommended)
    "no-negated-in-lhs": "error", // disallow negation of the left operand of an `in` expression (recommended)
    "no-obj-calls": "error", // disallow the use of object properties of the global object (`Math` and `JSON`) as functions (recommended)
    "no-regex-spaces": "error", // disallow multiple spaces in a regular expression literal (recommended)
    "no-sparse-arrays": "error", // disallow sparse arrays (recommended)
    "no-unexpected-multiline": "error", // disallow code that looks like two expressions but is actually one (recommended)
    "no-unreachable": "error", // disallow unreachable statements after a return, throw, continue, or break statement (recommended)
    "use-isnan": "error", // disallow comparisons with the value `NaN` (recommended)
    "valid-jsdoc": ["error", {"requireReturn": false}], // ensure JSDoc comments are valid
    "valid-typeof": "error", // ensure results of typeof are compared against a valid string (recommended)

    //
    // Best Practices
    //
    // These are rules designed to prevent you from making mistakes. They either prescribe a better way of doing
    // something or help you avoid footguns.
    //

    "accessor-pairs": "off", // enforce getter/setter pairs in objects
    "array-callback-return": "off", // enforce return statements in callbacks of array's methods
    "block-scoped-var": "off", // treat `var` statements as if they were block scoped
    "complexity": ["off", 11], // specify the maximum cyclomatic complexity allowed in a program
    "consistent-return": "off", // require `return` statements to either always or never specify values
    "curly": "off", // specify curly brace conventions for all control statements
    "default-case": "off", // require `default` case in `switch` statements
    "dot-location": "off", // enforce consistent newlines before or after dots
    "dot-notation": "off", // encourage use of dot notation whenever possible
    "eqeqeq": "off", // require use of `===` and `!==`
    "guard-for-in": "off", // ensure `for-in` loops have an `if` statement
    "no-alert": "off", // disallow use of `alert`, `confirm`, and `prompt`
    "no-caller": "off", // disallow use of `arguments.caller` or `arguments.callee`
    "no-case-declarations": "error", // disallow lexical declarations in case clauses (recommended)
    "no-div-regex": "off", // disallow division operators explicitly at beginning of regular expression
    "no-else-return": "off", // disallow `else` after a `return` in an `if`
    "no-empty-function": "off", // disallow use of empty functions
    "no-empty-pattern": "error", // disallow use of empty destructuring patterns (recommended)
    "no-eq-null": "off", // disallow comparisons to null without a type-checking operator
    "no-eval": "off", // disallow use of `eval()`
    "no-extend-native": "off", // disallow adding to native types
    "no-extra-bind": "off", // disallow unnecessary function binding
    "no-extra-label": "off", // disallow unnecessary labels
    "no-fallthrough": "error", // disallow fallthrough of `case` statements (recommended)
    "no-floating-decimal": "off", // disallow the use of leading or trailing decimal points in numeric literals
    "no-implicit-coercion": "off", // disallow the type conversions with shorter notations
    "no-implicit-globals": "off", // disallow `var` and named functions in global scope
    "no-implied-eval": "off", // disallow use of `eval()`-like methods
    "no-invalid-this": "off", // disallow `this` keywords outside of classes or class-like objects
    "no-iterator": "off", // disallow usage of `__iterator__` property
    "no-labels": "off", // disallow use of labeled statements
    "no-lone-blocks": "off", // disallow unnecessary nested blocks
    "no-loop-func": "off", // disallow creation of functions within loops
    "no-magic-numbers": "off", // disallow the use of magic numbers
    "no-multi-spaces": "error", // disallow use of multiple spaces (fixable)
    "no-multi-str": "off", // disallow use of multiline strings
    "no-native-reassign": "off", // disallow reassignments of native objects
    "no-new": "off", // disallow use of the `new` operator when not part of an assignment or comparison
    "no-new-func": "off", // disallow use of new operator for `Function` object
    "no-new-wrappers": "off", // disallow creating new instances of `String`,`Number`, and `Boolean`
    "no-octal": "error", // disallow use of octal literals (recommended)
    "no-octal-escape": "off", // disallow use of octal escape sequences in string literals, such as `var foo = "Copyright \251";`
    "no-param-reassign": "off", // disallow reassignment of function parameters
    "no-proto": "off", // disallow usage of `__proto__` property
    "no-redeclare": "error", // disallow declaring the same variable more than once (recommended)
    "no-return-assign": "off", // disallow use of assignment in `return` statement
    "no-script-url": "off", // disallow use of `javascript:` urls.
    "no-self-assign": "error", // disallow assignments where both sides are exactly the same (recommended)
    "no-self-compare": "off", // disallow comparisons where both sides are exactly the same
    "no-sequences": "off", // disallow use of the comma operator
    "no-throw-literal": "off", // restrict what can be thrown as an exception
    "no-unmodified-loop-condition": "off", // disallow unmodified conditions of loops
    "no-unused-expressions": "off", // disallow usage of expressions in statement position
    "no-unused-labels": "error", // disallow unused labels (recommended)
    "no-useless-call": "off", // disallow unnecessary `.call()` and `.apply()`
    "no-useless-concat": "off", // disallow unnecessary concatenation of literals or template literals
    "no-useless-escape": "off", // disallow unnecessary usage of escape character
    "no-void": "off", // disallow use of the `void` operator
    "no-warning-comments": "off", // disallow usage of configurable warning terms in comments: e.g. `TODO` or `FIXME`
    "no-with": "off", // disallow use of the `with` statement
    "radix": "off", // require use of the second argument for `parseInt()`
    "vars-on-top": "off", // require declaration of all vars at the top of their containing scope
    "wrap-iife": "off", // require immediate function invocation to be wrapped in parentheses
    "yoda": "off", // require or disallow Yoda conditions

    //
    // Strict Mode
    //
    // These rules relate to using strict mode and strict mode directives.
    //

    "strict": "off", // require effective use of strict mode directives

    //
    // Variables
    //
    // These rules have to do with variable declarations.
    //

    "init-declarations": "off", // enforce or disallow variable initializations at definition
    "no-catch-shadow": "off", // disallow the catch clause parameter name being the same as a variable in the outer scope
    "no-delete-var": "error", // disallow deletion of variables (recommended)
    "no-label-var": "off", // disallow labels that share a name with a variable
    "no-restricted-globals": "off", // restrict usage of specified global variables
    "no-shadow": "off", // disallow declaration of variables already declared in the outer scope
    "no-shadow-restricted-names": "off", // disallow shadowing of names such as `arguments`
    "no-undef": "error", // disallow use of undeclared variables unless mentioned in a `/*global */` block (recommended)
    "no-undef-init": "off", // disallow use of undefined when initializing variables
    "no-undefined": "off", // disallow use of `undefined` variable
    "no-unused-vars": ["error", {"vars": "all", "args": "none"}], // disallow declaration of variables that are not used in the code (recommended)
    "no-use-before-define": "off", // disallow use of variables before they are defined

    //
    // Node.js and CommonJS
    //
    // These rules are specific to JavaScript running on Node.js or using CommonJS in the browser.
    //

    "callback-return": "off", // enforce `return` after a callback
    "global-require": "off", // enforce `require()` on top-level module scope
    "handle-callback-err": "off", // enforce error handling in callbacks
    "no-mixed-requires": "off", // disallow mixing regular variable and require declarations
    "no-new-require": "off", // disallow use of `new` operator with the `require` function
    "no-path-concat": "off", // disallow string concatenation with `__dirname` and `__filename`
    "no-process-env": "off", // disallow use of `process.env`
    "no-process-exit": "off", // disallow `process.exit()`
    "no-restricted-modules": "off", // restrict usage of specified modules when loaded by `require` function
    "no-sync": "off", // disallow use of synchronous methods

    //
    // Stylistic Issues
    //
    // These rules are purely matters of style and are quite subjective.
    //

    "array-bracket-spacing": ["error", "never"], // enforce spacing inside array brackets (fixable)
    "block-spacing": "off", // disallow or enforce spaces inside of single line blocks (fixable)
    "brace-style": ["error", "1tbs", {"allowSingleLine": false}], // enforce one true brace style
    "camelcase": "off", // require camel case names
    "comma-spacing": ["error", {"before": false, "after": true}], // enforce spacing before and after comma (fixable)
    "comma-style": ["error", "last"], // enforce one true comma style
    "computed-property-spacing": "off", // require or disallow padding inside computed properties (fixable)
    "consistent-this": "off", // enforce consistent naming when capturing the current execution context
    "eol-last": ["error"], // enforce newline at the end of file, with no multiple empty lines (fixable)
    "func-names": "off", // require function expressions to have a name
    "func-style": "off", // enforce use of function declarations or expressions
    "id-blacklist": "off", // disallow certain identifiers to prevent them being used
    "id-length": "off", // enforce minimum and maximum identifier lengths (variable names, property names etc.)
    "id-match": "off", // require identifiers to match the provided regular expression
    "indent": ["error", 4, {"SwitchCase": 1}], // specify tab or space width for your code (fixable)
    "jsx-quotes": "off", // specify whether double or single quotes should be used in JSX attributes (fixable)
    "key-spacing": ["error", {"beforeColon": false, "afterColon": true}], // enforce spacing between keys and values in object literal properties
    "keyword-spacing": ["error", {"before": true, "after": true}], // enforce spacing before and after keywords
    "linebreak-style": ["error", "unix"], // enforce linebreak style (fixable)
    "lines-around-comment": "off", // enforce empty lines around comments
    "max-depth": "off", // specify the maximum depth that blocks can be nested
    "max-len": "off", // specify the maximum length of a line in your program
    "max-nested-callbacks": "off", // specify the maximum depth callbacks can be nested
    "max-params": "off", // specify the number of parameters that can be used in the function declaration
    "max-statements": "off", // specify the maximum number of statement allowed in a function
    "max-statements-per-line": "off", // specify the maximum number of statements allowed per line
    "new-cap": "off", // require a capital letter for constructors
    "new-parens": "error", // disallow the omission of parentheses when invoking a constructor with no arguments
    "newline-after-var": "off", // require or disallow an empty newline after variable declarations
    "newline-before-return": "off", // require newline before `return` statement
    "newline-per-chained-call": "off", // enforce newline after each call when chaining the calls
    "no-array-constructor": ["error"], // disallow use of the `Array` constructor
    "no-bitwise": "off", // disallow use of bitwise operators
    "no-continue": "off", // disallow use of the `continue` statement
    "no-inline-comments": "off", // disallow comments inline after code
    "no-lonely-if": "off", // disallow `if` as the only statement in an `else` block
    "no-mixed-spaces-and-tabs": "error", // disallow mixed spaces and tabs for indentation (recommended)
    "no-multiple-empty-lines": "off", // disallow multiple empty lines
    "no-negated-condition": "off", // disallow negated conditions
    "no-nested-ternary": "off", // disallow nested ternary expressions
    "no-new-object": "off", // disallow the use of the `Object` constructor
    "no-plusplus": "off", // disallow use of unary operators, `++` and `--`
    "no-restricted-syntax": "off", // disallow use of certain syntax in code
    "no-spaced-func": "off", // disallow space between function identifier and application (fixable)
    "no-ternary": "off", // disallow the use of ternary operators
    "no-trailing-spaces": "error", // disallow trailing whitespace at the end of lines (fixable)
    "no-underscore-dangle": "off", // disallow dangling underscores in identifiers
    "no-unneeded-ternary": "off", // disallow the use of ternary operators when a simpler alternative exists
    "no-whitespace-before-property": "off", // disallow whitespace before properties
    "object-curly-spacing": ["off", "never"], // require or disallow padding inside curly braces (fixable)
    "one-var": "off", // require or disallow one variable declaration per function
    "one-var-declaration-per-line": "off", // require or disallow an newline around variable declarations
    "operator-assignment": "off", // require assignment operator shorthand where possible or prohibit it entirely
    "operator-linebreak": "off", // enforce operators to be placed before or after line breaks
    "padded-blocks": "off", // enforce padding within blocks
    "quote-props": ["error", "as-needed", {"keywords": true}], // require quotes around object literal property names
    "quotes": ["error", "single", "avoid-escape"], // specify whether backticks, double or single quotes should be used (fixable)
    "require-jsdoc": "off", // require JSDoc comment
    "semi": ["error", "always"], // require or disallow use of semicolons instead of ASI (fixable)
    "semi-spacing": "error", // enforce spacing before and after semicolons (fixable)
    "sort-imports": "off", // enforce sorting import declarations within module
    "sort-vars": "off", // enforce sorting variables within the same declaration block
    "space-before-blocks": ["error", "always"], // require or disallow a space before blocks (fixable)
    "space-before-function-paren": ["error", "never"], // require or disallow a space before function opening parenthesis (fixable)
    "space-in-parens": ["error", "never"], // require or disallow spaces inside parentheses (fixable)
    "space-infix-ops": "error", // require spaces around operators (fixable)
    "space-unary-ops": ["error", {"words": true, "nonwords": false}], // require or disallow spaces before/after unary operators (fixable)
    "spaced-comment": ["error", "always", {"markers": ["!"]}], // require or disallow a space immediately following the `//` or `/*` in a comment (fixable)
    "wrap-regex": "off", // require regex literals to be wrapped in parentheses

    //
    // ECMAScript 6
    //
    // These rules are only relevant to ES6 environments.
    //

    "arrow-body-style": "off", // require braces in arrow function body
    "arrow-parens": "off", // require parens in arrow function arguments
    "arrow-spacing": "off", // require space before/after arrow function's arrow (fixable)
    "constructor-super": "error", // ensure calling of `super()` in constructors (recommended)
    "generator-star-spacing": "off", // enforce spacing around the `*` in generator functions (fixable)
    "no-class-assign": "error", // disallow modifying variables of class declarations (recommended)
    "no-confusing-arrow": "off", // disallow arrow functions where they could be confused with comparisons
    "no-const-assign": "error", // disallow modifying variables that are declared using `const` (recommended)
    "no-dupe-class-members": "error", // disallow duplicate name in class members (recommended)
    "no-duplicate-imports": "off", // disallow duplicate module imports
    "no-new-symbol": "error", // disallow use of the `new` operator with the `Symbol` object (recommended)
    "no-restricted-imports": "off", // restrict usage of specified modules when loaded by `import` declaration
    "no-this-before-super": "error", // disallow use of `this`/`super` before calling `super()` in constructors (recommended)
    "no-useless-constructor": "off", // disallow unnecessary constructor
    "no-var": "off", // require `let` or `const` instead of `var`
    "object-shorthand": "off", // require method and property shorthand syntax for object literals
    "prefer-arrow-callback": "off", // suggest using arrow functions as callbacks
    "prefer-const": "off", // suggest using `const` declaration for variables that are never reassigned after declared
    "prefer-reflect": "off", // suggest using Reflect methods where applicable
    "prefer-rest-params": "off", // suggest using the rest parameters instead of `arguments`
    "prefer-spread": "off", // suggest using the spread operator instead of `.apply()`
    "prefer-template": "off", // suggest using template literals instead of strings concatenation
    "require-yield": "off", // disallow generator functions that do not have `yield`
    "template-curly-spacing": "off", // enforce spacing around embedded expressions of template strings (fixable)
    "yield-star-spacing": "off", // enforce spacing around the `*` in `yield*` expressions (fixable)
    //

    //
    // Removed
    //
    // These rules existed in a previous version of ESLint but have since been replaced by newer rules.
    //

    "generator-star": 0, // enforce the position of the `*` in generator functions (replaced by [generator-star-spacing](generator-star-spacing.md))
    "global-strict": 0, // require or disallow the `"use strict"` pragma in the global scope (replaced by [strict](strict.md))
    "no-arrow-condition": 0, // disallow arrow functions where a condition is expected (replaced by [no-confusing-arrow](no-confusing-arrow.md) and [no-constant-condition](no-constant-condition.md))
    "no-comma-dangle": 0, // disallow trailing commas in object literals (replaced by [comma-dangle](comma-dangle.md))
    "no-empty-class": 0, // disallow the use of empty character classes in regular expressions (replaced by [no-empty-character-class](no-empty-character-class.md))
    "no-empty-label": 0, // disallow use of labels for anything other than loops and switches (replaced by [no-labels](no-labels.md))
    "no-extra-strict": 0, // disallow unnecessary use of `"use strict";` when already in strict mode (replaced by [strict](strict.md))
    "no-reserved-keys": 0, // disallow reserved words being used as object literal keys (replaced by [quote-props](quote-props.md))
    "no-space-before-semi": 0, // disallow space before semicolon (replaced by [semi-spacing](semi-spacing.md))
    "no-wrap-func": 0, // disallow wrapping of non-IIFE statements in parens (replaced by [no-extra-parens](no-extra-parens.md))
    "space-after-function-name": 0, // require a space after function names (replaced by [space-before-function-paren](space-before-function-paren.md))
    "space-after-keywords": 0, // require a space after certain keywords (fixable) (replaced by [keyword-spacing](keyword-spacing.md))
    "space-before-function-parentheses": 0, // require or disallow space before function parentheses (replaced by [space-before-function-paren](space-before-function-paren.md))
    "space-before-keywords": 0, // require a space before certain keywords (fixable) (replaced by [keyword-spacing](keyword-spacing.md))
    "space-in-brackets": 0, // require or disallow spaces inside brackets (replaced by [object-curly-spacing](object-curly-spacing.md) and [array-bracket-spacing](array-bracket-spacing.md))
    "space-return-throw-case": 0, // require a space after `return`, `throw`, and `case` (fixable) (replaced by [keyword-spacing](keyword-spacing.md))
    "space-unary-word-ops": 0, // require or disallow spaces before/after unary operators (replaced by [space-unary-ops](space-unary-ops.md))
    "spaced-line-comment": 0 // require or disallow a space immediately following the `//` in a line comment (replaced by [spaced-comment](spaced-comment.md))
  }
}