.eslintrc.json

{
  "env": {
    "es6": true,
    "node": true,
    "mocha": true
  },
  "extends": [
    "eslint:recommended",
    "plugin:import-order/recommended"
  ],
  "parserOptions": {
    "ecmaVersion": 8,
    "sourceType": "script"
  },
  "plugins": [
    "import-order"
  ],
  "rules": {
    "indent": [ // indentation is 2 spaces
      "error",
      2,
      {
        "SwitchCase": 1  // indent case clauses with 2 spaces with respect to switch statements
      }
    ],
    "strict": [ // use strict mode
      "error",
      "global"
    ],
    /*"valid-jsdoc": [ // enforce valid JSDoc comments // TODO enable
      "error"
    ],*/
    "no-unused-vars": 0, /*[ // TODO enable
      "error"
    ],*/
    "no-constant-condition": 0, /*[ // TODO enable
      "error"
    ],*/
    "semi": [ // semicolons are required
      "error",
      "always"
    ],
    "max-len": [ // max line length is 100 chars (except for comments)
      "error",
      100, {
        "ignoreComments": true
      }
    ],
    "eol-last": [ // \n is required at the end of the file
      "error",
      "always"
    ],
    "camelcase": [ // enforce camelcase style for variable names and property names
      "error", {
        "properties": "always"
      }
    ],
    "dot-notation": [ // always use the dot notation to access properties, except if property contains '_'
      "error", {
        "allowPattern": "^.*_.*$"
      }
    ],
    "quotes": [ // use single quotes (or backticks if there is a substitution)
      "error",
      "single"
    ],
    "comma-dangle": [ // no trailing commas in object or array literals
      "error",
      "never"
    ],
    "no-multi-str": [ // no multi line strings using \
      "error"
    ],
    "no-multiple-empty-lines": [
      "error"
    ],
    "no-trailing-spaces": [
      "error"
    ],
    "no-mixed-spaces-and-tabs": [
      "error"
    ],
    "curly": [ // `if (foo) foo++` is not allowed. Curly braces are always required
      "error",
      "all"
    ],
    "brace-style": [ // use K&R style
      "error",
      "1tbs", {
        "allowSingleLine": true // `if (foo) {foo++}` is allowed
      }
    ],
    "keyword-spacing": [ // in `} else {` both spaces are required (in general, around keywords)
      "error", {
        "before": true,
        "after": true,
        "overrides": {
          "catch": {
            "before": true,
            "after": false
          }
        }
      }
    ],
    "space-before-blocks": [ // in `if (foo) {` the second space is required
      "error",
      "always"
    ],
    "arrow-spacing": [ // in `(foo) => {` both spaces are required
      "error", {
        "before": true,
        "after": true
      }
    ],
    "operator-linebreak": [ // linebreak goes after the operator except for '?' and ':'
      "error",
      "after", {
        "overrides": {
          "?": "before",
          ":": "before"
        }
      }
    ],
    "space-unary-ops": [ // space is required for new, delete, etc. but not for +, -, ++, --, etc.
      "error", {
        "words": true,
        "nonwords": false,
        "overrides": {
          "typeof": false // also no space for typeof(...)
        }
      }
    ],
    "space-infix-ops": [ // space is required around infix operators, e.g: 'a + b'
      "error"
    ],
    "comma-spacing": [ // space is required after a comma
      "error", {
        "after": true
      }
    ],
    "array-bracket-spacing": [ // '[ x, y ]' is not allowed
      "error",
      "never"
    ],
    "space-in-parens": [ // '( x + y )' is not allowed, use '(x + y)'
      "error",
      "never"
    ],
    "key-spacing": [ // `{property :'value'}` is not allowed, use `{property: 'value'}`
      "error", {
        "beforeColon": false,
        "afterColon": true,
        "mode": "strict"
      }
    ],
    "yoda": [ // disallow yoda conditions, e.g. `(true === foo)`
      "error",
      "never"
    ],
    "no-with": [ // the with statements is not allowed
      "error"
    ],
    "linebreak-style": [ // use unix linebreak '\n'
      "error",
      "unix"
    ],
    "wrap-iife": [ // require IIFE to be wrapped in parenthesis
      "error"
    ],
    "func-call-spacing": [ // no space between the function name and the opening parenthesis on invocation
      "error",
      "never"
    ],
    "space-before-function-paren": [ // no space between the function name and the opening parenthesis on declaration
      "error", {
        "anonymous": "never",
        "named": "never"
      }
    ],
    "no-cond-assign": [ // no assignment operators in if, for and while except if enclosed in parentheses
      "error",
      "except-parens"
    ],
    "no-console": 0, // `console.log(...)` is allowed
    "import-order/import-order": 0 /*[ // enforce import order ("builtin", "external", "parent", "sibling", "index")
      "error" // TODO enable
    ]*/
  }
}