.eslintrc.js

module.exports = {
  root: true,
  plugins: [
    'chai-expect',
    'mocha'
  ],
  parserOptions: {
    ecmaVersion: 6,
  },
  extends: 'eslint:recommended',
  env: {
    browser: false,
    node: true,
    es6: true,
  },
  globals: {},
  rules: {
    /*** Possible Errors ***/

    // JSHint "boss"
    'no-cond-assign': [2, 'except-parens'],

    'no-console': 0,

    // JSHint "noempty", JSCS "disallowEmptyBlocks"
    'no-empty': 2,

    /*** Best Practices ***/

    // JSHint "curly"
    curly: 2,

    // JSHint "eqeqeq"
    eqeqeq: 2,

    // JSHint "forin", disabled already in .jshintrc
    'guard-for-in': 0,

    // JSHint "noarg"
    'no-caller': 2,

    // JSHint "eqnull"
    'no-eq-null': 2,

    // JSHint "evil"
    'no-eval': 2,

    // JSHint "nonew", disabled already in .jshintrc
    'no-new': 0,

    // JSHint "expr"
    'no-unused-expressions': [2, {
      allowShortCircuit: true,
      allowTernary: true,
    }],

    // JSHint "immed", disabled already in .jshintrc
    'wrap-iife': 0,

    yoda: 2,

    semi: 2,

    /*** Strict Mode ***/

    // JSHint "strict"
    strict: [2, 'global'],

    /*** Variables ***/

    // JSHint "undef"
    'no-undef': 2,

    // JSHint "unused"
    'no-unused-vars': 2,

    // JSHint "latedef"
    'no-use-before-define': [2, 'nofunc'],

    /*** Stylistic Issues ***/

    // JSHint "camelcase"
    camelcase: 0,

    'eol-last': 2,

    // JSHint "indent"
    indent: [2, 2, {
      SwitchCase: 1,
      VariableDeclarator: { var: 2, let: 2, const: 3 }
    }],

    'keyword-spacing': 2,

    // JSHint "laxbreak"
    'linebreak-style': [2, 'unix'],

    // JSHint "newcap
    'new-cap': [2, {
      properties: false,
    }],

    // JSHint "plusplus", disabled already in .jshintrc
    'no-plusplus': 0,

    // JSHint "trailing"
    'no-trailing-spaces': 2,

    'no-unneeded-ternary': 2,
    'space-before-blocks': 2,
    'space-in-parens': 2,
    'space-infix-ops': 2,
    'space-unary-ops': 2,
    'space-before-function-paren': ["error", { "anonymous": "never", "named": "never" }],

    // JSHint "quotmark"
    quotes: [2, 'single'],

    /*** chai-expect ***/

    'chai-expect/missing-assertion': 2,
    'chai-expect/no-inner-compare': 2,
    'mocha/no-exclusive-tests': 2
  },
};