.eslintrc.js

module.exports = {
  env: {
    browser: true,
    es6: true,
    node: true,
    mocha: true
  },
  globals: {
    expect: true
  },
  parser: 'babel-eslint',
  parserOptions: {
    ecmaVersion: 6,
    ecmaFeatures: {
      experimentalObjectRestSpread: true,
      jsx: true
    },
    sourceType: 'module'
  },
  plugins: ['react'],
  extends: ['eslint:recommended', 'plugin:react/recommended'],
  rules: {
    'arrow-spacing': 'error',
    'block-spacing': 'error',
    'comma-dangle': 'off',
    'comma-spacing': 'error',
    'comma-style': 'error',
    curly: 'error',
    'dot-notation': 'error',
    eqeqeq: ['error', 'smart'],
    'eol-last': 'error',
    'key-spacing': 'error',
    'keyword-spacing': 'error',
    'linebreak-style': ['error', 'unix'],
    'no-console': 'off',
    'no-param-reassign': 'error',
    'no-tabs': 'error',
    'no-trailing-spaces': 'error',
    'no-underscore-dangle': 'error',
    'no-var': 'error',
    'no-whitespace-before-property': 'error',
    'prefer-const': 'error',
    semi: ['error', 'always'],
    'semi-spacing': 'error',
    'space-before-blocks': 'error',
    'space-before-function-paren': ['error', 'never'],
    'space-in-parens': 'error',
    'react/display-name': 'off'
  }
};