.eslintrc.js

module.exports = {
  parser: 'babel-eslint',
  env: {
    jest: true,
    browser: true,
    node: true,
    es6: true
  },
  extends: ['eslint:recommended'],
  parserOptions: {
    ecmaFeatures: {
      experimentalObjectRestSpread: true
    },
    sourceType: 'module'
  },
  plugins: ['flowtype'],
  rules: {
    'flowtype/define-flow-type': 1,
    'flowtype/require-valid-file-annotation': ['error', 'always'],

    // handled by prettier:
    // indent: ['error', 2],
    // quotes: ['error', 'single', 'avoid-escape'],
    // semi: ['error', 'always'],
    // 'brace-style': ['error'],
    // 'array-bracket-spacing': ['error', 'never'],
    // 'block-spacing': ['error', 'always'],
    // 'no-spaced-func': ['error'],
    // 'no-whitespace-before-property': ['error'],
    // 'space-before-blocks': ['error', 'always'],
    // 'keyword-spacing': ['error'],

    'linebreak-style': ['error', 'unix'],
    'no-var': ['error']
  }
};