.eslintrc.js

module.exports = {
  env: {
    browser: true,
    es6: true,
  },
  extends: [
    'eslint:recommended',
    'plugin:react/recommended',
    'plugin:flowtype/recommended',
  ],
  parser: '@babel/eslint-parser',
  parserOptions: {
    requireConfigFile: false,
    ecmaFeatures: {
      jsx: true,
    },
    ecmaVersion: 12,
    sourceType: 'module',
  },
  plugins: ['react', 'flowtype'],
  rules: {
    'react/prop-types': 'off',
    'react/display-name': 'off',
    'no-unused-vars': 'warn',
    'flowtype/no-types-missing-file-annotation': 'off',
    'no-console': 'off',
  },
  settings: {
    react: {
      version: 'detect',
      flowVersion: '0.142.0', // Flow version
    },
    flowtype: {
      onlyFilesWithFlowAnnotation: true,
    },
  },
  overrides: [
    {
      files: [
        '.eslintrc.js',
        'gatsby-config.js',
        'gatsby-node.js',
        'scripts/*.js',
        'src/build-utils.js',
      ],
      env: {
        node: true,
      },
    },
  ],
};