.eslintrc.js

module.exports = {
  root: true,
  env: {
    es6: true,
    node: true,
    browser: true,
    jest: true,
  },
  extends: [
    'airbnb',
    'plugin:@typescript-eslint/eslint-recommended',
    'prettier',
    'prettier/@typescript-eslint',
    'plugin:prettier/recommended',
  ],
  parser: '@typescript-eslint/parser',
  plugins: ['@typescript-eslint', 'prettier'],
  parserOptions: {
    ecmaVersion: 2018,
    sourceType: 'module',
    ecmaFeatures: {
      impliedStrict: true,
      jsx: true,
    },
  },
  rules: {
    'dot-notation': 'off',
    'jsx-a11y/anchor-is-valid': 'off',
    'prettier/prettier': 'error',
    'react/jsx-closing-tag-location': 'off',
    'react/jsx-filename-extension': ['error', { extensions: ['.jsx', '.tsx'] }],
    'react/jsx-one-expression-per-line': 'off',
    'react/jsx-props-no-spreading': 'off',
    'react/prop-types': 'off',
  },
  settings: {
    'import/resolver': {
      node: {
        extensions: ['.js', '.jsx', '.ts', '.tsx'],
      },
      typescript: {},
    },
    'import/extensions': ['.js', '.mjs', '.jsx', '.ts', '.tsx'],
  },
  overrides: [
    {
      files: ['**/*.ts', '**/*.tsx'],
      parserOptions: {
        ecmaVersion: 2018,
        sourceType: 'module',

        // typescript-eslint specific options
        warnOnUnsupportedTypeScriptVersion: true,
      },
      rules: {
        'no-undef': 'off',
        'no-unused-vars': 'off',
        'import/extensions': [
          'error',
          'ignorePackages',
          {
            js: 'never',
            mjs: 'never',
            jsx: 'never',
            ts: 'never',
            tsx: 'never',
          },
        ],
        '@typescript-eslint/camelcase': 'off',
        '@typescript-eslint/explicit-function-return-type': ['off'],
        '@typescript-eslint/no-unused-vars': [
          'warn',
          { argsIgnorePattern: '^_', varsIgnorePattern: '^_' },
        ],
      },
    },
    {
      files: ['.eslintrc.js', '*.config.js'],
      parserOptions: { sourceType: 'script' },
      env: { node: true },
    },
  ],
};