.eslintrc.js

module.exports = {
  extends: ['airbnb', 'prettier', 'prettier/react'],
  parser: 'babel-eslint',
  env: {
    browser: true,
    jest: true,
  },
  rules: {
    'import/prefer-default-export': 0,
    'react/destructuring-assignment': 0,
    'react/jsx-filename-extension': 0,
    'react/prefer-stateless-function': 0,
    'react/sort-comp': 0,
  },

  overrides: [
    {
      files: ['**/*.ts?(x)'],
      parser: '@typescript-eslint/parser',
      settings: {
        'import/parsers': {
          '@typescript-eslint/parser': ['.ts', '.tsx'],
        },
        'import/resolver': {
          typescript: {},
        },
      },
      parserOptions: {
        ecmaVersion: 2018,
        sourceType: 'module',
        ecmaFeatures: {
          jsx: true,
        },

        // typescript-eslint specific options
        warnOnUnsupportedTypeScriptVersion: true,
      },
      plugins: ['@typescript-eslint'],
      // If adding a typescript-eslint version of an existing ESLint rule,
      // make sure to disable the ESLint rule here.
      rules: {
        // TypeScript's `noFallthroughCasesInSwitch` option is more robust (#6906)
        'default-case': 'off',
        // 'tsc' already handles this (https://github.com/typescript-eslint/typescript-eslint/issues/291)
        'no-dupe-class-members': 'off',
        // 'tsc' already handles this (https://github.com/typescript-eslint/typescript-eslint/issues/477)
        'no-undef': 'off',
        // Types will enforce the need to specify defaults
        'react/require-default-props': 'off',
        // Allow triple slash comments
        'spaced-comment': ['error', 'always', { markers: ['/'] }],

        // Add TypeScript specific rules (and turn off ESLint equivalents)
        '@typescript-eslint/consistent-type-assertions': 'warn',
        'no-array-constructor': 'off',
        '@typescript-eslint/no-array-constructor': 'warn',
        '@typescript-eslint/no-namespace': 'error',
        'no-use-before-define': 'off',
        '@typescript-eslint/no-use-before-define': [
          'warn',
          {
            functions: false,
            classes: false,
            variables: false,
            typedefs: false,
          },
        ],
        'no-unused-vars': 'off',
        '@typescript-eslint/no-unused-vars': [
          'warn',
          {
            args: 'none',
            ignoreRestSiblings: true,
          },
        ],
        'no-useless-constructor': 'off',
        '@typescript-eslint/no-useless-constructor': 'warn',
      },
    },
  ],
};