.eslintrc.js

module.exports = {
  root: true,
  env: {
    browser: false,
    es6: true,
    node: true,
  },
  extends: [
    'eslint:recommended',
    'plugin:@typescript-eslint/eslint-recommended',
    'plugin:@typescript-eslint/recommended',
    'plugin:prettier/recommended',
  ],
  parser: '@typescript-eslint/parser',
  parserOptions: {
    sourceType: 'module',
    ecmaVersion: 2018,
  },
  plugins: ['@typescript-eslint', 'prettier'],
  rules: {
    'prettier/prettier': 'off',
    'array-callback-return': 'error',
    'brace-style': 'error',
    camelcase: [
      'error',
      {
        properties: 'never',
        allow: ['^UNSAFE_'],
      },
    ],
    curly: ['error', 'all'],
    'consistent-return': 'warn',
    eqeqeq: [
      'error',
      'always',
      {
        null: 'ignore',
      },
    ],
    'no-console': 'error',
    'no-lonely-if': 'error',
    'no-multi-spaces': 'error',
    'no-nested-ternary': 'error',
    'no-restricted-globals': ['error', 'event'],
    'no-restricted-properties': 'error',
    'no-restricted-syntax': ['error', 'LabeledStatement', 'WithStatement'],
    'no-unused-vars': [
      'error',
      {
        argsIgnorePattern: '^_',
        varsIgnorePattern: '^__',
      },
    ],
    'one-var': ['error', 'never'],
    'padding-line-between-statements': [
      'error',
      {
        blankLine: 'always',
        prev: '*',
        next: 'return',
      },
      {
        blankLine: 'always',
        prev: 'block-like',
        next: '*',
      },
    ],
    'prefer-const': [
      'error',
      {
        destructuring: 'all',
      },
    ],
    'prefer-rest-params': 'error',
  },
  overrides: [
    {
      files: ['**/*.ts', '**/*.tsx'],
      extends: ['plugin:@typescript-eslint/recommended'],
      rules: {
        'consistent-return': 'off',
        'array-callback-return': 'off',
        'no-shadow': 'off',
        '@typescript-eslint/no-shadow': 'error',
        '@typescript-eslint/no-namespace': [
          'error',
          {
            allowDeclarations: true,
          },
        ],
        '@typescript-eslint/no-unused-expressions': ['error'],
        '@typescript-eslint/no-unused-vars': [
          'error',
          {
            argsIgnorePattern: '^_',
            varsIgnorePattern: '^__',
          },
        ],
        '@typescript-eslint/ban-types': 'warn',
        '@typescript-eslint/no-empty-interface': 'off',
        '@typescript-eslint/no-empty-function': 'off',
        '@typescript-eslint/no-inferrable-types': 'off',
        '@typescript-eslint/no-non-null-assertion': 'warn',
        '@typescript-eslint/array-type': [
          'error',
          {
            default: 'generic',
          },
        ],
        '@typescript-eslint/no-redeclare': 'error',
      },
    },
  ],
};