.eslintrc.js

module.exports = {
  parserOptions: {
    ecmaVersion: 2018,
  },
  env: {
    browser: true,
    es6: true,
  },
  rules: {
    'no-console': 'off',
    'no-extra-parens': ['error', 'all'],
    'array-callback-return': 'error',
    curly: 'error',
    'default-case': 'warn',
    eqeqeq: ['error', 'always'],
    'guard-for-in': 'warn',
    'no-caller': 'error',
    'no-empty-function': 'error',
    'no-eval': 'error',
    'no-extra-bind': 'error',
    'no-floating-decimal': 'error',
    'no-lone-blocks': 'error',
    'no-multi-spaces': 'error',
    'no-new': 'warn',
    'no-return-assign': 'error',
    'no-self-compare': 'error',
    'no-useless-call': 'error',
    'no-undef-init': 'error',
    'block-spacing': 'error',
    'brace-style': 'error',
    'func-call-spacing': ['error', 'never'],
    'max-len': ['error', {code: 120, ignoreComments: true}],
    'new-cap': ['error', {newIsCap: true}],
    'new-parens': 'error',
    'no-nested-ternary': 'error',
    'no-unneeded-ternary': 'error',
    quotes: [
      'warn',
      'single',
      {avoidEscape: true, allowTemplateLiterals: true},
    ],
    'arrow-spacing': ['error', {before: true, after: true}],
    'no-useless-computed-key': 'error',
    'no-useless-constructor': 'error',
    'no-prototype-builtins': 'off',
    'no-var': 'warn',
    'no-unused-vars': ['error', {vars: 'local'}],
    'no-magic-numbers': ['warn', {ignore: [0, 1]}],
  },
};