index.js

const process = require('process');

module.exports = {
  parserOptions: {
    sourceType: 'script'
  },
  reportUnusedDisableDirectives: true,
  rules: {
    // eslint-config-xo-lass
    camelcase: 'off',
    'capitalized-comments': 'off',
    'import/extensions': 'off',
    'unicorn/catch-error-name': ['error', { name: 'err' }],
    'unicorn/import-style': 'off',
    'unicorn/prefer-module': 'off',
    'unicorn/prevent-abbreviations': 'off',
    'unicorn/no-this-assignment': 'off',
    'unicorn/numeric-separators-style': 'off',
    quotes: ['error', 'single', { avoidEscape: true }],

    // eslint-config-xo
    'for-direction': 'error',
    'getter-return': 'error',
    'no-async-promise-executor': 'error',
    'no-await-in-loop': 'error',
    'no-compare-neg-zero': 'error',
    'no-cond-assign': 'error',
    'no-constant-condition': 'error',
    'no-control-regex': 'error',
    'no-debugger': 'error',
    'no-dupe-args': 'error',
    'no-dupe-else-if': 'error',
    'no-dupe-keys': 'error',
    'no-duplicate-case': 'error',
    'no-empty-character-class': 'error',
    'no-empty': [
      'error',
      {
        allowEmptyCatch: true
      }
    ],
    'no-ex-assign': 'error',
    'no-extra-boolean-cast': 'error',
    // Disabled because of https://github.com/eslint/eslint/issues/6028
    // 'no-extra-parens': [
    // 	'error',
    // 	'all',
    // 	{
    // 		conditionalAssign: false,
    // 		nestedBinaryExpressions: false,
    // 		ignoreJSX: 'multi-line'
    // 	}
    // ],
    'no-extra-semi': 'error',
    'no-func-assign': 'error',
    'no-import-assign': 'error',
    'no-inner-declarations': 'error',
    'no-invalid-regexp': 'error',
    'no-irregular-whitespace': 'error',
    'no-loss-of-precision': 'error',
    'no-misleading-character-class': 'error',
    'no-obj-calls': 'error',
    'no-promise-executor-return': 'error',
    'no-prototype-builtins': 'error',
    'no-regex-spaces': 'error',
    'no-setter-return': 'error',
    'no-sparse-arrays': 'error',
    'no-template-curly-in-string': 'error',
    'no-unreachable': 'error',
    'no-unreachable-loop': 'error',
    'no-unsafe-finally': 'error',
    'no-unsafe-negation': [
      'error',
      {
        enforceForOrderingRelations: true
      }
    ],
    'no-unsafe-optional-chaining': [
      'error',
      {
        disallowArithmeticOperators: true
      }
    ],
    'no-useless-backreference': 'error',
    'use-isnan': 'error',
    'valid-typeof': [
      'error',
      {
        requireStringLiterals: false
      }
    ],
    'no-unexpected-multiline': 'error',
    'accessor-pairs': [
      'error',
      {
        enforceForClassMembers: true
      }
    ],
    'array-callback-return': [
      'error',
      {
        allowImplicit: true
      }
    ],
    'block-scoped-var': 'error',
    complexity: 'warn',
    'default-case': 'error',
    'default-case-last': 'error',
    'dot-notation': 'error',
    'dot-location': ['error', 'property'],
    eqeqeq: 'error',
    'grouped-accessor-pairs': ['error', 'getBeforeSet'],
    'guard-for-in': 'error',
    'no-alert': 'error',
    'no-caller': 'error',
    'no-case-declarations': 'error',
    'no-constructor-return': 'error',
    'no-else-return': [
      'error',
      {
        allowElseIf: false
      }
    ],
    'no-empty-pattern': 'error',
    'no-eq-null': 'error',
    'no-eval': 'error',
    'no-extend-native': 'error',
    'no-extra-bind': 'error',
    'no-extra-label': 'error',
    'no-fallthrough': 'error',
    'no-floating-decimal': 'error',
    'no-global-assign': 'error',
    'no-implicit-coercion': 'error',
    'no-implicit-globals': 'error',
    'no-implied-eval': 'error',
    'no-iterator': 'error',
    'no-labels': 'error',
    'no-lone-blocks': 'error',
    'no-multi-spaces': 'error',
    'no-multi-str': 'error',
    'no-new-func': 'error',
    'no-new-wrappers': 'error',
    'no-nonoctal-decimal-escape': 'error',
    'no-new': 'error',
    'no-octal-escape': 'error',
    'no-octal': 'error',
    'no-proto': 'error',
    'no-redeclare': 'error',
    'no-return-assign': ['error', 'always'],
    'no-return-await': 'error',
    'no-script-url': 'error',
    'no-self-assign': [
      'error',
      {
        props: true
      }
    ],
    'no-self-compare': 'error',
    'no-sequences': 'error',
    'no-throw-literal': 'error',
    'no-unmodified-loop-condition': 'error',
    'no-unused-expressions': [
      'error',
      {
        enforceForJSX: true
      }
    ],
    'no-unused-labels': 'error',
    'no-useless-call': 'error',
    'no-useless-catch': 'error',
    'no-useless-concat': 'error',
    'no-useless-escape': 'error',
    'no-useless-return': 'error',
    'no-void': 'error',
    'no-warning-comments': 'warn',
    'no-with': 'error',

    // Disabled for now as Firefox doesn't support named capture groups and I'm tired of getting issues about the use of named capture groups...
    // 'prefer-named-capture-group': 'error'

    'prefer-promise-reject-errors': [
      'error',
      {
        allowEmptyReject: true
      }
    ],
    'prefer-regex-literals': 'error',
    radix: 'error',

    // Disabled for now as it causes too much churn
    // TODO: Enable it in the future when I have time to deal with
    // the churn and the rule is stable and has an autofixer.
    // Still doesn't have a fixer as of ESLint 7.24.0.
    // 'require-unicode-regexp': 'error',

    'wrap-iife': [
      'error',
      'inside',
      {
        functionPrototypeMethods: true
      }
    ],
    yoda: 'error',
    'no-delete-var': 'error',
    'no-label-var': 'error',
    'no-restricted-globals': ['error', 'event'],
    'no-shadow-restricted-names': 'error',
    'no-undef-init': 'error',
    'no-undef': [
      'error',
      {
        typeof: true
      }
    ],
    'no-unused-vars': [
      'error',
      {
        vars: 'all',
        args: 'after-used',
        ignoreRestSiblings: true,
        argsIgnorePattern: /^_/.source,
        caughtErrors: 'all',
        caughtErrorsIgnorePattern: /^_$/.source
      }
    ],
    'no-buffer-constructor': 'error',
    'no-restricted-imports': [
      'error',
      'domain',
      'freelist',
      'smalloc',
      'punycode',
      'sys',
      'querystring',
      'colors'
    ],
    'array-bracket-newline': ['error', 'consistent'],
    'array-bracket-spacing': ['error', 'never'],
    'array-element-newline': ['error', 'consistent'],
    'brace-style': [
      'error',
      '1tbs',
      {
        allowSingleLine: false
      }
    ],
    'comma-spacing': [
      'error',
      {
        before: false,
        after: true
      }
    ],
    'comma-style': ['error', 'last'],
    'computed-property-spacing': [
      'error',
      'never',
      {
        enforceForClassMembers: true
      }
    ],
    'eol-last': 'error',
    'func-call-spacing': ['error', 'never'],
    'func-name-matching': [
      'error',
      {
        considerPropertyDescriptor: true
      }
    ],
    'func-names': ['error', 'never'],
    'function-call-argument-newline': ['error', 'consistent'],
    'jsx-quotes': ['error', 'prefer-single'],
    'key-spacing': [
      'error',
      {
        beforeColon: false,
        afterColon: true
      }
    ],
    'keyword-spacing': 'error',
    'linebreak-style': [process.platform === 'win32' ? 'off' : 'error', 'unix'],
    'lines-between-class-members': [
      'error',
      'always',
      {
        // Workaround to allow class fields to not have lines between them.
        // TODO: Get ESLint to add an option to ignore class fields.
        exceptAfterSingleLine: true
      }
    ],
    'max-depth': 'warn',
    'max-nested-callbacks': ['warn', 4],
    'max-params': [
      'warn',
      {
        max: 4
      }
    ],
    'max-statements-per-line': 'error',
    'new-cap': [
      'error',
      {
        newIsCap: true,
        capIsNew: true
      }
    ],
    'new-parens': 'error',
    'no-array-constructor': 'error',
    'no-bitwise': 'error',
    'no-lonely-if': 'error',
    'no-mixed-operators': 'error',
    'no-mixed-spaces-and-tabs': 'error',
    'no-multi-assign': 'error',
    'no-multiple-empty-lines': [
      'error',
      {
        max: 1
      }
    ],
    'no-negated-condition': 'error',
    'no-new-object': 'error',
    'no-whitespace-before-property': 'error',
    'no-trailing-spaces': 'error',
    'no-unneeded-ternary': 'error',
    'object-curly-spacing': ['error', 'always'],
    // Disabled because of https://github.com/xojs/eslint-config-xo/issues/27
    // 'object-property-newline': 'error',
    'one-var': ['error', 'never'],
    'one-var-declaration-per-line': 'error',
    'operator-assignment': ['error', 'always'],
    'padded-blocks': [
      'error',
      'never',
      {
        allowSingleLineBlocks: false
      }
    ],
    'padding-line-between-statements': [
      'error',
      {
        blankLine: 'always',
        prev: 'multiline-block-like',
        next: '*'
      }
    ],
    'prefer-exponentiation-operator': 'error',
    'prefer-object-spread': 'error',
    'quote-props': ['error', 'as-needed'],
    'semi-spacing': [
      'error',
      {
        before: false,
        after: true
      }
    ],
    'semi-style': ['error', 'last'],
    semi: ['error', 'always'],
    'space-before-blocks': ['error', 'always'],
    'space-before-function-paren': [
      'error',
      {
        anonymous: 'always',
        named: 'never',
        asyncArrow: 'always'
      }
    ],
    'space-in-parens': ['error', 'never'],
    'space-infix-ops': 'error',
    'space-unary-ops': 'error',
    'spaced-comment': [
      'error',
      'always',
      {
        line: {
          exceptions: ['-', '+', '*'],
          markers: ['!', '/', '=>']
        },
        block: {
          exceptions: ['-', '+', '*'],
          markers: ['!', '*'],
          balanced: true
        }
      }
    ],
    'switch-colon-spacing': [
      'error',
      {
        after: true,
        before: false
      }
    ],
    'template-tag-spacing': ['error', 'never'],
    'unicode-bom': ['error', 'never'],
    'arrow-body-style': 'error',
    'arrow-spacing': [
      'error',
      {
        before: true,
        after: true
      }
    ],
    'constructor-super': 'error',
    'generator-star-spacing': ['error', 'both'],
    'no-class-assign': 'error',
    'no-const-assign': 'error',
    'no-dupe-class-members': 'error',
    'no-new-symbol': 'error',
    'no-this-before-super': 'error',
    'no-useless-computed-key': [
      'error',
      {
        enforceForClassMembers: true
      }
    ],
    'no-useless-constructor': 'error',
    'no-useless-rename': 'error',
    'no-var': 'error',
    'object-shorthand': [
      'error',
      'always',
      {
        avoidExplicitReturnArrows: true
      }
    ],
    'prefer-arrow-callback': [
      'error',
      {
        allowNamedFunctions: true
      }
    ],
    'prefer-const': [
      'error',
      {
        destructuring: 'all'
      }
    ],
    'prefer-destructuring': [
      'error',
      {
        // `array` is disabled because it forces destructuring on
        // stupid stuff like `foo.bar = process.argv[2];`
        // TODO: Open ESLint issue about this
        VariableDeclarator: {
          array: false,
          object: true
        },
        AssignmentExpression: {
          array: false,

          // Disabled because object assignment destructuring requires parens wrapping:
          // `let foo; ({foo} = object);`
          object: false
        }
      },
      {
        enforceForRenamedProperties: false
      }
    ],
    'prefer-numeric-literals': 'error',

    // TODO: Enable when targeting Node.js 16.
    // 'prefer-object-has-own': 'error',

    'prefer-rest-params': 'error',
    'prefer-spread': 'error',
    'require-yield': 'error',
    'rest-spread-spacing': ['error', 'never'],
    'symbol-description': 'error',
    'template-curly-spacing': 'error',
    'yield-star-spacing': ['error', 'both']
  }
};