.eslintrc.yml

---
# SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
env:
  es6: true
plugins:
  - unicorn
extends: 'eslint:recommended'
rules:
  array-bracket-newline: # just styling
    - warn
    - consistent
  array-bracket-spacing: # just styling
    - warn
    - never
  array-callback-return: # catch falsy code. return is always needed in array callbacks
    - error
  arrow-parens: # catch typos of => vs. >=
    - error
  arrow-spacing: # just styling
    - warn
  block-scoped-var: # causes nasty errors, especially in for loops with 'i' vars
    - error
  block-spacing: # just styling
    - warn
  brace-style: # just styling
    - warn
  comma-dangle: # just styling
    - warn
    - arrays: always-multiline
      objects: always-multiline
      functions: always-multiline
  comma-spacing: # just styling
    - warn
    - before: false
      after: true
  comma-style: # just styling
    - warn
    - last
  computed-property-spacing: # just styling
    - warn
  consistent-return: # this is an error on most other languages
    - error
  curly: # enforce braces around e.g. if blocks to minimize bugs
    - error
  dot-location: # just styling
    - warn
    - property
  eol-last: # just styling
    - warn
  eqeqeq: # prefer === to ==, mitigates programming mistakes
    - error
  func-call-spacing: # just styling
    - warn
  func-name-matching: # mitigates typos
    - error
  func-style: # mitigate 'this' scoping mistakes
    - error
    - declaration
  indent: # gnome-shell defaults, just styling
    - warn
    - 4
    - ignoredNodes:
      # Allow not indenting the body of GObject.registerClass, since in the
      # future it's intended to be a decorator
      - 'CallExpression[callee.object.name=GObject][callee.property.name=registerClass] > ClassExpression:first-child'
      # Allow dedenting chained member expressions
      MemberExpression: 'off'
  key-spacing: # just styling
    - warn
    - beforeColon: false
      afterColon: true
  keyword-spacing: # just styling
    - warn
    - before: true
      after: true
  linebreak-style: # can cause issues on some systems, better do this right
    - error
    - unix
  lines-between-class-members: # just styling
    - warn
  max-nested-callbacks: # just styling
    - warn
  max-statements-per-line: # just styling
    - warn
  new-parens: # just styling
    - warn
  no-array-constructor: # just styling
    - warn
  no-await-in-loop: # joining promises is preferred
    - warn
  no-caller: # no fiddling with arguments.caller/callee please
    - error
  no-constant-condition: # mostly typos
    - error
    - checkLoops: false
  no-div-regex: # /= at beginning of regex is nasty as it is also an assignment
    - error
  no-empty: # mostly styling
    - warn
    - allowEmptyCatch: true
  no-eq-null:
    - warn
  no-extra-bind: # cleanup the .bind(...) mess
    - warn
  no-extra-parens: # just styling
    - warn
    - all
    - conditionalAssign: false
      nestedBinaryExpressions: false
      returnAssign: false
  no-extra-boolean-cast:
    - warn
  no-func-assign:
    - warn
  no-implicit-coercion: # just use constructors instead
    - error
    - allow:
      - '!!'
  no-invalid-this: # this outside a class is probably a mistake
    - error
  no-iterator: # prototype.__iterator__ is not available in gjs
    - error
  no-label-var: # labels should not have the same name as a variable
    - error
  no-lonely-if: # just styling
    - warn
  no-loop-func: # anonymous functions create closures within loops which are hard to get right
    - error
  no-nested-ternary: # just styling, but please ... don't
    - warn
  no-new-object: # just styling
    - warn
  no-new-wrappers: # just styling
    - warn
  no-octal-escape: # just use unicode, octals are deprecated
    - error
  no-proto: # is deprecated
    - error
  no-restricted-properties: # gjs stuff
    - error
    - object: Lang
      property: copyProperties
      message: Use Object.assign()
    - object: Lang
      property: bind
      message: Use arrow notation or Function.prototype.bind()
    - object: Lang
      property: Class
      message: Use ES6 classes
  no-restricted-syntax: # just styling
    - warn
    - selector: >-
        MethodDefinition[key.name="_init"] >
        FunctionExpression[params.length=1] >
        BlockStatement[body.length=1]
        CallExpression[arguments.length=1][callee.object.type="Super"][callee.property.name="_init"] >
        Identifier:first-child
      message: _init() that only calls super._init() is unnecessary
    - selector: >-
        MethodDefinition[key.name="_init"] >
        FunctionExpression[params.length=0] >
        BlockStatement[body.length=1]
        CallExpression[arguments.length=0][callee.object.type="Super"][callee.property.name="_init"]
      message: _init() that only calls super._init() is unnecessary
    - selector: BinaryExpression[operator="instanceof"][right.name="Array"]
      message: Use Array.isArray()
  no-return-assign: # probably a typo or at least really bad style
    - error
  no-return-await: # just styling
    - warn
  no-self-compare: # will always be true
    - error
  no-shadow-restricted-names: # don't do this
    - error
  no-spaced-func: # just styling
    - warn
  no-tabs: # just styling
    - warn
  no-template-curly-in-string: # prevent wrong syntax for string interpolation
    - error
  no-throw-literal: # only throw new Error(...)
    - error
  no-trailing-spaces: # just styling
    - warn
  no-undefined: # just styling
    - warn
  no-undef-init: # this is bad
    - error
  no-unneeded-ternary: # just styling
    - warn
  no-unused-expressions: # just styling
    - warn
  no-unused-vars: # just styling
    - warn
    # Vars use a suffix _ instead of a prefix because of file-scope private vars
    - varsIgnorePattern: ^_
      argsIgnorePattern: ^_
  no-useless-call: # just styling
    - warn
  no-useless-computed-key: # just styling
    - warn
  no-useless-concat: # just styling
    - warn
  no-useless-constructor: # just styling
    - warn
  no-useless-rename: # just styling
    - warn
  no-useless-return: # just styling
    - warn
  no-whitespace-before-property: # just styling
    - warn
  no-with: # don't use this shit
    - error
  object-curly-newline: # just styling
    - warn
    - consistent: true
  object-curly-spacing: # just styling
    - warn
  object-shorthand: # just styling
    - warn
  operator-assignment: # just styling
    - warn
  operator-linebreak: # just styling
    - warn
  padded-blocks: # just styling
    - warn
    - never
  prefer-numeric-literals: # this is hacky, but just styling
    - warn
  prefer-promise-reject-errors: # please use Error
    - error
  prefer-rest-params: # do not use arguments
    - error
  prefer-spread: # do not use apply if possible
    - error
  prefer-template: # interpolated strings are far more readable
    - error
  quotes: # I'm a C-guy... single quotes are for char
    - warn
    - double
    - avoidEscape: true # but avoiding escapes is ok
  require-await: # async fns should contains awaits
    - warn
  rest-spread-spacing: # just styling
    - warn
  semi: # this is an error in most other languages, won't hurt
    - error
    - always
  semi-spacing: # just styling
    - warn
    - before: false
      after: true
  semi-style: # just styling
    - warn
  space-before-blocks: # just styling
    - warn
  space-before-function-paren: # just styling
    - warn
    - named: never
      # for `function ()` and `async () =>`, preserve space around keywords
      anonymous: always
      asyncArrow: always
  space-in-parens: # just styling
    - warn
  space-infix-ops: # just styling
    - warn
    - int32Hint: false
  space-unary-ops: # just styling
    - warn
  spaced-comment: # just styling
    - warn
  switch-colon-spacing: # just styling
    - warn
  symbol-description: # make debugging easier
    - warn
  template-curly-spacing: # just styling
    - warn
  template-tag-spacing: # just styling
    - warn
  unicode-bom: # stupid editors, don't to this
    - error
  wrap-iife: # just styling
    - warn
    - inside
  yield-star-spacing: # just styling
    - warn
  yoda: # just styling
    - warn
  unicorn/no-this-assignment:
    - warn
globals:
  ARGV: readonly
  Debugger: readonly
  GIRepositoryGType: readonly
  globalThis: readonly
  imports: readonly
  Intl: readonly
  log: readonly
  logError: readonly
  print: readonly
  printerr: readonly
parserOptions:
  ecmaVersion: 2020