.eslintrc

---
parser: babel-eslint

env:
  browser: true
  node: true
  jest: true
  jasmine: true
  es6: true

plugins:
  - react

globals:
  __DEV__: true
  chrome: true
  window: true

  # Flow globals
  $Enum: true
  $FixMe: true
  $FlowFixMe: true
  $FlowIssue: true
  $Keys: true
  Iterator: true
  IteratorResult: true

  # Flow globals for React
  ReactClass: true
  ReactElement: true
  SyntheticClipboardEvent: true
  SyntheticCompositionEvent: true
  SyntheticDragEvent: true
  SyntheticEvent: true
  SyntheticFocusEvent: true
  SyntheticInputEvent: true
  SyntheticKeyboardEvent: true
  SyntheticMouseEvent: true
  SyntheticWheelEvent: true
  SyntheticTouchEvent: true
  SyntheticUIEvent: true

rules:
  # Possible Errors <http://eslint.org/docs/rules/#possible-errors>
  # babel removes them for older browsers, we should do a codemod
  comma-dangle: [1, always-multiline]
  # equivalent to jshint boss
  no-cond-assign: 0
  # equivalent to jshint devel
  no-console: 0
  # prohibits things like `while (true)`
  no-constant-condition: 0
  # we need to be able to match these
  no-control-regex: 0
  # equivalent to jshint debug
  no-debugger: 2
  # equivalent to jshint W004
  no-dupe-args: 2
  # syntax error in strict mode, almost certainly unintended in any case
  no-dupe-keys: 2
  # almost certainly a bug
  no-duplicate-case: 1
  # almost certainly a bug
  no-empty-character-class: 1
  # would warn on uncommented empty `catch (ex) {}` blocks
  no-empty: 0
  # can cause subtle bugs in IE 8, and we shouldn't do this anyways
  no-ex-assign: 1
  # we shouldn't do this anyways
  no-extra-boolean-cast: 1
  # parens may be used to improve clarity, equivalent to jshint W068
  no-extra-parens: [1, functions]
  # equivalent to jshint W032
  no-extra-semi: 1
  # a function delaration shouldn't be rewritable
  no-func-assign: 2
  # babel and es6 allow block-scoped functions
  no-inner-declarations: 0
  # will cause a runtime error
  no-invalid-regexp: 1
  # disallow non-space or tab whitespace characters
  no-irregular-whitespace: 1
  # write `if (!(a in b))`, not `if (!a in b)`, equivalent to jshint W007
  no-negated-in-lhs: 2
  # will cause a runtime error
  no-obj-calls: 2
  # improves legibility
  no-regex-spaces: 1
  # we target es6!
  no-reserved-keys: 0
  # equivalent to jshint elision
  no-sparse-arrays: 2
  # equivalent to jshint W027
  no-unreachable: 2
  # equivalent to jshint use-isnan
  use-isnan: 2
  # probably too noisy ATM
  valid-jsdoc: 0
  # equivalent to jshint notypeof
  valid-typeof: 2
  # we already require semicolons
  no-unexpected-multiline: 0
  jsx-quotes: [2, prefer-double]
  no-dupe-class-members: 2
  no-restricted-syntax: [2, WithStatement]

  # Best Practices <http://eslint.org/docs/rules/#best-practices>
  # probably a bug, we shouldn't actually even use this yet, because of IE8
  accessor-pairs: 0
  # probably too noisy ATM
  block-scoped-var: 0
  # cyclomatic complexity, we're too far gone
  complexity: 0
  # require return statements to either always or never specify values
  consistent-return: 2
  # style guide: Always use brackets, even when optional.
  curly: [2, all]
  # we don't do this/care about this
  default-case: 0
  # disabled in favor of our temporary fork
  dot-notation: 2
  # we don't do this/care about this, but probably should eventually
  dot-location: [2, property]
  # disabled as it's too noisy ATM
  eqeqeq: [2, allow-null]
  # we don't do this/care about this, equivalent to jshint forin
  guard-for-in: 0
  # we have too many internal examples/tools using this
  no-alert: 0
  # incompatible with use strict equivalent to jshint noarg
  no-caller: 2
  # we don't do this/care about this
  no-div-regex: 0
  # we don't do this/care about this
  no-else-return: 0
  # see eqeqeq: we explicitly allow this, equivalent to jshint eqnull
  no-eq-null: 0
  # equivalent to jshint evil
  no-eval: 2
  # should only be triggered on polyfills, which we can fix case-by-case
  no-extend-native: 1
  # might be a sign of a bug
  no-extra-bind: 1
  # equivalent to jshint W089
  no-fallthrough: 1
  # equivalent to jshint W008
  no-floating-decimal: 2
  # implicit coercion is often idiomatic
  no-implicit-coercion: 0
  # equivalent to jshint evil/W066
  no-implied-eval: 2
  # will likely create more signal than noise
  no-invalid-this: 0
  # babel should handle this fine
  no-iterator: 0
  # don't use labels
  no-labels: 2
  # lone blocks create no scope, will ignore blocks with let/const
  no-lone-blocks: 1
  # equivalent to jshint loopfunc
  no-loop-func: 0
  # we may use this for alignment in some places
  no-multi-spaces: 1
  # equivalent to jshint multistr, consider using es6 template strings
  no-multi-str: 2
  # equivalent to jshint W020, similar to no-extend-native
  no-native-reassign: [2, {exceptions: [Map, Set]}]
  # equivalent to jshint evil/W054
  no-new-func: 2
  # don't use constructors for side-effects, equivalent to jshint nonew
  no-new: 1
  # deprecated in ES5, but we still use it in some places
  no-octal-escape: 1
  # deprecated in ES5, may cause unexpected behavior
  no-octal: 1
  # treats function parameters as constants, probably too noisy ATM
  no-param-reassign: 0
  # only relevant to node code
  no-process-env: 0
  # deprecated in ES3.1, equivalent to jshint proto
  no-proto: 2
  # jshint doesn't catch this, but this is inexcusable
  no-redeclare: 2
  # equivalent to jshint boss
  no-return-assign: 0
  # equivalent to jshint scripturl
  no-script-url: 2
  # not in jshint, but is in jslint, and is almost certainly a mistake
  no-self-compare: 1
  # there are very limited valid use-cases for this
  no-sequences: 1
  # we're already pretty good about this, and it hides stack traces
  no-throw-literal: 1
  # breaks on `foo && foo.bar()` expression statements, which are common
  no-unused-expressions: 2
  # disallow unnecessary .call() and .apply()
  no-useless-call: 1
  # this has valid use-cases, eg. to circumvent no-unused-expressions
  no-void: 0
  # this journey is 1% finished (allow TODO comments)
  no-warning-comments: 0
  # equivalent to jshint withstmt
  no-with: 0
  # require radix argument in parseInt, we do this in most places already
  radix: 1
  # we don't do this/care about this
  vars-on-top: 0
  # equivalent to jshint immed
  wrap-iife: 0
  # probably too noisy ATM
  yoda: 0

  # Strict Mode <http://eslint.org/docs/rules/#strict-mode>
  # jshint wasn't checking this, and the compiler should add this anyways
  strict: [1, global]

  # Variables <http://eslint.org/docs/rules/#variables>
  # we don't do this/care about this
  init-declarations: 0
  # equivalent to jshint W002, catches an IE8 bug
  no-catch-shadow: 2
  # equivalent to jshint W051, is a strict mode violation
  no-delete-var: 2
  # we should avoid labels anyways
  no-label-var: 1
  # redefining undefined, NaN, Infinity, arguments, and eval is bad, mkay?
  no-shadow-restricted-names: 1
  # a definite code-smell, but probably too noisy
  no-shadow: 2
  # it's nice to be explicit sometimes: `var foo = undefined;`
  no-undef-init: 0
  # equivalent to jshint undef, turned into an error in getConfig
  # NOTE: This diverges from internal - just turned into an error here since we
  # almost always do that anyway.
  no-undef: 2
  # using undefined is safe because we enforce no-shadow-restricted-names
  no-undefined: 0
  # equivalent to jshint unused
  no-unused-vars: [2, {args: none}]
  # too noisy
  no-use-before-define: 0

  # Node.js <http://eslint.org/docs/rules/#nodejs>
  # TODO: turn some of these on in places where we lint node code
  callback-return: 0
  handle-callback-err: 0
  no-mixed-requires: 0
  no-new-require: 0
  no-path-concat: 0
  no-process-exit: 0
  no-restricted-modules: 0
  no-sync: 0

  # Stylistic Issues <http://eslint.org/docs/rules/#stylistic-issues>
  # See also: https://our.intern.facebook.com/intern/dex/style-guide/
  array-bracket-spacing: 1
  brace-style: [1, 1tbs]
  # too noisy at the moment, and jshint didn't check it
  camelcase: [0, {properties: always}]
  comma-spacing: [1, {before: false, after: true}]
  # jshint had laxcomma, but that was against our style guide
  comma-style: [1, last]
  computed-property-spacing: [1, never]
  # we may use more contextually relevant names for this than self
  consistent-this: [0, self]
  # should be handled by a generic TXT linter instead
  eol-last: 1
  func-names: 0
  # too noisy ATM
  func-style: [0, declaration]
  # we weren't enforcing this with jshint, so erroring would be too noisy
  indent: [1, 4, {SwitchCase: 1}]
  # we may use extra spaces for alignment
  key-spacing: [0, {beforeColon: false, afterColon: true}]
  lines-around-comment: 0
  # should be handled by a generic TXT linter instead
  linebreak-style: [0, unix]
  max-nested-callbacks: 0
  # https://facebook.com/groups/995898333776940/1027358627297577
  new-cap: 0
  # equivalent to jshint W058
  new-parens: 2
  newline-after-var: 0
  # equivalent to FacebookWebJSLintLinter's checkPhpStyleArray
  no-array-constructor: 2
  no-continue: 0
  no-inline-comments: 0
  # doesn't play well with `if (__DEV__) {}`
  no-lonely-if: 0
  # stopgap, irrelevant if we can eventually turn `indent` on to error
  no-mixed-spaces-and-tabs: 2
  # we do this a bunch of places, and it's less bad with proper indentation
  no-nested-ternary: 0
  # similar to FacebookWebJSLintLinter's checkPhpStyleArray
  no-new-object: 1
  no-spaced-func: 1
  no-ternary: 0
  # should be handled by a generic TXT linter instead
  no-trailing-spaces: 0
  # we use this for private/protected identifiers
  no-underscore-dangle: 0
  # disallow `var isYes = answer === 1 ? true : false;`
  no-unneeded-ternary: 1
  # too noisy ATM
  object-curly-spacing: 0
  # makes indentation warnings clearer
  one-var: [1, {initialized: never}]
  # prefer `x += 4` over `x = x + 4`
  operator-assignment: [1, always]
  # equivalent to jshint laxbreak
  operator-linebreak: 0
  padded-blocks: 0
  # probably too noisy on pre-ES5 code
  quote-props: [0, as-needed]
  quotes: [1, single, {"allowTemplateLiterals": true}]
  semi-spacing: [1, {before: false, after: true}]
  # equivalent to jshint asi/W032
  semi: [1, always]
  sort-vars: 0
  # require `if () {` instead of `if (){`
  space-before-blocks: 2
  # require `function foo()` instead of `function foo ()`
  space-before-function-paren: [1, {anonymous: never, named: never}]
  space-in-parens: [1, never]
  space-infix-ops: 0
  # Currently broken: https://github.com/eslint/eslint/issues/2764
  space-unary-ops: [0, {words: true, nonwords: false}]
  # TODO: Figure out a way to do this that doesn't break typechecks
  # or wait for https://github.com/eslint/eslint/issues/2897
  spaced-comment: [0, always, {exceptions: [jshint, jslint, eslint, global]}]
  wrap-regex: 0
  # require `return -a` instead of `return-a` and `if ()` instead of `if()`
  keyword-spacing: 1



  # ECMAScript 6 <http://eslint.org/docs/rules/#ecmascript-6>
  # TODO: our style guide says to always use parens, even w/ a single param
  arrow-parens: 0
  # tbgs finds *very few* places where we don't put spaces around =>
  arrow-spacing: [1, {before: true, after: true}]
  # violation of the ES6 spec, won't transform
  constructor-super: 2
  # https://github.com/babel/babel-eslint#known-issues
  generator-star-spacing: 0
  no-class-assign: 1
  # this is a runtime error
  no-const-assign: 2
  # violation of the ES6 spec, won't transform, `this` is part of the TDZ
  no-this-before-super: 2
  # we have way too much ES3 & ES5 code
  no-var: 0
  object-shorthand: 0
  # will only impact future ES6 code that'll use let
  prefer-const: 1
  prefer-spread: 0
  # we don't support/polyfill this yet
  prefer-reflect: 0
  # there are legitimate use-cases for an empty generator
  require-yield: 0

  # Legacy <http://eslint.org/docs/rules/#legacy>
  max-depth: 0
  # TODO: replace regexp linter with this, using {ignorePattern}
  max-len: 0
  max-params: 0
  max-statements: 0
  no-bitwise: 0
  no-plusplus: 0

  # JSX
  # Our transforms set this automatically
  react/display-name: 0
  react/jsx-boolean-value: [2, always]
  react/jsx-no-undef: 2
  # We don't care to do this
  react/jsx-sort-prop-types: 0
  react/jsx-sort-props: 0
  react/jsx-uses-react: 2
  react/jsx-uses-vars: 2
  # It's easier to test some things this way
  react/no-did-mount-set-state: 0
  react/no-did-update-set-state: 0
  # We define multiple components in test files
  react/no-multi-comp: 0
  react/no-unknown-property: 2
  # This isn't useful in our test code
  react/prop-types: 0
  # We're using react in global scope (via WebPack vendors.js)
  # react/react-in-jsx-scope: 2
  react/self-closing-comp: 2
  # We don't care to do this
  react/sort-comp: 0
  react/wrap-multilines: [2, {declaration: false, assignment: false}]