Circular flow type definitions trigger no-use-before-define

[qm3ster]

Brought here from eslint/eslint#8703, by @soda0289 request:
When using core rule no-use-before-define, default for example in standard, it is applied to type definitions.
This could be a good thing, but the current implementation gives an unavoidable error on circular definitions:

/* @flow */
type File = {chunks: Array<Chunk>}
type Chunk = {file: File}

produces

.../src/commands.js
  2:21  error  'File' was used before it was defined  no-use-before-define

✖ 1 problem (1 error, 0 warnings)

OR

/* @flow */
type Chunk = {file: File}
type File = {chunks: Array<Chunk>}

produces

.../src/commands.js
  2:28  error  'Chunk' was used before it was defined  no-use-before-define

✖ 1 problem (1 error, 0 warnings)

respectively.

Currently, disabling no-use-before-define in the files that have flow enabled (all for me) is a fix when actual flow is checked, since that catches undefined.
However, it is still probably a bug, since:

// This is an actual error
const a = {b}
const b = {a}
// While this works and is often necessary
type A = {b:B}
type B = {a:A}

[brendanzab]

I worked around this by disabling the check inline:

/* eslint-disable no-use-before-define */

export type GetState = () => State;
export type ThunkAction = (dispatch: Dispatch, getState: GetState) => any;
export type PromiseAction = Promise<Action>;
export type Dispatch = (action: Action | ThunkAction | PromiseAction) => any;

/* eslint-enable no-use-before-define */

[hzoo]

Had to revert this because this was causing many issues in other rules due to the AST change in #697, https://github.com/babel/babel-eslint/releases/tag/v10.0.1

[techieshark]

Tip for folks putting types in a types/ (etc) specific directory, you might add an eslint config file to disable the rule for that directory:

// .eslintrc.js
module.exports = {
  'rules': {
    'no-use-before-define': 'off',
  },
};

[linonetwo]

Maybe add another option in config to allow type be ignored by this rule? Both flow and typescript.

[kaicataldo]

Thank you for the issue. Now that @babel/eslint-parser has been released, we are making this repository read-only. If this is a change you would still like to advocate for, please reopen this in the babel/babel monorepo.