2.1 removes quotes from numeric keys in flow types

[TrySound]

Prettier 2.1.0
https://prettier.io/playground/#N4Igxg9gdgLgprEAuEATOYA2BDATnAAhgE8AHQgYQkwlwIF4DgAfAHSgIIHIBWABi5ICAZxi4AllADmAGnacuARj4ChoidLkduAJhWCRYybPncAzPrVHNprgBZLhjSajMAviBkgIpGOOjCyKB4uBAA7gAKeAiBKNiYYdjEgV4ARrjYYADWcDAAyqSZxshiAK5wXnAAtqlwqOioADLY0qXYUnAAYrRV2DB+0sgg2KUwEJ4gABYwVZgA6pPi8MKFYHB5MUviAG5LxENgwikgksJwuDARGVK9yABm8WdeAFbCAB4AQhnZuXnYVXBGpI4PdHhUQK83nljJg4ABFUoQeCgzBPECFXBnXBDVLYWqYCakDQwObiVAwSbIAAcfC8RIgZzmGVIQyJcCx2xBXgAjoj4FcfLFhsIALRQOB1OoTfC88T4K7tW5IB6o8FnKriEq4cpeYQw+F8kHKsFeGB40nkylIHSmjLiTDGKhVJUgdk8CalM4AFTxsRVaO25QAklB0LA8mAJL4AIKhvIkWEos5uNxAA

# Options (if any):
--single-quote

Flow does not allow numeric keys without quotes in types. In objects it's not allowed as well though this is something I could deal with. With types it's a bug.

Input:

declare type Color = {|
  '50': string,
  '100': string,
  '200': string,
  '300': string,
  '400': string,
|}

Output:

declare type Color = {|
  50: string,
  100: string,
  200: string,
  300: string,
  400: string,
|};

Expected behavior:

declare type Color = {|
  '50': string,
  '100': string,
  '200': string,
  '300': string,
  '400': string,
|}

[fisker]

flow or babel-flow parser is recommended, they don't remove quotes.

[TrySound]

This looks like a solution. Thanks.

[fisker]

@TrySound A unrelated question, do you use flow with @flow comment? I proposed to drop flow support from babel parser in #8204, and @thorn0 suggest that auto switch to babel-flow if @flow found(or maybe .flow.js in filename too), if we do that you would be able to use babel without breaking your code.

[TrySound]

Yes, I always use flow annotation.

[fisker]

Thank you!