@thorn0 All done. You may want make some adjustments?

I thought we had tests for union and intersection types shared between Flow and TS, but turns out we didn't. If we add such tests, what directory should we put them in?

Maybe js, unlike other languages, I moved original typescript-* in typescript, kind of typescript-only in typescript, flow-only in flow , for example js don't has interface, I don't know where to put it, I moved to js. Do you have good idea?

I wish I had. All possible solutions seem to be non-obvious for contributors.

Let's think this way, image we don't have inline-comment tests, you want test it in scss now, you should put it in scss/, and I'll say, please add tests in less/ too, or please verify with less parser too. Someday, css support this too, we can add separate tests in css/, or add css parser to tests in scss/.

So union and intersection types, you can

• put in typescript/ and verify with flow/babel-flow
• put in flow/ and verify with typescript/babel-ts
• put duplicated tests in both typescript/ and flow/

I think better in this way.

To enforce this way, I'll update this check https://github.com/prettier/prettier/blob/master/tests_config/utils/check-parsers.js#L15

To something like:

WDYT?