import/named error for JSDoc typedef

[matt-tingen]

In TypeScript with the allowJs flag, types defined in a JSDoc can be imported in .ts files, but the import/named rule is not aware of the implicit export from the JSDoc and thus marks the import as invalid.

Example:

// Foo.js
/** @typedef {keyof Foo} FooKey */
class Foo { /* ... */ }
export default Foo;

// Bar.ts
import Foo, { FooKey } from './Foo';

This yields error FooKey not found in './Foo' import/named.

It may be possible to use tsdoc to extract the type definitions.

Related: #1282

[ljharb]

oof, this seems very complex. i'd want to enable this by a setting only, not by default.

[matt-tingen]

Absolutely. Honestly, I'm not totally sure how worth it it would be to implement. Personally, I just disabled import/named for .tsx? files in our project since TS performs the check, anyway.

[JounQin]

You can use

import Foo, { type FooKey } from './Foo';

It won't error now.