Re-exported type reported as unused with ignoreExportsUsedInFile

[haines]

Repro: https://stackblitz.com/edit/github-hqqlbk?file=component%2Findex.ts

We have a standard module template for our React components, so that every component (at least) exports its props and the component itself, like

// component.ts
export interface ComponentProps { ... }
export default function Component(props: ComponentProps) { ... }

This works fine with Knip even if nothing imports the props, as long as ignoreExportsUsedInFile is set to true.

However, it doesn't work on our wrapper components, where we re-export the props from an internal file

// index.ts
import { ComponentProps } from "./component";

export type { ComponentProps };
export default function Wrapper(props: ComponentProps) { ... }

I would have expected in this case that ComponentProps would not be reported as an unused export from index.ts because of ignoreExportsUsedInFile, but it was:

$ npm run knip

> @knip/[email protected] knip
> knip

Unused exports (1)
ComponentProps  unknown  component/index.ts:4:9

[webpro]

Thanks for the report, @haines. The issue is that the usage of ComponentProps refers to the import, not the export. But a strict re-export wouldn't be an import, and therefore no usage would be possible. So I've tried to come up with a fix.

[webpro]

🚀 This issue has been resolved in v5.12.2. See Release 5.12.2 for release notes.

Using Knip in a commercial project? Please consider sponsoring me.

[haines]

Awesome, thanks for fixing it so quickly! I've tried out 5.12.2 and it no longer reports these cases 🎉