import type { X as Y } from "@package"; - Import alias doesn't get build properly and get lost

[sshmaxime]

I'm expecting tsup & dts to not change my alias declarations name like import type { X as Y } from "@package"; but it seems like it does indeed remove them. Leading to problem in build types. Is this expected ?

Explanations:
Codesandbox

1. I'm declaring my types namespace in src/test.ts.
   Info: I'm importing my external package like so import type { PartialDeep as PartialDeepPrimitive } from "type-fest";

2. It compiles in dist/esm/test.d.ts.
   Info: The import get transformed to import { PartialDeep } from 'type-fest'; and thus exporting that way in my namespace: type PartialDeep<T> = PartialDeep<T>; which is a problem I'm assuming - it seems like it produces a sort of type loop.

3. When using the builded files in src/index.ts, types.PartialDeep logically resolves to any.

Can someone explain why it does this and if I can fix this quickly with a param or if this is just an actual issue ?

Thanks :)

Upvote & Fund

• We're using Polar.sh so you can upvote and help fund this issue.
• We receive the funding once the issue is completed & confirmed by you.
• Thank you in advance for helping prioritize & fund our backlog.