tsc --build repo2

repo1/dist/a.d.ts(1,19): error TS2307: Cannot find module 'b' or its corresponding type declarations.

tsc --build repo1

success

Type declaration imports are not resolved correctly. They are resolved from the rules in repo2/tsconfig.json.

This means that if we create repo2/b.ts with this content:

import {T} from 'repo1';

export type {T};

This is the content for repo3.

tsc --build repo3

repo3/b.ts(1,9): error TS2303: Circular definition of import alias 'T'.

since repo1/a.d.ts imports 'b' (resolves to repo3/b.ts) -> imports repo1/a.d.ts -> ...

repo1/a.d.ts importing 'b' should resolve to repo1/b.d.ts and not repo3/b.ts

To show that this is an issue with d.ts file importing and no path/references, repo4 has no tsconfig and has a copy of repo1 inside its node_modules.