Typescript - Programmatic generation of union types from exports

Question

So, I have a file structure like this:

|---- foo.ts
|---- bar.ts
|- index.ts

Both foo.ts and bar.ts export a Data interface. What I'd want is to basically create a union type out of the 2 Data interfaces exported from foo and bar. Ideally, this should also be future proof. I.e. if I add a third file at the same level of foo and bar, that file will also export a Data interface and that should be included in the union type too.

I was wondering if there was a way of doing this without performing type generation from a JSON schema or something at "compile" time and the programmatic creation of the union type itself from this.