Collapse nested keys in TypeScript?

Question

Say I have two types in TypeScript:

interface Foo {
  bar: string;
}

interface Baz {
  foo: Foo;
}

Is there a way in TypeScript to flatten Baz (e.g. type FlatBaz = Flat<Baz>), such that the signature looks something like this?

interface FlatBaz {
  "foo.bar": string;
}

I'd be interested to know what you're trying to achieve. because your `FlatBaz` type looks like it would be the structure of a type returned from some function — Damian Green, May 04 '20 at 19:58
Possible duplicate of [Typescript: deep keyof of a nested object](https://stackoverflow.com/questions/58434389/typescript-deep-keyof-of-a-nested-object) — jcalz, May 04 '20 at 20:08
@DamianGreen yes - it would be returned from a function. I'm mapping objects to/from query parameters and would like to more strongly type the behavior. — Craig Smitham, May 04 '20 at 20:27

score 1 · Accepted Answer · answered May 04 '20 at 20:39

1

No. Currently there is no way to concat string literal types with Typescript:

answered May 04 '20 at 20:39

Lodewijk Bogaards

score 0 · Answer 2 · answered May 04 '20 at 19:57

0

AFAIK, there is no such a thing.

answered May 04 '20 at 19:57

HTN

2 Answers2