Proposal: SetKeyRequired with key required, but allow undefined value

[Clindbergh]

type a = { a?: number, b: number | undefined};

type b = SetRequired<a, 'a' | 'b'>;

I would have expected the type b to be: (1)

{ a: number, b: number | undefined }

however the type seems to be

{ a: number, b: number }

Is there a way to enforce the presence of the key but not require the value to be defined (like (1))?

This can be manually achieved with this type definition:

{ a: b['a'], b: b['b'] }

But this is a bit more cumbersome.

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[sindresorhus]

Do you have "exactOptionalPropertyTypes": true, in your tsconfig?

[Clindbergh]

Thanks a lot @sindresorhus for drawing my attention on exactOptionalPropertyTypes which was unknown to me.
_{For anyone who also thought strict is the strictest you can get, I found this article quite helpful.}

At the moment I am unable to reproduce the issue, I may have been working with an older typescript version. It seems to work as expected. exactOptionalPropertyTypes should not be required. Closing it for now.