Expect type go to optional to be unoptional...

[hpachy]

Bug Report

🔎 Search Terms

-Make some properties optional in a TypeScript type
-typescript pick optional

🕗 Version & Regression Information

currrent version : "typescript": "^5.1.6"
Don t know if that bug existed before, just got the issue right now

⏯ Playground Link

Bug on the typescript playground

💻 Code

Code inside the playground

🙁 Actual behavior

Even if I condition the type I still got an error raise by typescript which is Type 'string | undefined' is not assignable to type 'string'

🙂 Expected behavior

I expect type go to optional to be unoptional

[MartinJohns]

Duplicate of #42384 and many others.

It would be a fairly unsafe operation as well. fnTest could store a reference to the object to be used later, but meanwhile undefined could be assigned to the objects property.

[typescript-bot]

This issue has been marked as "Duplicate" and has seen no recent activity. It has been automatically closed for house-keeping purposes.