Type created with union loses its part after Omit

[everdimension]

Bug Report

🔎 Search Terms

omit loses type info union generic

🕗 Version & Regression Information

Version: 4.2.4

• I was unable to test this on prior versions because omg it's exhausting

⏯ Playground Link

Playground link with relevant code

💻 Code

interface Base<T> {
  x: T,
  y: number;
}

type Additional = { a: number } | { b: string };
type Specific<T> = Base<T> & Additional;

type Final<T> = Omit<Specific<T>, 'y'>

const x: Final<number> = { x: 23 }; // must warn about missing 'a' | 'b', but doesn't

🙁 Actual behavior

Final type doesn't have properties of type Additional

🙂 Expected behavior

Final type must properties of type Additional

[MartinJohns]

Duplicate of #39556.

[RyanCavanaugh]

omg it's exhausting

No one is forcing you to fill out this report; please just refrain from doing so if you aren't able to complete the steps asked of you. We put those steps in there for a reason and I assure you someone else will log the issue if it's legitimate. (That said, lol, I feel you)

[everdimension]

@RyanCavanaugh this wasn't meant as an attack. Just the first thing I felt when reading the template. Also the template comment asked to keep one line.
Thanks for understanding! 🙂