🔎 Search Terms

object spread, object rest, object spreading

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about object spreading

⏯ Playground Link

https://www.typescriptlang.org/play?ts=5.2.2#code/CYUwxgNghgTiAEYD2A7AzgF0QLngb3gG0BrEAT10xgEsUBzAXVxQFcBbAIxBngF8BYAFDJ0WKLgIlylDDXpN4VWnT7wAvPiEBIcfADkegDTaAdGbBDeQA

💻 Code

declare const c: { [key: string]: number }
const a: { [key: string]: string } = {
	a: '',
	...c
}

🙁 Actual behavior

It allows numbers to be in the object, when they shouldn't be allowed.

🙂 Expected behavior

It shouldn't allow numbers.

Additional information about the issue

Because c has non-literal keys, in this case string, which could be any string, it doesn't care what's in it.