Spread operator with computed property is not being checked

[val-o]

🔎 Search Terms

spread, computed property, unsoundness

🕗 Version & Regression Information

For any TS version

⏯ Playground Link

LINK

💻 Code

type MyKey = 'key-1' | 'key-2'

interface Obj {
    a: number
}

type MyRecord = Record<MyKey, Obj>

declare const someRecord: MyRecord
declare const key: MyKey

const overriden: MyRecord = {
    ...someRecord,
    [key]: 'anything is oke here, why?'
}

🙁 Actual behavior

No type check errors

🙂 Expected behavior

On line 14, we assign string ''anything is oke here, why?'' as a value of a MyRecord type, whose value are typed as interface with one number property. This should lead to error since in runtime the record no longer will have values of type Obj

Additional information about the issue

No response

[RyanCavanaugh]

Duplicate e.g. #13498, #49372, #50185 - there isn't a good type system representation of what [key]: value does when key is a union, so it's not a straightforward matter to check that it isn't doing something illegal