No error when using spead operator on an interal's properties

[jgresty]

Bug Report

🔎 Search Terms

spread built-in internal

🕗 Version & Regression Information

• This is the behaviour in every version I tried, and I reviewed the FAQ for entries about type system behaviour

⏯ Playground Link

Playground link with relevant code

💻 Code

const a = (buff: { byteLength: number }) => console.log(buff.byteLength)
const buff = new ArrayBuffer(123)
a(buff) // Fine
a({...buff}) // Prints undefined, expected error

🙁 Actual behavior

Properties are not copied with the spread operator but the typing of the new object asserts they are present.

🙂 Expected behavior

The type of an object constructed with the spread operator to not include properties that were not copied to it.

[RyanCavanaugh]

Duplicate #9726

[typescript-bot]

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