Bug Report

🔎 Search Terms

bug extends number bigint

🕗 Version & Regression Information

• This was reported in support generic type when checking implicit conversion of symbol to string #44578 and occurs in playground on v4.74 and v4.8.0-beta

⏯ Playground Link

Playground link with relevant code

Playground link with original code from #44578

💻 Code

type numberOrBigint = number | bigint;

function getKey(key: numberOrBigint) {
    // @ts-expect-error ✔
    +key;
    // @ts-expect-error ✔
    0 + key;
}

function getKey2<S extends numberOrBigint>(key: S) {
    // @ts-expect-error ❌ should error, but the compiler does not
    +key;
    // @ts-expect-error ✔
    0 + key;
}

🙁 Actual behavior

+key is not an error in getKey2.

🙂 Expected behavior

It should be an error to be consistent with getKey, as S could be numberOrBigint instead of a more specific type.