Cannot use `override` keyword to override methods of `Object` without explicitly extending `Object`

Bug Report

🔎 Search Terms

override, TS4112

🕗 Version & Regression Information

It happens in 4.4.2 and has been there since the introduction of override keyword (#39669).

⏯ Playground Link

https://www.typescriptlang.org/play?#code/MYGwhgzhAECC0G8BQ1oHsBuBTATjglgCZbQAuaAyqQQHYDmAFAJSKo5akCuON0A5ADM0aPgG5oAXyQSgA

💻 Code

class A {
  override toString() { return 'foo'; }
}

🙁 Actual behavior

TS4112: This member cannot have an 'override' modifier because its containing class 'A' does not extend another class.

🙂 Expected behavior

It should be allowed, since the method overrides Object.prototype.toString.

Per ECMAScript spec §15.7.12.7, a class without an explicit extends clause would be implicitly inheriting from Object. Therefore, such classes should be allowed to explicitly override methods declared in Object.

Riproduci il caso nel TypeScript Playground collegato ed esamina la dichiarazione di Object in lib/lib.es5.d.ts. Traccia il comportamento del controllo di override per una classe senza una clausola extends esplicita. Il lavoro è completato quando l'esempio viene accettato, mentre i controlli di override rimangono applicati per gli altri casi.