Proxy ownKeys trap accepts a primitive result

[d01c2]

Reproduction

Reflect.ownKeys(new Proxy({}, { ownKeys: () => 0 }));

Expected

A TypeError is thrown.

V8 (15.3.27):

d8> Reflect.ownKeys(new Proxy({}, { ownKeys: () => 0 }));
TypeError: CreateListFromArrayLike called on non-object

Actual (QuickJS-ng)

QuickJS-ng treats the primitive result as an empty key list:

qjs > Reflect.ownKeys(new Proxy({}, { ownKeys: () => 0 }));
[]

Spec

The Proxy [[OwnPropertyKeys]] method passes the result of the ownKeys trap to CreateListFromArrayLike.

CreateListFromArrayLike must throw a TypeError when its argument is not an Object. Since 0 is a Number primitive, the call must throw instead of returning an empty array.

Versions

• QuickJS-ng: 0.16.0
• V8: 15.3.27