objectKeys
Like Object.keys() but with a better return type
Functionally identical to
Object.keys() except that the return type ain't just string but a typed array.import { assert, Equals } from "tsafe";
import { objectKeys } from "tsafe/objectKeys";
const obj = {
a: 1,
b: "ok",
c: null,
};
// v keys is an array of "a", "b", "c"
const keys = objectKeys({
a: 1,
b: 2,
c: 3,
});
assert<Equals<typeof keys, ("a" | "b" | "c")[]>>();
WARNING: Only use with object you have instantiated yourself. Some keys that are not in the type might be present on the object at runtime!
const o = { p: 33, k: "ok", r: false };
const x = objectKeys<{ p: number; k: string }>(o);
//x is of type ("p" | "k")[] but actually x === ["p", "k", "r"]
Last modified 8mo ago