Optional object index signatures do not work.

[Bas950]

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🧩 Context

• ArkType version:
• TypeScript version (5.1+):
• Other context you think may be relevant (JS flavor, OS, etc.):

🧑‍💻 Repro

Playground Link: https://arktype.io/playground?code=import%2520%257B%2520scope%2520%257D%2520from%2520%2522arktype%2522%250A%250Aconst%2520Thing%2520%253D%2520scope%28%257B%250A%2509Locales%253A%2520%27%2522en%2522%2520%257C%2520%2522nl%2522%2520%257C%2520%2522de%2522%27%252C%250A%2509Option%253A%2520%257B%250A%2520%2520%2520%2520%2520%2520%2520%2520%27%255BLocales%255D%253F%27%253A%2520%27string%27%252C%250A%2520%2520%2520%2520%257D%252C%250A%257D%29.export%28%29%250A%250Aconst%2520out%2520%253D%2520Thing.Option%28%257B%250A%2520%2520%2520%2520en%253A%2520%2522test%2522%250A%257D%29%250A

import { scope } from "arktype"

const Thing = scope({
	Locales: '"en" | "nl" | "de"',
	Option: {
        '[Locales]?': 'string',
    },
}).export()

const out = Thing.Option({
    en: "test"
})

Out currently resolves to:

const out: ArkErrors | {
    '[Locales]'?: string;
}

Instead of:

const out: ArkErrors | {
    en?: string;
    nl?: string;
    de?: string;
}

---

Also I noticed that if you have a pipe in the index signature it also breaks (playground link)

[Bas950]

Side question: when this is fixed, is there also a way to make at least 1 property required?

Or just narrow it and see if the objects has keys?

[Sam-C137]

Side question: when this is fixed, is there also a way to make at least 1 property required?

Or just narrow it and see if the objects has keys?

Check out #1525