z.pick() with z.partial() ignores z.pick() for zod mini.

[JoshuaKirby88]

import * as z from "@zod/mini"

const userSchema = z.interface({ id: z.number(), email: z.email(), name: z.string() })

type UserSchema = z.infer<typeof userSchema>
// UserSchema = {
//     id: number;
//     email: string;
//     name: string;
// }

const pickedUserSchema = z.pick(userSchema, { id: true, email: true })

type PickedUserSchema = z.infer<typeof pickedUserSchema>
// PickedUserSchema = {
//     id: number;
//     email: string;
// }

const partialPickedUserSchema = z.partial(pickedUserSchema, { id: true })

type PartialPickedUserSchema = z.infer<typeof partialPickedUserSchema>
// PartialPickedUserSchema = {
//     id?: number | undefined;
//     email: string;
// }

const wrongSchema = z.partial(z.pick(userSchema, { id: true, email: true }), { id: true })

type WrongSchema = z.infer<typeof wrongSchema>
// WrongSchema = {
//     id?: number | undefined;
//     email: string;
//     name: string;
// }

partialPickedUserSchema and wrongSchema should be the same, but they are different. When defining the pickedUserSchema inside z.partial(), it ignores z.pick(), and is adding back the name field.

[JoshuaKirby88]

Solution for now is to add ".clone()":

z.partial(z.pick(userSchema, { id: true, email: true }).clone(), { id: true })

[colinhacks]

Smart fix with .clone().

This is an interesting limitation of TS inference. I've found a workaround so .clone() shouldn't be necessary in latest betas.

[JoshuaKirby88]

🙏