Broken overload in `z.record()`.

[colinhacks]

There's a bug in the overloads for z.record() that lets you to pass in an arbitrary schema as the key schema into z.record()...whoops.

const schema = z.record(z.object({ name: z.number() }), z.number());
// no TS errors

The expected behavior is that the first argument should conform to type KeySchema = ZodType<string | number | symbol, any, any>; but it currently doesn't.

In order to fix it I need to remove the "single argument" shorthand: z.record(z.number), which will land in Zod 4.

[LemonAppleMo]

Did you write it backwards?

const User = z.object({ name: z.string() });

const UserStore = z.record(z.string(), User);

[colinhacks]

I did not. The point is that this code should throw an error when I try to pass a ZodObject as the key, but it doesn't.

[LiamMartens]

@colinhacks looks like this could be fixed like this:

static create<Value extends ZodTypeAny, Params extends RawCreateParams>(
  valueType: Value,
  params?: Params extends ZodTypeAny ? never : Params
): ZodRecord<ZodString, Value>;

Not super ideal but it will complain about it will never if the 2nd param is a ZodTypeAny forcing TS to choose the other overload.

Though if you're removing the single arg variant this would be moot