Zod 2 beta 5: parse() adds optional fields with 'undefined' as a value

Hi @vriad,

I’ve upgraded to Zod 2 beta and it works cool.

The first bug I’ve met now, is that if you send an object without certain optional fields, .parse() adds them with undefined value.

For instance, my schema looks like that (simplified):

export const SNamedEntity = z.object({
  _id: string().refine(validateUUID),
  name: z.string().max(100),
  createdAt: string().refine(validateDateString).optional(),
  updatedAt: string().refine(validateDateString).optional(),
  isActive: boolean().optional(),
});

And the object I send to it has only _id and name. However, when I set a breakpoint after I .parse() this object with the with the above schema, I see that all of the optional fields are present there now:

{ 
  _id: '5f6418f13b179e3da326a1aa',
  name: "John Doe",
  createdAt: undefined,
  updatedAt: undefined,
  isActive: undefined,
}

It freaks out Mongo, it thinks that I’m trying to overwrite its internal createdAt field with undefined and throws me an error.

Interestingly, if I send a valid date in createdAt field, mongo is totally allright with that (it ignores it as it should). Only undefined trips it 😃

[colinhacks]

@grreeenn @sylvanaar @o-alexandrov this is fixed in zod@2.0.0-beta.9

[sylvanaar]

https://github.com/vriad/zod/blob/a014ff6d041801e13021bc21fd359b3e20318ffd/src/parser.ts#L369

Probably should be

        const keyValidator = dataKeys.includes(key)