Return type of .default() should not be nullable

[pokey]

If I call .default(), why does it make the output type nullable? If I have provided a default value, shouldn't the output never be null?

[ealmansi]

can't reproduce on the latest version; adding default does not make the output type nullable:

// v3.19.1
import { z } from "zod";

const schema = z.object({
  x: z.string().default("str"),
});

export type Schema = z.infer<typeof schema>;
// type Schema = {
//   x: string;
// }

[scotttrinh]

It's possible that this is a misunderstanding as well: default works like JavaScript default assignment in destructuring: it replaces undefined with the default value. So if you input schema is nullable, adding a default does not make it non-nullable, it just allows the input to be optional (T | undefined) and makes the output non-optional (T).

Closing since this is working as intended, but feel free to post follow-up questions!