In my source interface I have:

interface ContrivedInterface {
  problematicNumber?: number | null;
}

I would write it in zod as follows:

const contrivedZod: toZod<ContrivedInterface> = z.object({
  problematicNumber: z.number().nullable().optional()
})

Problem is, the type of problematicNumber from z.infer is z.ZodOptional<z.ZodNullable<z.ZodNumber>>, whereas the type of problematicNumber generated by toZod<ContrivedInterface> is ZodOptional<never> | ZodOptional<ZodNumber> causing a type mismatch.

The exact ts error:

Type '{ problematicNumber: z.ZodOptional<z.ZodNullable<z.ZodNumber>>; }' is not assignable to type '{ problematicNumber: ZodOptional<never> | ZodOptional<ZodNumber>; }'.

My usecase is, I want to be able to send null from client to server as an indicator that I want problematicNumber to be unset on backend because undefined is not a valid JSON value so I can't use it in my payload. So undefined represents a lack of value whereas null represents intentional removal of value.