Is there a Zod method that will mutate the key?

Question

Given this schema, mutate the key "user_id" to "user":

const schema = z.object({
    user_id: z.string() // <--- some method here to mutate the key,
});

let input = { user_id: 1234qwer5678 }

let output = schema.parse( input )

console.log(output) // returns { id: 1234qwer1234 }

Answer 1

You can use transform to modify the data after it has been parsed by the underlying schema. So for example:

const schema = z.object({
  user_id: z.string(),
}).transform(({ user_id, ...rest }) => ({
  user: user_id,
  ...rest
});

This will accept an object with user_id as the field but when parsing will return the value under the user key instead.