getDefaults sould return [] instead of undefined for arrays

[notramo]

The getDefaults function returns undefined as a default value for array(), but it's not ergonomic. I find myself always doing one of the following:

• Add unnecessary complication to code that works with the input, to handle undefined, e.g. instead of doing a simple .push(), I have to add an undefined check or a nullish coalescing operator.
• Add an optional() with default value []

I recommend to set the out-of-the-box default value to [], as it covers the majority of use cases, and if undefined default is needed, there's optional() and undefinedable().

import { getDefaults, object, array, string } from 'valibot';

const mySchema = object({
  myArray: array(string()),
});

console.debug(getDefaults(mySchema));

outputs:

{
  myArray: undefined,
}

better output would be:

{
  myArray: [],
}

[fabian-hiller]

Currently, getDefaults only supports object and tuple schemas. Feel free to share your use case so we can investigate whether we should change the current implementation.

Here is a workaround that might work for you in the meantime. Otherwise you can copy the source code of getDefaults and modify it to your needs.

import * as v from 'valibot';

const Schema = v.object({
  array: v.optional(v.array(v.string()), []),
});

const defaults = v.getDefaults(Schema);