v.nullish(v.string(), undefined) alternative

[akrynski-1]

I updated valibot and discovered that after #878 the following pattern does not convert null to undefined anymore.

const schema = v.nullish(v.string(), undefined);
const result = v.parse(schema, null);
console.log(result); // null

Types also reflect that change, what is recommended way of doing this conversion now?

[fabian-hiller]

Hey, sorry for producing a bug in your code. Here is a fix:

const schema = v.nullish(v.string(), () => undefined);
const result = v.parse(schema, null);
console.log(result); // undefined

Due to some TypeScript issues, undefined is now treated as having no default. The workaround is to pass a function that returns undefined.

[akrynski-1]

Thank you for a quick reply, fix you provided does work for me