How to defining Valibot schemas that agree with a TypeScript type?

[hungify]

Example from Zod

import { toZod } from 'tozod';

type Player = {
  name: string;
  age?: number | undefined;
  active: boolean | null;
};

export const Player: toZod<Player> = z.object({
  name: z.string(),
  age: z.number().optional(),
  active: z.boolean().nullable(),
});

How can I achieve that in Valibot?

[fabian-hiller]

You can use BaseSchema:

import * as v from 'valibot';

type Player = {
  name: string;
  age?: number | undefined;
  active: boolean | null;
};

export const Player = v.object({
  name: v.string(),
  age: v.optional(v.number()),
  active: v.nullable(v.boolean()),
}) satisfies v.BaseSchema<Player>;

[fabian-hiller]

Thank you. Now I get it. No, that does not work. This is the only way it would work, but it's way too complicated:

import * as v from 'valibot';

export const Player = v.object({
  name: v.string(),
  age: v.optional(v.number()),
  active: v.nullable(v.boolean()),
}) satisfies v.ObjectSchema<{
  name: v.StringSchema<string>;
  age: v.OptionalSchema<v.NumberSchema<number>, undefined>;
  active: v.NullableSchema<v.BooleanSchema<boolean>, undefined>;
}>;

[fabian-hiller]

Can you explain your use case to me? Why don't you use the schema as the source of true for validation and type?

[hungify2022]

Many thanks <3

I'm trying an integration type-safe API client with openapi-ts.
I want to ensure requests and responses are correct (another layer).

Your solution helped me create the correct schema easily.

[hungify2022]

I found another way to create a schema based on types.
It matches with v.BaseSchema<Player> without v.ObjectSchema<{...}>

https://sinclairzx81.github.io/typebox-workbench/

[fabian-hiller]

Yes, that's a cool website!