Intersections

An intersection represents a logical AND relationship. You can apply this concept to your schemas with intersect and partially by merging multiple object schemas into a new one. I recommend this approach for simple object schemas, and intersect for all other cases.

Intersect schema

The schema function intersect creates an AND relationship between any number of schemas that you pass as the first argument in the form of an array. To pass the validation, the validation of each schema passed must be successful. If this is the case, the schema merges the output of the individual schemas and returns the result. If the validation fails, the schema returns any issues that occurred.

import * as v from 'valibot';

// TypeScript
type Intersect = { foo: string } & { bar: number };

// Valibot
const IntersectSchema = v.intersect([
  v.object({ foo: v.string() }),
  v.object({ bar: v.number() }),
]);

Merge objects

Technically, there is a big difference between intersect and object merging. intersect is a schema function that executes the passed schemas during validation. In contrast, object merging is done during initialization to create a new object schema.

As a result, object merging usually has much better performance than intersect when validating unknown data. Also, subsequent object properties overwrite the previous ones. This is not the case with intersect, since the validation would fail if two properties with the same name are fundamentally different.

import * as v from 'valibot';

const ObjectSchema1 = v.object({ foo: v.string(), baz: v.number() });
const ObjectSchema2 = v.object({ bar: v.string(), baz: v.boolean() });

const MergedSchema = v.object({
  ...ObjectSchema1.entries,
  ...ObjectSchema2.entries,
}); // { foo: string; bar: string; baz: boolean }

In the previous code example, the baz property of the first object schema is overwritten by the baz property of the second object schema.