Zod Extended

Do more with your Zod schemas.

npm add zod-x

API

zx(schema)

• .resolve(...)

Resolve

Resolve/computed fields according to a parent object.

Description

The resolve functionality aims to make "field-resolution" or "computed fields" simple in Zod. Computed or resolved fields enable deriving new fields based on existing object fields. A common use case for computed fields is collecting relation data.

⚠️ This requires using .parseAsync() to parse schema

Usage

First define a "resolveable" field on an object.

// Schema of resolved type
const Photo = z.object({
	src: z.string(),
	width: z.number(),
	height: z.number()
})

const User = z.object({
	id: z.string(),
	photoId; z.string(),

	// Add a resolved field
	Photo: zx(Photo).resolve(async (parent) => {
		return db.photo.findUnique({
			where: { id: parent.photoId }
		})
	})
})

By default these resolvers won't ever be run, and the computed fields never populated, until you wrap a schema in the .resolved() function.

// Upon .parseAsync(), the resolved fields will be appended to the resulting value.
const UserWithResolved = zx.resolved(User);

By moving this relation data-fetching to the application boundary, we can easily include and exclude relation data, without altering our business logic in our functions.