How to transform schema to conform to z.object() shape?

[chrisjansky]

Hi,

I am very fond of using valibot in nuxt and have migrated all validator logic to it from zod. The recent v3 of nuxt/content has introduced a schema requirement for content like this:

 goods: defineCollection({
      type: "data",
      source: "goods/*.json",
      schema: z.object({
        price: z.number(),
        ...
      }),
    })

I have raised an issue in nuxt/content to offer a more generic way to define schema without relying on a specific stack, ideally through https://standardschema.dev.

Realistically that’s not going to happen any time soon, so is there any way to work around that and give nuxt/content what it needs without maintaining two sets of validator schemas (valibot application-wide, zod for nuxt/content)?

Basically a transformer function that maps it to the shape of ZodObject.

Any help appreciated 🌈

[fabian-hiller]

Yes, it is possible to write such a function. Valibot schemas store any information in their objects. For example, via objectSchema.entries you can access the shape of the object schema.

[fabian-hiller]

Quick tip: You can put a schema in JSON.stringify(Schema, null, 2) and log it to the console to see its full structure.

[chrisjansky]

@fabian-hiller Hi Fabian, thanks for the reply.

It appears that ZodObject expected by defineCollection.schema in nuxt/content should provide the methods that are used for internal validation logic of the module.

Doing simple comparison like this:

const zodSchema = z.object({
  price: z.number(),
})
console.log(JSON.stringify(zodSchema, null, 2))

const vSchema = v.object({
  price: v.number(),
})
console.log(JSON.stringify(vSchema, null, 2))

Prints:

// zod
{
  "_def": {
    "unknownKeys": "strip",
    "catchall": {
      "_def": {
        "typeName": "ZodNever"
      },
      "~standard": {
        "version": 1,
        "vendor": "zod"
      }
    },
    "typeName": "ZodObject"
  },
  "~standard": {
    "version": 1,
    "vendor": "zod"
  },
  "_cached": null
}
// valibot
{
  "kind": "schema",
  "type": "object",
  "expects": "Object",
  "async": false,
  "entries": {
    "price": {
      "kind": "schema",
      "type": "number",
      "expects": "number",
      "async": false,
      "~standard": {
        "version": 1,
        "vendor": "valibot"
      }
    }
  },
  "~standard": {
    "version": 1,
    "vendor": "valibot"
  }
}

While stringified v.object stores the shape in entries, z.object contains no unique information about the shape and has shape property on the zodObject object before stringification instead.

Transforming a plain JSON object from one into another would be doable, but this looks like far outside my skill set. Long story short my best bet is to wait for @nuxt/content to implement https://standardschema.dev/ 😢

[sillvva]

JSON.stringify does not include properties that are not valid JSON, like functions. The ~standard property in both Zod and Valibot include a validate function.

https://valibot.dev/playground/?code=JYWwDg9gTgLgBAKjgQwM5wG5wGZQiOAcg2QBtgAjCGQgbgCh6BjCAO1XgGUmALAUxDI4AXkwA6CBQBWfJjAAUAb3pw4A5MFIAucWGBg+8jGI5RgrAObyAlABpx6zTbsq4YNKgDu0ACY7jegZGJjBmljb2xiDmADJ8ljA88gAc1i4AvtYMzGwccFB8qACupPCi3PyCANoARAB+HMisPshQPjUAumIk5C0whsqqjtpEUk18AAJ8AB7I4KR8YiwghLau7qhevjqEAIwATADMACwArABsAOzJq-SZ2SzsEAtipBBWBcWlWfRAA

Schema["~standard"].validate(value)

And yeah, you'll probably need to wait for the Nuxt team to implement the Standard Schema or use Zod schemas for your collections in the mean time.