variant

Creates a variant schema.

// Variant schema with an optional pipe
const Schema = variant<TKey, TOptions>(key, options, pipe);

// Variant schema with an optional message and pipe
const Schema = variant<TKey, TOptions>(key, options, message, pipe);

Generics

TKey extends string
TOptions extends VariantOptions<TKey>

Parameters

key TKey
options TOptions
message ErrorMessage | undefined
pipe Pipe<Output<TOptions[number]>> | undefined

Explanation

With variant you can validate if the input matches one of the given object options. The object schema to be used for the validation is determined by the discriminator key. With pipe you can transform and validate the further details of the variant. If the input does not match a schema and cannot be clearly assigned to one of the options, you can use message to customize the error message.

Returns

Schema VariantSchema<TKey, TOptions>

Examples

The following examples show how variant can be used.

Variant schema

Schema to validate an email, URL or date variant.

const VariantSchema = variant('type', [
  object({
    type: literal('email'),
    email: string([email()]),
  }),
  object({
    type: literal('url'),
    url: string([url()]),
  }),
  object({
    type: literal('date'),
    date: string([isoDate()]),
  }),
]);

Nested variant schema

You can also nest variant schemas.

const NestedVariantSchema = variant('type', [
  VariantSchema,
  object({
    type: literal('color'),
    date: string([hexColor()]),
  }),
]);

The following APIs can be combined with variant.

Schemas

object

Methods

Transformations

toCustom

Validations

custom