transform

Creates a custom transformation action.

const Action = v.transform<TInput, TOutput>(action);

Generics

• TInput extends any
• TOutput extends any

Parameters

• action (input: TInput) => TOutput

Explanation

transform can be used to freely transform the input. The action parameter is a function that takes the input and returns the transformed output.

Returns

• Action TransformAction<TInput, TOutput>

Examples

The following examples show how transform can be used.

Transform to length

Schema that transforms a string to its length.

const StringLengthSchema = v.pipe(
  v.string(),
  v.transform((input) => input.length)
);

Add object entry

Schema that transforms an object to add an entry.

const UserSchema = v.pipe(
  v.object({ name: v.string(), age: v.number() }),
  v.transform((input) => ({
    ...input,
    created: new Date().toISOString(),
  }))
);

Related

The following APIs can be combined with transform.

Schemas

• any,
• array,
• bigint,
• blob,
• boolean,
• custom,
• date,
• enum,
• file,
• function,
• instance,
• intersect,
• lazy,
• literal,
• looseObject,
• looseTuple,
• map,
• nan,
• never,
• nonNullable,
• nonNullish,
• nonOptional,
• null,
• nullable,
• nullish,
• number,
• object,
• objectWithRest,
• optional,
• picklist,
• promise,
• record,
• set,
• strictObject,
• strictTuple,
• string,
• symbol,
• tuple,
• tupleWithRest,
• undefined,
• undefinedable,
• union,
• unknown,
• variant,
• void

Methods

• pipe

Utils

• isOfKind,
• isOfType