Yup

Yup is a schema builder for runtime value parsing and validation. Define a schema, transform a value to match, assert the shape of an existing value, or both. Yup schema are extremely expressive and allow modeling complex, interdependent validations, or value transformation.

You are viewing docs for the v1.0.0 of yup, pre-v1 docs are available: here

Killer Features:

Concise yet expressive schema interface, equipped to model simple to complex data models
Powerful TypeScript support. Infer static types from schema, or ensure schema correctly implement a type
Built-in async validation support. Model server-side and client-side validation equally well
Extensible: add your own type-safe methods and schema
Rich error details, make debugging a breeze
Compatible with Standard Schema

Getting Started

Schema are comprised of parsing actions (transforms) as well as assertions (tests) about the input value. Validate an input value to parse it and run the configured set of assertions. Chain together methods to build a schema.

import { object, string, number, date, InferType } from 'yup';

let userSchema = object({
  name: string().required(),
  age: number().required().positive().integer(),
  email: string().email(),
  website: string().url().nullable(),
  createdOn: date().default(() => new Date()),
});

// parse and assert validity
let user = await userSchema.validate(await fetchUser());

type User = InferType<typeof userSchema>;
/* {
  name: string;
  age: number;
  email?: string | undefined
  website?: string | null | undefined
  createdOn: Date
}*/

Use a schema to coerce or "cast" an input value into the correct type, and optionally transform that value into more concrete and specific values, without making further assertions.

// Attempts to coerce values to the correct type
let parsedUser = userSchema.cast({
  name: 'jimmy',
  age: '24',
  createdOn: '2014-09-23T19:25:25Z',
});
// ✅  { name: 'jimmy', age: 24, createdOn: Date }

Know that your input value is already parsed? You can "strictly" validate an input, and avoid the overhead of running parsing logic.

// ❌  ValidationError "age is not a number"
let parsedUser = await userSchema.validate(
  {
    name: 'jimmy',
    age: '24',
  },
  { strict: true },
);

Schema basics
TypeScript integration
Error message customization
- localization and i18n
Standard Schema Support
API

Yup

Install / Use

README

Yup

Getting Started

Table of Contents