Introduction

@typeofweb/schema is a lightweight and extensible library for data validation with full TypeScript support!

Validation

import { number, object, optional, string, validate } from '@typeofweb/schema';

const personSchema = object({
  name: string(),
  age: number(),
  email: optional(string()),
})();

const mark = {
  name: 'Mark',
  age: 29,
};

const personValidator = validate(personSchema);

const validatedPerson = personValidator(mark);
// returns
// {
//   readonly name: string;
//   readonly age: number;
//   readonly email?: string | undefined;
// }

Intuitive coercion

import { number, object, date, validate } from '@typeofweb/schema';

const userQuery = object({
  dob: date(),
  query: number(),
})();

const payload = {
  dob: '2001-04-16T00:00:00.000Z',
  query: '123',
};

const userQueryValidator = validate(userQuery);

const result = userQueryValidator(payload);
// returns
// {
//   readonly dob: Date;
//   readonly query: number;
// }

Descriptive errors

import { string, object, array, validate } from '@typeofweb/schema';

const validator = validate(array(object({ a: string() })())());

const result = validator([123]);
// throws ValidationError: Invalid type! Expected { a: string }[] but got [123]!

Types generated from validators

import { number, object, optional, string, TypeOf } from '@typeofweb/schema';

const personSchema = object({
  name: string(),
  age: number(),
  email: optional(string()),
})();

type Person = TypeOf<typeof personSchema>;
// type Person = {
//   readonly name: string;
//   readonly age: number;
//   readonly email?: string | undefined;
// }