@runtyped/type

TypeScript types disappear at run time. Runtyped changes that, preserving types at run time via a compiler plugin and enabling type-driven validation, serialization and more.

Started as a selective fork DeepKit focused on its type reflection capabilities. See Relationship to DeepKit.

Introduction

This package provides functions for type-driven validation, serialization, schema generation and more, leveraging the runtime reflection of type information provided by @runtyped/type-compiler (for TypeScript up to 6.x) or @runtyped/typescript (for TypeScript 7.x and later).

Check the documentation at https://github.com/runtyped/runtyped.

Installation - TypeScript 7.x (Go)

# Replaces the official `typescript` package, indentical CLI API.
# No need to run a separate patching script as required for older TypeScript
# versions.
npm i --dev @runtyped/typescript

# Install @runtyped/type as a run-time dependency.
npm i @runtyped/type

Installation - TypeScript 6.x

# Install @runtyped/type as a run-time dependency and @runtyped/type-compiler
# as a development or compile-time dependency.
npm i @runtyped/type
npm i --dev @runtyped/type-compiler

# Run the installer script to patch the TypeScript compiler with the Runtyped
# transformer. If npx is not available, the script should also be runnable via
# `./node_modules/.bin/runtyped-install-transformer`.
npx runtyped-install-transformer

Usage

import { is, cast, validate, serialize, typeOf, toJsonSchema } from '@runtyped/type';

interface User {
  id: number;
  registered: Date;
  username: string;
}

// Deserialize JSON to typed objects (strings become Dates, etc.)
const user = cast<User>({
  id: 1,
  registered: '2024-01-15T10:30:00Z',
  username: 'peter'
});
user.registered instanceof Date; // true

// Validate data against type
validate<User>({ id: 'not a number' });
// [{ path: 'id', message: 'Not a number' }]

// Serialize to JSON-safe output
serialize<User>(user);
// { id: 1, registered: '2024-01-15T10:30:00.000Z', username: 'peter' }

// Full runtime type reflection
const type = typeOf<User>();

// Convert type to JSON Schema
const schema = toJsonSchema<User>();

Versioning

See the Runtyped versioning strategy for details.

License

MIT (see LICENSE).