A tiny invariant function

🐷 Poku makes testing easy for Node.js, Bun, Deno, and you at the same time.

Simple utility for runtime type checking which also assigns the correct type if used with TypeScript.

Playing with spok inside Cypress

complex type validators that generate TypeScript and Flow types for you

Decorator Contracts is a library that provides the ability to create and assign Code Contracts to ECMAScript and TypeScript classes. This enables enforcement of the Liskov substitution principle and the Open-closed principle of SOLID to support Design By Contract™.

API input validators with user-friendly error output and TypeScript to ensure you don't miss any properties

Tiny zero-dependency tool for library authors to create assertion functions with clean strack traces.

🔥 TypeScript type assertion plugin for vitest

A TypeScript library that provides borrowing mechanisms via assertion functions

🔥 Micro TypeScript assertion (test) library.

Assertion collection for JavaScript data

TAP plugin for JSON schema

Simple lightweight library for enhancing plain JS objects with TypeScript wrappers enabling easy API data assertion and validation.

Typescript testing library with pipeline-like testing feature

Store test fixtures in files and assert on them

Minimal assertion library for TypeScript (and JavaScript)

Runtime type assertions that return

Test-agnostic assertion library for ROBLOX.