A tiny invariant function

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

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

complex type validators that generate TypeScript and Flow types for you

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

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

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™.

Typescript testing library with pipeline-like testing feature

Runtime type assertions that return

Assertion library for Testy.Ts

Santi's Assertion Library. Official repo for NPM package @santi100a/assertion-lib.

Runtime object parsing and validation with static TypeScript typing.

🔥 TypeScript type assertion plugin for vitest

Store test fixtures in files and assert on them

🔥 Micro TypeScript assertion (test) library.

Assertion collection for JavaScript data

TAP plugin for JSON schema

Composable and checkable JavaScript (and TypeScript) data structure

An extensible assertion library for JavaScript, based on Hamcrest