Assert Packages

Type check values

The assert module from Node.js, for the browser.

String validation and sanitization

A tiny invariant function

A little library for asserting types and values, with zero dependencies.

BDD/TDD assertion library for node.js and the browser. Test framework agnostic.

JavaScript test spies, stubs and mocks.

Better assertions for node, reporting the expr, filename, lineno etc

flow typed nullthrows

Next-gen browser and mobile automation test framework for Node.js

assert with status codes

Validate XML, Parse XML, Build XML without C/C++ based libraries

tap-producing test harness for node and browsers

Function argument validation for humans

test framework agnostic BDD-style assertions

Helper function for exhaustive checks of discriminated unions in TypeScript

Precondition checking utilities.

Utilities to get and check variable types (isString, isPlainObject, isRegExp, etc)

Hook and modify stdout and stderr

Power Assert feature enhancer for assert function/object