jest – Zebra Codes

How to Mock a Library with NodeJS, TypeScript, and Jest

18th September, 2023

The ability to provide a mock implementation of functionality is essential to unit testing, however the method for doing so with Jest and TypeScript is not well documented. This tutorial aims to elucidate the method for mocking a JavaScript library that is loaded into your TypeScript project. This is demonstrated with the ws WebSocket library but applies equally to any library, including built-in NodeJS modules.

How to Mock an HTTP Request in NodeJS with JEST

6th February, 2023

NodeJS jest unit testing

Performing a real HTTP request in a unit test can make it slow and brittle, so the solution is to mock the Node HTTP library. This guide will show you how to create mock objects that simulate successful and unsuccessful HTTP requests.