Pretender.js

What Pretender.js is

Pretender.js is a free, open-source mock server library for XMLHttpRequest and Fetch in the browser. It temporarily replaces the native request objects so developers can define routes and handlers with an Express- or Sinatra-style syntax. The routing DSL includes get, put, post, delete, patch, and head methods. Handlers can return an HTTP status, headers, and body, or return a Promise. Routes may respond synchronously, asynchronously, after a delay, or only when manually resolved. A route can also pass requests through to native XMLHttpRequest. Pretender tracks handlers and handled, unhandled, and pass-through requests, with an option to disable tracking. The README documents npm or Yarn installation, direct browser loading, and module imports. Call shutdown() when finished to restore native XMLHttpRequest. The project uses the MIT license, and its repository provides an Issues page for reports and discussion.