Jazzer.js

Jazzer.js is a coverage-guided, in-process fuzzer for the Node.js platform developed by Code Intelligence. It is based on libFuzzer and brings many of its instrumentation-powered mutation features to the JavaScript ecosystem.

It can be used in two ways: with dedicated fuzz targets, a module exporting a function that receives the fuzzer data and is started with npx jazzer, or integrated into the Jest test framework, which is the recommended approach to fuzz code in the normal development workflow. Bug detectors report issues such as command injection or prototype pollution in addition to uncaught exceptions.

Jazzer.js is free and open source under the Apache 2.0 licence, installed as the @jazzer.js/core npm package.