/ Choose Clobbr - API load & speed test if
Its stated focus matches what you need: Clobbr is a developer tool that allows you to load & speed test your API endpoints to see how well they perform under load from multiple requests (clobber your APIs!), in sequence or parallel. Regardless if you're testing a REST, GraphQL or cloud function Clobbr has got you covered!
/ Choose the fun, simple, flexible JavaScript test framework if
Its stated focus is closer to your workflow: Mocha is a feature-rich JavaScript test framework running on Node.js and in the browser, making asynchronous testing simple and fun. Mocha tests run serially, allowing for flexible and accurate reporting, while mapping uncaught exceptions to the correct test cases. Hosted on GitHub.