examples VS just-api

Did you evaluate mock-service-worker? It's a good solution to mocking API requests. When it executes in the browser it uses a service worker to intercept requests, and when it executes in node (e.g. unit tests) it patches the http.Request methods to effectively do the same. Here's an example for mocking Apollo: https://github.com/mswjs/examples/tree/master/examples/graphql-react-apollo

I use https://mswjs.io/, here is also an example project that can become handy: https://github.com/mswjs/examples/tree/master/examples/graphql-react-apollo . Reading this article could also help: https://kentcdodds.com/blog/stop-mocking-fetch

would like to introduce Just-API, An open source framework that I built to help people with testing APIs.

To test the API, I recommend a proper API testing framework that can run a full test suite without you having to write a single test case. In this area, I recommend Dredd and schemathesis. These frameworks will get you covered when it comes to ensuring that the API server complies with the API specification. You may find Dredd a bit confusing at the beginning, in which case I recommend a tutorial I wrote a while ago about testing with Dredd. In addition, you can consider using just-apis, which allows you to define your own test cases for the API in YAML files (so no programming required).