End-to-end testing mostly refers to testing the whole application, which includes the controller layer, the service layer, the database, and any third-party layer. The purpose of end-to-end testing is to make sure that every component in the system is performing well and in a manner that they are supposed to. No dependency is supposed to mock in end-to-end testing. This testing is supposed to be done as an assumption of the end user, as it is using this application.
End-to-end testing in monolithic tries to cover all the possible scenarios in the application. On the contrary, the word application has very much changed in the context of microservices. In microservice architecture, every microservice itself is a small and independent application. As in a microservice, everything is distributed, so testing the whole application is challenging in itself. There are many questions raised in E2E testing, what to cover, how much to cover, and the dimensions are also diverse in...