Testing the application with end-to-end tests

The final form of testing we will cover is end-to-end (E2E) testing. E2E testing will encompass the entire application, including third-party services, and have nothing replaced with any test doubles. The tests should cover all of the processes in the application, which could result in very large tests that take a long time to complete:

Figure 10.11 – The scope of an end-to-end test

E2E testing takes many forms, and the one we will be using is a features-based approach. We will use Gherkin, introduced in Chapter 3, Design and Planning, to write plain text scenarios that should cover all essential flows throughout the application.

Relationship with behavior-driven development

You can do behavior-driven development (BDD) without also doing E2E testing, and vice versa. These two are sometimes confused with each other or it’s thought that they are the same. BDD, as a practice, can be used at all...