From my experience as a software developer, an issue that I have dealt when building an application are the dependencies for external services. A test with external dependencies where you don’t have much control can fail if there is a change in the service and the outcome is not the expected, with this in mind, we need to ensure the non-dependence of external services when running our tests. The most effective way to do this is mocking those dependencies.
In this post, I will focus on the functional tests of an application. I will also talk about how to mock an external service to not rely on it when running our functional tests.
To explain how to mock an external service, I’ll walk you step by step through an example.
Let’s say that we have an endpoint, that is using a third-party package called holidays that is making HTTP requests to an external service to get such holidays.