Testing the network and database layers

In this section, we are going to learn how to write tests for our network and database layers step by step.

Testing the network layer

To test our network layer, we will write unit tests. However, since we are using Retrofit to make our network requests, we will use MockWebServer to mock our network requests. The MockWebServer is a library that allows us to mock our network requests. Let us start by setting up the test dependencies in our version catalog:

1. Open the libs.version.toml file and add the following versions in the versions section:

   mockWebServer = "5.0.0-alpha.2"
   coroutinesTest = "1.7.3"
   truth = "1.1.5"

   We are setting up the versions for mockWebServer, coroutinesTest, and truth.

2. Next, in the libraries section, add the following:

   test-mock-webserver = { module = "com.squareup.okhttp3:mockwebserver", version.ref = "mockWebServer" }
   test-coroutines = { module = "org.jetbrains...