RetrofitTestRule

JUnit test rule for testing retrofit services

Generally we don't unit test retrofit interfaces. But if you would like to have an integration test for the retrofit interfaces, then this test rule can be handy. This rule can be used as an integration test to make sure the retrofit service configuration is correct

Configuration

testImplementation("io.github.thomsontomy:testrule:0.4.0")

Example

Imagine you have an awesome retrofit service class like below

interface GitHubService {
    @GET("users/{user}/repos")
    suspend fun listRepos(@Path("user") user: String): List<GithubRepo>
}

The integration test would look like this

class GitHubServiceTest {
    @get:Rule
    val retrofitTestRule = RetrofitTestRule(GitHubService::class.java, logLevel = LogLevel.BODY)

    @Test
    @RestRequest(
        validations = RequestValidations(
            path = "/users/my_user/repos",
            method = "GET"
        ), // Validations on the request
        responseOptions = ResponseOptions(bodyText = "[]") // Response configurations
    )
    fun testListRepos() = runTest {
        // Get the service instance
        val service = retrofitTestRule.getService()

        // Make the API call
        service.listRepos("my_user")
    }
}

Under the hood

This rule makes use of OkHttp's MockWebServer and creates a mock server for the retrofit service to use.