Testing Kotlin Flows in Android using Turbine

In this article, we will explore some tips and techniques for testing Kotlin Flows in Android apps, helping you write more reliable and robust code.

Why is this important?

Testing is an essential part of software development, and it becomes even more critical when working with asynchronous code like Flows.

Setup

Go ahead to :app/build.gradle and add Turbine.

dependencies {
    // You can also use JUnit instead of kotlin-test
    testImplementation("org.jetbrains.kotlin:kotlin-test")
    testImplementation("app.cash.turbine:turbine:0.12.1")
}

What is Turbine and how it works?

Turbine is a small testing library for Kotlin Flows. A Turbine is a thin wrapper over a Channel with an API designed for testing.

Functions

awaitItem() — Suspends the function and awaits the new value to be sent to the Turbine .

awaitComplete() — Suspends the function until the Turbine completes without an exception.

awaitError() — Suspends the function until the Turbine completes with a Throwable .

Testing A Single Flow