Testing Kotlin Flows
In this section, we will focus on testing Kotlin Flows. We can create unit and integration tests for classes such as ViewModel
that use Flow in their code.
To test code that collects a Flow, you can use a mock object that can return values which you can do assertion checks. For example, if your ViewModel
listens to the Flow from a repository, you can create a custom Repository
class that emits a Flow with a predefined set of values for easier testing.
For example, say you have a MovieViewModel
class such as the following that has a fetchMovies
function that collects a Flow:
class MovieViewModel(private val movieRepository:
MovieRepository) {
...
suspend fun fetchMovies() {
movieRepository.fetchMovies().collect {
_movies.value = it
...