Android - Launching fragment passing navigation args using espresso

Question

I'm testing my fragments on espresso using something like this:

launchFragmentInContainer<ErrorManagerFragment>(themeResId = R.style.MaterialTheme)

However, my ErrorManagerFragment needs an argument and I can't figure out how to pass it to my fragment.

internal class ErrorManagerFragment : Fragment(R.layout.fragment_error_manager) {

    private val navArgs: ErrorManagerFragmentArgs by navArgs()
    private val attemptNumber by lazy { navArgs.StringNumAttemptError }

    ...
}

I tried a couple of solutions I found on the internet but they are not working as well.

Answer 1

Each NavArgs class allows you to construct an instance directly from its values - i.e., you can use ErrorManagerFragmentArgs(15) to construct a ErrorManagerFragmentArgs instance. This can be transformed into a Bundle by using the toBundle() method that every Args class has, allowing you to pass that to your launchFragmentInContainer call:

val args = ErrorManagerFragmentArgs(15)
launchFragmentInContainer<ErrorManagerFragment>(
    themeResId = R.style.MaterialTheme,
    fragmentArgs = args.toBundle()
)