fragmenta | command line tool

To begin here's a test page to get a handle on some of the issues (modify as desired and test in a browser to get details of document.scripts).

Your _basicProperty is a hot StateFlow, but you never use it for collecting anything. The property you have exposed, basicProperty, is a cold flow, so each subscriber that collects it will start a new run of the cold flow. Each of these cold flows will be posting their updates to the MutableStateFlow, so at that point, its state is unpredictable because it's showing the latest thing any collector of the shared cold flow is doing.

I think what you want is for there to be one flow of execution that's shared. So you should have a single StateFlow that is performing the connection, like this:

That's because your myData Observer will be immediately triggered with the latest data on back navigation and trigger the SUCCESS branch once again.

I recommend either using SharedFlows or checking out a SingleLiveEvent pattern for LiveData, where you can only consume an event once.

UPDATE:

A possible solution for the consumable pattern:

you can navigate using the fragment id

The reason for FragmentB's OnBackPressedCallback to be ignored is the way how OnBackPressedDispatcher treats its OnBackPressedCallbacks. They are run as chain-of-command, meaning that most recently registered one that is enabled will 'eat' the event so others will not receive it. Therefore, most recently registered callback inside FragmentScenario.onFragment() (which is enabled by lifecycleOwner, so whenever Fragment is at least in lifecycle STARTED state. Since fragment is visible during the test when backbutton is pressed, callback is always enabled at the time), will have priority over previously registered one in FragmentB.onCreateView(). Therefore, TestNavHostController's callback must be added before FragmentB.onCreateView() is executed.

This leads to changes in test code @Before method:

There's two main things to keep in mind:

1. replace() is the equivalent to calling remove() on every fragment currently added to that container, then calling add() with your new fragment, so that transaction with fragmentC is going to remove fragmentB as part of its operation
2. popBackStack() puts you exactly in the state you were in before the transaction. This means that fragmentC gets removed (the opposite of add()) and fragmentB gets added (the opposite of remove())

This means that it is expected that popping your fragmentC transaction will bring fragmentB back - your disallowAddToBackStack() just means that your fragmentB transaction can never be reversed.

This actually has some serious implications when it comes to mixing addToBackStack() and non-addToBackStack() fragment transactions on the same container: after you do your fragmentB transaction, there's no way to get back to fragmentA.

Generally, this means that if that was actually want you wanted, you replace your non-back stack fragmentB transaction with

You say you are getting a ClassCastException. The only class cast from the code you posted is

LiveData will always give you its current value upon loading the view again. If you dont want that then might I suggest moving to Kotlin Flow or MutableStateFlow

Update

If you updated your adapter data (or repository) which you should have done when when something changes like your button then called getProducts again to trigger the livedata observer to update your recyclerview you should get the data upon returning.

Here is an example of how I would do it

Example:

ViewModel