@lud @ityonemo Thank you for your responses!
@lud yes, you are right, but it knows the correct name. In the actual use case, this module receives various parameters and generates the GenServer name based on them. I just wanted to simplify the example and didn’t specify this, I’m sorry about that. Then, the other processes that update the GenServer state (which are actually controller actions), also receive a parameter that lets them know the name of the GenServer.
@ityonemo your observations are correct. In simplifying the code for my question, I made a few errors. We use {:global, "different_id"} for the GenServer name, and the GenServer itself is started with ServerName.start_link({:global, "different_id"} and in start_link/1 it has GenServer.start_link(__MODULE__, %{}, [name: name]). I hope this answers the first half of your response.
About the call and cast - I think you have a point. It would be safer with call, there is no concrete reason to use cast I think, although so far we have had no problems with it. I did not originally write this functionality, but I am trying to refactor it at the moment, and this suggestion is good, thank you!
As for the test itself, well, the case itself is a bit strange. I want to the test the module that starts the GenServer, not the GenServer itself. So in the test I call the module and it starts the GenServer, but as I pass the parameters to the module, I know the GenServer name.
Normally, this module waits for HTTP requests to an endpoint in the same application - the GenServer.cast calls are made in the controller once per request. Once all requests have been received, the GenServer’s state is complete and the other module unblocks and continues processing these responses. With these casts in the test I try to simulate that. Actually, it might be better if I mock the requests themselves and call the controller in the test, but I don’t find it necessary as I’m not aiming for an integration test, just a test for one specific module.
I know the blocking part while waiting for the GenServer state to get update from elsewhere might seem strange and has a downside, I will probably refactor this too at some point, but it will requite a lot of changes to other parts of the application too, that is why for the time being I want to test the current functionality.
In addition, @jtsummers, thank you fro the diagram and the suggestions!
