MockReducerManager.addReducers is not a function when testing

[nagyadam2092]

As per the guideline states, I already asked my general support question on SO: https://stackoverflow.com/questions/64715061/addreducer-missing-on-mockstore
but didn't get any answers yet, so I opened an Issue instead, sorry if this is still not following the guidelines.
Basically my question is that what is the proposed setup if my code uses ReducerManager.addReducers in a test environment. Our setup relies on dynamically adding reducers to the store, but this ReducerManager.addReducers call breaks tests with this error: this.reducerManager.addReducers is not a function.
What is the suggested way of testing modules that are calling ReducerManager.addReducers? Maybe adding this as noop calls would solve the issue? (like this PR: https://github.com/ngrx/platform/pull/2265/files)

[alex-okrushko]

Hi @nagyadam2092
Thank you for going with the guideline recommendation at first. Btw, we also have a Discord Server now (discord.gg/ngrx) - it's one of the fastest way to bring it to the community's attention.

You are right - adding these methods and making them a noop should solve your immediate issue.

In the meantime you might to extend MockReducerManager in your code and provide it in your tests instead.

Do you want to send a PR for the fix?

[nagyadam2092]

Thanks for the reply @alex-okrushko ! Didn't know about the Discord community, going to check it!
Opened #2777 for the quick fix of the described behaviour.