sagas | Saga pattern implementation

we decided to take the big plunge. upgrade the project from rn 61.5 to 67! it only took 2 days ;) wish we would have started there...

Sure, that's totally fine, and in fact we have a docs page on "SplittingReducer Logic" that even talks about that.

That said, you really should be using our official Redux Toolkit package to write your Redux logic. It will greatly simplify all your Redux code. In particular, it uses Immer to let you write "mutating" syntax in your reducers, and turns that into safe and correct immutable updates. No more object spreads!

There are multiple options

1 - Sending the navigate method as part of dispatched redux action

The answer you linked is right, the expected way for a saga to communicate back to component is through updating redux store. Adding promises/callbacks is an antipattern, because each action can be handled by 0-n sagas - of course you might know in your case it is just one saga, but the framework doesn't guarantee that in any way and so it can lead to some unexpected issues later on.

That said, even though it is an antipattern doesn't mean you can't do it.

The easier way is to add an callback to the action, so e.g.

My first inclination is to do what you proposed: include it in the payload of the action. The component knows the value, the saga needs the value, therefore it can pass the value in. This is likely the simplest solution.

Other than that... it kinda depends on the nature of the context value. Let's start with the simplest case and move to harder ones. Simplest case: There's only one copy of the context, and its value never changes. If it never changes, then it doesn't actually need to be in context. You can simply move the connectionObject into a file, export it, and then import it everywhere it's needed.

But you're using context, so it's probably a value that does change. So that brings us to the next case: There's only one copy, it's value does change, but only components care when it changes (the saga will just look it up when needed, and does not need to be notified). For this, i would probably have the context provider duplicate its state out to a global variable, which the saga checks.

Generally, when you write unit test the idea is to test every unit in isolation. So in your case, from the saga perspective the logic inside of redirectPos doesn't matter, all you need to test is that it gets called with the right parameter. Then, you can write another test specifically for the redirectPos function where you test the internals.

Testing current location can get a bit tricky, I suggest visiting other SO questions on that topic such as How to mock window.location.href with Jest + Vuejs?

The select effect creator accepts additional arguments after the selector function which are then send to the selector itself, so you can do this:

const person = yield select(makeGetPerson, id);

Docs: https://redux-saga.js.org/docs/api/#selectselector-args

You need to return promise from

I think the problem is that both tests use the same reference of SessionReducer._initialState. When you pass it to the state in withReducer, it isn't cloned in any way and so you end up working with the same object in memory.

There is lots of way how to fix it, e.g. you can have a method instead of a property to create the initial object: