DOCUMENT_ADDED being dispatched multiple times per single add operation

Do you want to request a feature or report a bug?
I believe this to be a bug.

What is the current behavior? When you have multiple components listening to the same collection/key, it appears multiple listeners are added. This ends up producing the side effect of the corresponding ordered collection having new documents be inserted multiple times erroneously.

What is the expected behavior? When a document is added to a collection, DOCUMENT_ADDED should only fire once, and the ordered collection shouldn’t have any duplicates.

Which versions of dependencies, and which browser are affected by this issue? Did this work in previous versions or setups? redux-firestore@0.6.2 react-redux-firebase@3.0.0-alpha.6

Steps to reproduce and if possible a minimal demo of the problem via codesandbox or similar.

1. Add multiple components that connect to the same collection via firebaseConnect.
2. Ensure each component is mounted at least once.
3. Insert a new document into the collection from step 1.
4. Notice that DOCUMENT_ADDED fires multiple times and the corresponding ordered collection now contains duplicates.

Note: my scenario is that of a list view and several derived views (such as dashboards) on separate pages.

[gotdibbs]

@sbtgE I’ve corrected the underlying issue in my fork but I haven’t had time to sort out where the unit test fits in yet.

The workaround is to move the react-redux-firebase provider HOC up in the tree. For example, I changed this:

<Provider store={store}>
    <BrowserRouter>
        <ReactReduxFirebaseProvider {...rrfProps}>
            // ...
        </ReactReduxFirebaseProvider>
   </BrowserRouter>
</Provider>

…to this:

<Provider store={store}>
    <ReactReduxFirebaseProvider {...rrfProps}>
        <BrowserRouter>
            // ...
        </BrowserRouter>
   </ReactReduxFirebaseProvider>
</Provider>

[prescottprue]

If it is due to multiple listeners being attached for the same path, folks could try using oneListenerPerPath which will only attach one listener, which seems like the intention (since all of those components are connected to the same piece of state, you don’t need multiple listeners).

That said, in the future it may be smart to add warnings for this sort of thing since as mentioned, it is really the data that is wanted in all of the components - not multiple listeners attached at the same path. Right?