fix(#285): add composeWithStateSync to resolve issues with enhancer order

[sneljo1]

As discussed in #285. Added a new composeWithStateSync function which mimics the composer function and should replace that function when using more than one enhancer. When using one enhancer, the other API is still the same.

To accommodate this, I have also added 2 more things:

• preventActionReplay was added to the options because in extensionCompose() we re-use the stateSyncEnhancer, but we do not want the actions to start forwarding there because then it will not pick up the ones dispatched by the middleware. We rather want them to start forwarding in the last part of the chain, hence forwardActionEnhancer. This is also possible with denyList, but I thought this was cleaner. WDYT?
• To simplify the compose function, I have opted to check whether in renderer or main process, inside the lib. With that, I have also added a helper function stateSyncEnhancer which can wrap around the process specific enhancer to do the same thing.

Will see if I can write a test for it tomorrow. Do you want me to go ahead and update the README already as well @matmalkowski ?

[CLAassistant]

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[matmalkowski]

Thanks for the contribution!

We will try to take a look at the change in next few days, you could also add some info into the README file, like you mentioned. I've also started a docs page for the project (/docs folder) - you might as well add a paragraph there or just add a placeholder so we can cover it later.

@Slapbox if you have some time, you might also take a look at this branch & try it with your issue #294 and redux-saga

[Nantris]

I'd really like to give this a try!

Unfortunately my TypeScript noobishness may be getting in the way.

I cloned the repo, checked out the alpha branch, and ran yarn && yarn build, but I get an error like rollup has no idea what TypeScript is. Am I overlooking something obvious?

[Nantris]

Friggin' Windows... Builds fine on Linux, will update soon.

[Nantris]

@Superjo149 there's no code changes needed on our end to take advantage of these changes, right?

Unfortunately it doesn't seem to remedy the issue with Redux Saga.

I took a look at how to setup RxJS and it looks very similar to setting up sagas. Can you share the part of your store configuration where you're applying your enhancers and middlewares so I can compare it with our setup?

I also tried importing composeWithStateSync and replacing our compose with that, but that leads to Error: Attempted to register a second handler for 'electron-redux.INIT_STATE_ASYNC'

[sneljo1]

@Superjo149 there's no code changes needed on our end to take advantage of these changes, right?

Unfortunately it doesn't seem to remedy the issue with Redux Saga.

I took a look at how to setup RxJS and it looks very similar to setting up sagas. Can you share the part of your store configuration where you're applying your enhancers and middlewares so I can compare it with our setup?

I also tried importing composeWithStateSync and replacing our compose with that, but that leads to Error: Attempted to register a second handler for 'electron-redux.INIT_STATE_ASYNC'

@Slapbox There is some kind of code change required, yes. I will properly document this tomorrow along with the tests. But this is the jist. The error sounds like your are using both the old API and the compose function.

Current approach:

Just selected the main process here as an example.

const middleware = applyMiddleware(countMiddleware)
const enhancer = compose(middleware, mainStateSyncEnhancer())
const store = createStore(reducer, defaultState, enhancer)

Approach with multiple enhancers (Saga middleware,... etc) using composeWithStateSync:

Note that when using composeWithStateSync, neither mainStateSyncEnhancer or rendererStateSyncEnhancer are required as this will be handled by the compose function. This in line with how redux-devtools-extension works. Also note that this needs to be done in both processes.

const middleware = applyMiddleware(countMiddleware)
const enhancer = composeWithStateSync(middleware)
const store = createStore(reducer, defaultState, enhancer)

[Nantris]

@Superjo149 thanks so much for your help, that makes perfect sense now and I can confirm that everything seems to work properly!

Not only a fix, but a further streamlining of an already great API; wow, great work!

PS: Is there a way to get Redux Devtools working with this too?

[Nantris]

Oh, you can just wrap compose functions around compose functions. Never knew that, so that's the solution for Redux Devtools in case anyone is lurking this thread.

[matmalkowski]

:tada: This PR is included in version 2.0.0-alpha.8 :tada:

The release is available on:

• npm package (@alpha dist-tag)
• GitHub release

Your semantic-release bot :package::rocket:

[sneljo1]

Glad I could contribute to this 🎉