mpeyper
commented
5 years ago Could symbol-observable be added to the store using an enhancer rather than adding it by default?
import $$observable from 'symbol-observable'
export const asObservable = (createStore) => (...args) => {
const store = createStore(...args)
store.observable = function() {
const outerSubscribe = store.subscribe
return {
subscribe(observer) {
if (typeof observer !== 'object' || observer === null) {
throw new TypeError('Expected the observer to be an object.')
}
function observeState() {
const observerAsObserver = observer
if (observerAsObserver.next) {
observerAsObserver.next(getState())
}
}
observeState()
const unsubscribe = outerSubscribe(observeState)
return { unsubscribe }
}
[$$observable]() {
return this // not sure if this should be `this` or `store`
}
}
}
return store
}const store = createStore(reducer, asObservable)
const store = createStore(reducer, compose(asObservable, applyMiddleware(epicMiddleware)))The enhancer could be a separate package, included in redux-observable or as a distinct import (e.g. import { asObservable } from 'redux/observable')
This was just a thought when I saw your tweet. It may not be practical or even work at all.
markerikson
timdorr
Andarist
jednano
We currently have two external dependencies: https://github.com/zertosh/loose-envify and https://github.com/benlesh/symbol-observable .
loose-envifyappears to be used inpackage.json, but only as some kind of polyfill / build plugin for Browserify:https://github.com/reduxjs/redux/blob/85024d431ca765c843561be6792edeb7890d5fce/package.json#L102-L106
symbol-observableis used increateStoreas a polyfill forSymbol.observable, to allow compatibility for treating the Redux store as an observable:https://github.com/reduxjs/redux/blob/85024d431ca765c843561be6792edeb7890d5fce/src/createStore.ts#L1
https://github.com/reduxjs/redux/blob/85024d431ca765c843561be6792edeb7890d5fce/src/createStore.ts#L331-L333
I would like to strongly consider dropping both of those dependencies if at all possible.
I question whether we need to have any specific support for Browserify in here. If there's a build step that needs to be done, let the end users take care of it. No reason to have an installation dep just for that.
symbol-observableboils down to this 15-line file for the polyfill plus another 15 lines for figuring out what the global object is.@davidkpiano suggests rolling our own
symbol-observableif really needed.Finally, we are currently talking about adding
ts-toolbeltas a dependency for itscomposefunction. I would like us to seriously investigate whatever other alternatives are out there to adding a dep, even if it's one that ultimately compiles away.