feat(client): Middleware-centric public API

[nicobarray]

This PR fixes #30 and contains the following changes to the public API:

• no more createAqueduxClient, aqueduxReducer, wrapStoreReducer
• change aqueduxMiddleware to createAquedux

This change is intended to simplify the use of aquedux-client to:

import { applyMiddleware } from 'redux'
import { createStore, createAquedux } from 'aquedux-client'
import reducer from './reducers'

const aquedux = createAquedux({
  hydratedActionTypes: ['ADD_TODO', 'TOGGLE_TODO'],
  endpoint: `http://localhost:3001/aquedux`,
  channels: [ 'todos' ]
})

const store = createStore(reducer, applyMiddleware(aquedux))

As a result the new api contains 2 methods and 5 action creators:

• createAquedux
• createStore
• subscribe
• unsubscribe
• start
• stop
• restart

Internally the changes are as follow:

• Action creators are put at the root of the src/ folder
• constants/actionTypes have new action types for the client interaction (start, stop, restart)
• createAquedux creates the client and return the 3 internal middlewares chained.
• createClient implement a sockjs client with onopen, onclose, onmessage listeners. It also hooks listeners to our eventHub to communicate with the internal middlewares (onSend, onStop, onRestart, onStart). It auto starts the socket connection when invoked. The underlying createSocketClient is removed.
• index.js exposes the public API
• managers/ contains the same managers as before
• middlewares contains the 3 internal middlewares:
  • the channel middleware is in charge of subscribing and unsubscribing to channels
  • the client middleware is in charge of converting redux actions to client events
  • the router middleware is in charge of sending the appropriate action to the server and unpacking received actions

This version uses our event hub extensively to decouple the dependency between the store and the client.

The todo and todomvc are updated to match this version.

On the minor changes:

• The bunyan logger is removed as with most of the logs (the remaining ones are translated into console.log or throw new Error statements). Fixes #15
• The token localStorage key is now aquedux-jwt to have less chance of colliding with the used localStorage keys.
• The utils/index module has 2 new functions to compose the channel names.
• The eventHub has now an event enum.
• The redux-thunk dep is removed.

cc @chabou

[nicobarray]

After some test with the todo example, it seems that removing the restart action adds unfortunate behaviours:

• A join action triggers by a dispatch(subscribe('todos')) before the onOpen call result in a double join -> leave -> join sequence and therefore two channel snapshots.

To fix this, the router middleware is now called before the channel middleware that handles the internal subscription state AND the router middleware no longer synchronously call next(action) on internal actionTypes. There is no reason to have an exception here (cc @chabou if you see one here)

[nicobarray]

Ready to be merge for me 🐎 (tested on todo and todomvc examples)

[chabou]

Amazing job 🙏