idea: allow injecting wrappers to support different async paradigms

[yoshuawuyts]

I'm a huge fan of pull-stream, and would love to have it be a first-class citizen in choo. But I know that people can be picky about their preferences for async paradigms, so I reckon the best solution would be to add some sort of wrapping hook so choo can be extended to accomodate all flavors of async at no extra cost.

I reckon the API could be something like:

// each wrapper expects a function to be returned
app({
  wrapSubscriptions: (fn) => {},
  wrapReducers: (fn) => {},
  wrapEffects: (fn) => {}
})

With a little node core streams example (as that's the paradigm I'm most comfortable with):

const from = require('from2')
const pump = require('pump')

const app = choo({
  wrapEffect: (fn) => {
    return (data, state, send, done) => {
      const source = from(data)
      const sink = fn(state, send)
      pump(source, sink, (err, res) => {
        if (err) return done(err)
        done(null, res)
      })
    }
  }
})

Lil consideration I have if the API names should be plural or singular. Also if this idea makes sense at all, hah 😛 - reckon if done well enough it could ease up some of the (unfortunately necessary) rough edges around async that were introduced in v3. Thanks! ✨

[timwis]

Would run-series/run-parallel be another use case? Haven't used pull streams before so just trying to visualize.

[yoshuawuyts]

@timwis run-series / run-parallel operate on callbacks, so they should be fine in the current setup I reckon. Other stuff could for example be a Promise wrapper, or async / await (though I refuse to ever let any Promise / a/a examples slip in haha)

[yoshuawuyts]

This was added in choo@3.3.0 🎉 - closing!