redux-funk/dist/index.js

declarative async outerware for Redux

'use strict';

var queue = Symbol('actions');

module.exports.call = function (action, funk) {
  action[queue] = (action[queue] || []).concat([funk]);
};

// function from reducer to another reducer
// the new reducer adds a 'funks' key with declarative effects
// of type [func, [args]]
module.exports.coalesceFunks = function (reducer) {
  return function (state, action) {
    var nextState = reducer(state, action);
    var funks = action[queue] || [];
    // restore action to the way it was
    delete action[queue];
    return Object.assign({}, nextState, { funks: funks });
  };
};

// listen for store updates, and run each funk.
// `runFunks` assumes that each funk either returns nothing
// or returns a promise for an action.
// `runFunks` dispatches the actions
// You can replace `runFunks` with your own implementation
// if you prefer callbacks over promises, for example
module.exports.runFunks = function (store) {
  store.subscribe(function () {
    var funks = store.getState().funks || [];
    funks.forEach(function (funk) {
      var func = funk[0];
      var args = funk[1];
      var maybePromiseForAction = func.apply(null, args);
      if (!maybePromiseForAction || !maybePromiseForAction.then) {
        return;
      }
      maybePromiseForAction.then(store.dispatch);
    });
  });
};