createStore

createStore.js

var EventEmitter = require('events').EventEmitter
  , mergeInto = require('react/lib/mergeInto');

function createStore(initialState) {
  var events = new EventEmitter();
  var state = initialState || {};

  return {

    setState: function(newState) {
      mergeInto(state, newState);
      this.emitChange();
    },

    set: function(attr, val) {
      state[attr] = val;
    },

    get: function(attr) {
      return state[attr];
    },

    getState: function() {
      return state;
    },

    addChangeListener: function (listener) {
      events.on('change', listener);
    },

    removeChangeListener: function (listener) {
      events.removeListener('change', listener);
    },

    emitChange: function() {
      events.emit('change');
    }
  };
};

module.exports = createStore;

createStore.test.js

var createStore = require('../createStore');

describe('createStore', function () {
  describe('#initialize', function() {
    it('set data into store', function() {
      var MyStore = createStore({name: 'Joe', age: 35});
      assert(MyStore.get('name') === 'Joe');
      assert(MyStore.get('age') === 35);
    });
  });

  describe('#setState', function() {
    it('sets the state and triggers an event emitter', function(done) {
      var MyStore = createStore({name: 'Joe', age: 35});

      var eventReceiver = function() {
        assert(this.get('foo') === 'bar');
        assert(this.get('baz') === 'bop');
        assert(true, 'event was triggered');
        done();
      };

      MyStore.addChangeListener(eventReceiver.bind(MyStore));

      MyStore.setState({
        foo: 'bar',
        baz: 'bop'
      });
    })
  });
});

Usage:

// creating the store
var createStore = require('../wherever/createStore');

var SomeStore = module.exports = createStore({
  users: [],
  whatever: false
});

// in a component

React.createClass({
  componentDidMount: function() {
    SomeStore.addChangeListener(this.onChange);
  }
});