redux-action/build/create-reducer.js

redux action utils

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

exports.default = createReducer;

var _util = require('./util');

var _clone = require('clone');

var _clone2 = _interopRequireDefault(_clone);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

var assign = Object.assign;

/**
 * @param {Object} handlers
 * @param {Object} defaultState
 */

function createReducer(defaultState, handlers) {
  if ((typeof defaultState === 'undefined' ? 'undefined' : _typeof(defaultState)) !== 'object') {
    return (0, _util.throwError)('invalid defaultState');
  }

  if ((typeof handlers === 'undefined' ? 'undefined' : _typeof(handlers)) !== 'object') {
    return (0, _util.throwError)('invalid handlers');
  }

  return function () {
    var state = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : defaultState;
    var action = arguments[1];

    var type = action.type;

    // TODO: check Immutable data type

    if (!type) {
      return assign({}, state);
    }

    var handler = handlers[type];

    if (!(0, _util.isFunc)(handler)) {
      return assign({}, state);
    }

    return (0, _clone2.default)(assign({}, state, executeHandler(handler, state, action)));
  };
}

/**
 * private
 */

function executeHandler(handler, state, action) {
  var result = void 0;

  if (action.hasOwnProperty('payload')) {
    result = handler(action.payload, state, action);
  } else {
    // TODO: remove this, only standard `payload`
    console.warn('non standard action support will be removed');
    result = handler(pickAction(action), state, action);
  }

  return assign({}, state, result);
}

function pickAction(action) {
  var ignoreKeys = ['type', 'payload', 'error', 'meta'];
  var payload = {};

  Object.keys(action).forEach(function (key) {
    if (ignoreKeys.indexOf(key) === -1) {
      payload[key] = action[key];
    }
  });

  return payload;
}