reducers-creator/reducersCreator.js

Reducers Creator is an awesome tiny javascript package that allows you to easily and intuitively create reducer functions. Mainly used to create redux reducers.

"use strict";

/**
 * Copyright (c) 2020-present Ruben Arushanyan (https://github.com/ruben-arushanyan)
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 * 
 */
var _require = require('immer'),
    produce = _require.produce;

var _require2 = require('./utils'),
    isString = _require2.isString,
    isUndefined = _require2.isUndefined,
    isObject = _require2.isObject;

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

var reducersCreator = function reducersCreator(reducer_name, initial_state, reducer_tree) {
  if (!isString(reducer_name)) {
    throw new TypeError('reducer name must be the String');
  }

  var reducerHandlers = reducerTreeParser(reducer_tree, reducer_name);
  return function () {
    var state = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : initial_state;
    var action = arguments.length > 1 ? arguments[1] : undefined;
    action = isObject(action) ? action : {};
    var type = String(action.type);

    if (reducerHandlers.hasOwnProperty(type)) {
      var reducerHandler = reducerHandlers[type];
      return produce(state, function (draftState) {
        var returnedValue = reducerHandler(draftState, action);

        if (!isUndefined(returnedValue)) {
          return returnedValue;
        }
      });
    } else {
      return state;
    }
  };
};

module.exports = reducersCreator;