im-util.js

import Im from 'immutable';

export default class ImUtil {
  /*
   * new Map()
   */
   setEmptyMap = (obj, cursor) => {
     return obj.setIn(cursor, new Im.Map());
   }

  /*
   * new List()
   */
  addList = (obj, cursor, value) => {
    return obj.setIn(cursor, obj.getIn(cursor).push(value));
  }

  removeList = (obj, cursor, index) => {
    return obj.setIn(cursor, obj.getIn(cursor).remove(index));
  }

  setEmptyList = (obj, cursor) => {
    return obj.setIn(cursor, new Im.List());
  }

  /*
   * new Set()
   */
  setEmptySet = (obj, cursor) => {
   return obj.setIn(cursor, new Im.Set());
  }

  reverse = (obj, cursor) => {
    return obj.setIn(cursor, !obj.getIn(cursor));
  }

};

test.js

import ImUtil from '../lib/util/im-util';
import Im from 'immutable';
import expect from 'expect';

let imUtil = new ImUtil();

describe('Im', function() {
  it('imMap items sould clear', () => {
    let imMap = new Im.Map();
    imMap = imMap.setIn(['items', 'item'], 1);
    expect(Im.Map.isMap(imMap)).toEqual(true);
    expect(imMap.getIn(['items']).size).toEqual(1);
    const newImMap = imUtil.setEmptyMap(imMap, ['items']);
    expect(newImMap.getIn(['items']).size).toEqual(0);
  });

  it('imArray items sould add and remove', () => {
    const imMap = new Im.Map();
    const imArray = imMap.setIn(['items'], new Im.List());
    expect(Im.List.isList(imArray.getIn(['items']))).toEqual(true);
    const newImList = imUtil.addList(imArray, ['items'], 1);
    expect(newImList.getIn(['items', 0])).toEqual(1);
    const removeList = imUtil.removeList(newImList, ['items'], 0);
    expect(removeList.getIn(['items', 0])).toEqual(undefined);
    const clearList = imUtil.clearList(newImList, ['items']);
    expect(clearList.getIn(['items']).size).toEqual(0);
  })

  it('sould reverse the set', () => {
    const imMap = new Im.Map();
    let imArray = imMap.setIn(['items'], new Im.List());
    let newImList, revertImList;
    expect(Im.List.isList(imArray.getIn(['items']))).toEqual(true);
    [1,2,3,4,5,6].forEach((n, index) => {
      imArray = imUtil.addList(imArray, ['items'], false);
    })
    revertImList = imArray;
    [0,2,5].forEach((n) => {
      revertImList = imUtil.reverse(revertImList, ['items', n]);
    })
    expect(revertImList.getIn(['items', 0])).toEqual(true);
    expect(revertImList.getIn(['items', 2])).toEqual(true);
    expect(revertImList.getIn(['items', 5])).toEqual(true);
  })
});