@breautek/merge-change/test/utils.diff.spec.js

Simple library for deep merge of objects and other types (also for patch and immutable updates). Declarative operations to specific merge, for example to remove properties. Customize merging between specific types. Calculating diffs.

const mc = require('../index.js');
const {utils, methods} = mc;

class Custom {
  constructor(value = {}) {
    this.value = value;
  }

  [methods.toFlat]() {
    return this.value;
  }

  toJSON() {
    return this.value;
  }
}

describe('Test diff()', () => {

  test('common', () => {

    let first = {
      name: 1,
      profile: {
        surname: 'x',
        avatar: {
          code: 1,
          url: 'xxx',
          list: [
            {a: 0},
            1,
            null,
          ],
          i18n: new Custom({x: undefined, ru: 'RU', en: 'EN'}),
        },
      },
      date: new Date('2021-01-26T23:41:59.433Z'),
      parent: {_id: 'null'},
      i18n: new Custom({ru: 'RU', en: 'EN'}),
      some: 1,
      someDeep: {
        deep: {
          superdeep: [200],
        },
      },
    };

    let second = {
      name: 2,
      profile: {
        surname2: 'x',
        avatar: {
          code: 1,
          url: 'xxx',
          list: [0, 1, 2],
          i18n: new Custom({x: undefined, ru: 'GB', en: 'EN'}),
        },
      },
      date: new Date('2021-01-26T23:41:59.433Z'),
      parent: {_id: 'null'},
      i18n: new Custom({ru: 'RU', en: 'EN'}),
      newV: {
        some: {
          dd: 100,
          x: {
            gg: 200,
          },
        },
      },
    };

    const diff = utils.diff(first, second, {});

    expect(utils.plain(diff)).toEqual({
      $set: {
        'name': 2,
        'profile.surname2': 'x',
        'profile.avatar.list': [0, 1, 2],
        'profile.avatar.i18n.ru': 'GB',
        'date': '2021-01-26T23:41:59.433Z',
        'newV': {
          'some': {
            'dd': 100,
            'x': {
              'gg': 200,
            },
          },
        },
      },
      $unset: [
        'profile.surname',
        'some',
        'someDeep',
      ],
    });

    // Merge first object with diff
    const updated = mc.merge(utils.plain(first), diff);

    expect(utils.plain(updated)).toEqual(utils.plain(second));
  });


  test('with ignore', () => {

    let first = {
      name: 1,
      profile: {
        surname: 'x',
        avatar: {
          code: 1,
        },
      },
      someDeep: {
        deep: {
          superdeep: [200],
        },
      },
    };

    let second = {
      name: 2,
      profile: {
        newSurname: 'x',
        avatar: {
          code: 1,
          url: 'xxx',
        },
      }
    };

    const diff = utils.diff(first, second, {ignore: ['someDeep', 'profile.avatar.url']});

    expect(utils.plain(diff)).toEqual({
      $set: {
        "name": 2,
        "profile.newSurname": "x",
        //"profile.avatar.url": "xxx"
      },
      $unset: [
        "profile.surname",
        //"someDeep"
      ]
    });
  });

  test('with white', () => {

    let first = {
      name: 1,
      profile: {
        surname: 'x',
        avatar: {
          code: 1,
        },
      },
      someDeep: {
        deep: {
          superdeep: [200],
        },
      },
    };

    let second = {
      name: 2,
      profile: {
        newSurname: 'x',
        avatar: {
          code: 1,
          url: 'xxx',
        },
      }
    };

    const diff = utils.diff(first, second, {white: ["name", "profile", "profile.newSurname", "profile.surname"]});

    console.log(diff);

    expect(utils.plain(diff)).toEqual({
      $set: {
        "name": 2,
        "profile.newSurname": "x",
        //"profile.avatar.url": "xxx"
      },
      $unset: [
        "profile.surname",
        //"someDeep"
      ]
    });
  });


  test('simple', () => {
    const first = {
      name: 'value',
      profile: {
        surname: 'Surname',
        birthday: new Date(),
        avatar: {
          url: 'pic.png'
        }
      },
      access: [100, 350, 200]
    }

    const second = {
      login: 'value',
      profile: {
        surname: 'Surname2',
        avatar: {
          url: 'new/pic.png'
        }
      },
      access: [700]
    }

    const diff = utils.diff(first, second, {separator: '.'});

    expect(diff).toEqual({
      $set: {
        'login': 'value',
        'profile.surname': 'Surname2',
        'profile.avatar.url': 'new/pic.png',
        'access': [700]
      },
      $unset: [
        'profile.birthday',
        'name'
      ]
    });
  });


  test('custom compare', () => {
    const first = {
      number: '10',
      text: '10',
      double: 0.3,
      double2: 12.12345
    }

    const second = {
      number: 10,
      text: 'ten',
      double: 0.1 + 0.2,
      double2: 12.12346
    }

    const diff = utils.diff(first, second, {
      equal: (first, second) => {
        if (first === second) return true;
        first = Number(first);
        second = Number(second);
        if (first !== null && second !== null) {
          return first === second || Math.abs(first - second) < Number.EPSILON
        }
        return false;
      }
    });

    expect(diff).toEqual({
      $set: {
        double2: 12.12346,
        text: 'ten',
      },
      $unset: []
    });
  });
});