@breautek/merge-change/test/$leave.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');

describe('Test $leave', () => {

  test('leave one prop (merge)', () => {
    const first = {
      f1: {a1: [1,2,3,4,5], a2: 11, a3: 12},
      f2: 10,
    };
    const second = {
      $leave: ['f1'],
    };
    const result = mc.merge(first, second);
    expect(result).toEqual({
      f1: {a1: [1,2,3,4,5], a2: 11, a3: 12},
    });
    // Check ref
    expect(result===first).toEqual(false);
    expect(result.f1===first.f1).toEqual(false);
    expect(result.f1.a1===first.f1.a1).toEqual(false);
  });

  test('leave two prop', () => {
    const first = {
      f1: {a1: 10, a2: 11, a3: 12},
      f2: 10,
      f3: 20
    };
    const second = {
      $leave: ['f1', 'f3'],
    };
    const result = mc.merge(first, second);
    expect(result).toEqual({
      f1: {a1: 10, a2: 11, a3: 12},
      f3: 20
    });
  });

  test('leave one and sub prop', () => {
    const first = {
      f1: {a1: 10, a2: 11, a3: 12},
      f2: 10,
      f3: 20
    };
    const second = {
      $leave: ['f2', 'f1.a1'],
    };
    const result = mc.merge(first, second);
    expect(result).toEqual({
      f1: {a1: 10},
      f2: 10,
    });
  });

  test('leave two elements', () => {
    const first = {
      f1: [1, 2, 3, 4, 5],
      f2: 10,
    };
    const second = {
      $leave: ['f1.0', 'f1.4'],
    };
    const result = mc.merge(first, second);
    expect(result).toEqual({
      f1: [1, 5],
    });
  });
});