import { replaceUndefinedValuesWithNull } from './replaceUndefinedValuesWithNull';

describe('replaceUndefinedValuesWithNull', () => {
  it('should replace all undefined values with null', () => {
    const obj = {
      a: undefined,
      b: {
        c: undefined,
        d: 'hello'
      },
      e: null
    };

    const expected = {
      a: null,
      b: {
        c: null,
        d: 'hello'
      },
      e: null
    };

    const result = replaceUndefinedValuesWithNull(obj);
    expect(result).toEqual(expected);
  });

  it('should not modify objects with no undefined values', () => {
    const obj = {
      a: 1,
      b: {
        c: 2,
        d: 'hello'
      },
      e: null
    };

    const expected = {
      a: 1,
      b: {
        c: 2,
        d: 'hello'
      },
      e: null
    };

    const result = replaceUndefinedValuesWithNull(obj);
    expect(result).toEqual(expected);
  });

  it('should handle empty objects', () => {
    const obj = {};

    const expected = {};

    const result = replaceUndefinedValuesWithNull(obj);
    expect(result).toEqual(expected);
  });
});