isSame

1/**
2 * Compares two dates and returns whether they share the same year, month, and day.
3 *
4 * @param date1 - The first date.
5 * @param date2 - The second date.
6 * @returns An object with flags for year, month, and day equality.
7 */
8export function isSame(
9  date1: Date,
10  date2: Date
11): { isSameYear: boolean; isSameMonth: boolean; isSameDay: boolean } {
12  const isSameYear = date1.getFullYear() === date2.getFullYear();
13  const isSameMonth = isSameYear && date1.getMonth() === date2.getMonth();
14  const isSameDay = isSameMonth && date1.getDate() === date2.getDate();
15
16  return { isSameYear, isSameMonth, isSameDay };
17}

1test('isSame - full match (same day)', () => {
2  const a = new Date('2024-06-27');
3  const b = new Date('2024-06-27');
4  expect(isSame(a, b)).toEqual({
5    isSameYear: true,
6    isSameMonth: true,
7    isSameDay: true,
8  });
9});
10
11test('isSame - same year and month, different day', () => {
12  const a = new Date('2024-06-27');
13  const b = new Date('2024-06-25');
14  expect(isSame(a, b)).toEqual({
15    isSameYear: true,
16    isSameMonth: true,
17    isSameDay: false,
18  });
19});
20
21test('isSame - same year, different month', () => {
22  const a = new Date('2024-06-27');
23  const b = new Date('2024-05-27');
24  expect(isSame(a, b)).toEqual({
25    isSameYear: true,
26    isSameMonth: false,
27    isSameDay: false,
28  });
29});
30
31test('isSame - completely different', () => {
32  const a = new Date('2024-06-27');
33  const b = new Date('2023-05-15');
34  expect(isSame(a, b)).toEqual({
35    isSameYear: false,
36    isSameMonth: false,
37    isSameDay: false,
38  });
39});