isValidDate

1/**
2 * Checks if a value is a valid Date object.
3 *
4 * @param value - The value to check.
5 * @returns True if the value is a Date and represents a valid date.
6 */
7export function isValidDate(value: any): boolean {
8  return value instanceof Date && !isNaN(value.getTime());
9}

• Accurate Date Validation

  Confirms that the value is a Date instance and represents a valid date (not Invalid Date).

• Safe Type Checking

  Uses instanceof Date to ensure the value is genuinely a Date object, avoiding false positives from strings or numbers.

• Handles Edge Cases

  Rejects malformed or NaN-based dates that technically pass as Date objects but are invalid.

• Lightweight and Reliable

  Compact logic with no dependencies makes it ideal for frequent use in validations and type guards.

Tests | Examples

1test('isValidDate - valid date', () => {
2  expect(isValidDate(new Date())).toBe(true);
3});
4
5test('isValidDate - invalid date', () => {
6  expect(isValidDate(new Date('invalid'))).toBe(false);
7});
8
9test('isValidDate - string instead of Date', () => {
10  expect(isValidDate('2023-01-01')).toBe(false);
11});
12
13test('isValidDate - number instead of Date', () => {
14  expect(isValidDate(Date.now())).toBe(false);
15});
16
17test('isValidDate - null and undefined', () => {
18  expect(isValidDate(null)).toBe(false);
19  expect(isValidDate(undefined)).toBe(false);
20});
21
22test('isValidDate - plain object', () => {
23  expect(isValidDate({})).toBe(false);
24});

Common Use Cases

• Form Input Validation

  Validate date fields from user input or forms before processing or submitting.

• Data Parsing and Importing

  Ensure date values parsed from CSV, JSON, or external sources are valid before use.

• API Payload Validation

  Check incoming date fields in API requests to prevent runtime errors or invalid database entries.

• Conditional Logic Based on Time

  Guard time-sensitive logic (e.g., scheduling, expiration) with reliable date validation.

• Testing and Assertion Utilities

  Confirm that test results or mock data contain valid date values when asserting correctness.