isValidDate

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

• Accurate Validation

  Combines instanceof Date with !isNaN(getTime()) to ensure the value is both a Date object and holds a valid timestamp.

• Prevents Naive Type Checks

  Avoids false positives that might occur from just checking the object type, catching Invalid Date cases reliably.

• Lightweight and Efficient

  Performs minimal operations for validation, making it suitable for performance-sensitive code.

• Safe Type Guard

  Can act as a type guard in TypeScript, improving safety when working with dynamic input values.

Tests | Examples

1test('returns true for valid Date objects', () => {
2  expect(isValidDate(new Date())).toBe(true);
3  expect(isValidDate(new Date('2023-01-01'))).toBe(true);
4});
5
6test('returns false for invalid Date objects', () => {
7  expect(isValidDate(new Date('invalid date'))).toBe(false);
8});
9
10test('returns false for non-Date types', () => {
11  expect(isValidDate(Date.now())).toBe(false);
12  expect(isValidDate('2023-01-01')).toBe(false);
13  expect(isValidDate(null)).toBe(false);
14  expect(isValidDate(undefined)).toBe(false);
15  expect(isValidDate({})).toBe(false);
16});

Common Use Cases

• Parsing User Input

  Validate date values entered via forms or APIs to ensure they're not invalid or malformed.

• Sanity Checks in Date Calculations

  Prevent runtime errors by confirming inputs are valid dates before doing arithmetic or formatting.

• Data Validation in ETL Pipelines

  Clean or filter out invalid date entries when processing datasets.

• Form Validation and Feedback

  Provide user feedback if a selected or typed date is not recognized as valid.

• Preventing Logic Errors in Time-Based Logic

  Ensure that only valid date objects are used in comparisons, sorting, and scheduling functions.