Added function getNextOccurrence, Bug fix isValidDate

CHANGELOG.md

@@ -1,5 +1,18 @@
 # @sgx4u/date-time-utils - Changelog
 
+## 2.3.0
+
+### Minor Release
+
+-   Added function - `getNextOccurrence`
+-   Bug fix in isValidDate where it should stop further checks when valid date is already confirmed
+
+## 2.2.1
+
+### Documentation
+
+-   Updated documentation
+
 ## 2.2.0
 
 ### Minor Release

README.md

@@ -38,6 +38,7 @@
 -   [`addSubtractTime`](https://github.com/sgx4u/sgx4u-date-time-utils/blob/production/src/add-subtract-time/add-subtract-time.md) ‐ Add/Subtract time value from a given time and get the new value in different formats
 -   [`isValidDate`](https://github.com/sgx4u/sgx4u-date-time-utils/blob/production/src/is-valid-date/is-valid-date.md) ‐ Check if the given date is valid or not
 -   [`isLeapYear`](https://github.com/sgx4u/sgx4u-date-time-utils/blob/production/src/is-leap-year/is-leap-year.md) ‐ Check if the given year is a leap year
+-   [`getNextOccurrence`](https://github.com/sgx4u/sgx4u-date-time-utils/blob/production/src/get-next-occurrence/get-next-occurrence.md) ‐ Find the next occurrence of the given day
 
 <br/>
 

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@sgx4u/date-time-utils",
-	"version": "2.2.1",
+	"version": "2.3.0",
 	"private": false,
 	"description": "A date-time utility library",
 	"keywords": [

src/get-next-occurrence/get-next-occurrence.md

@@ -0,0 +1,31 @@
+## `getNextOccurrence`
+
+Find the next occurrence of the given day.
+
+## Usage
+
+```tsx
+import { getNextOccurrence } from '@sgx4u/date-time-utils';
+
+const Demo = () => {
+	const nextSunday = getNextOccurrence('Sunday');
+	return <p>Next Sunday: {nextSunday}</p>;
+};
+```
+
+## Reference
+
+```ts
+getNextOccurrence(day, startDate): string;
+```
+
+### Props
+
+-   `day` The day to find the next occurrence of, `type`: 'Sunday' | 'Monday' | 'Tuesday' | 'Wednesday' | 'Thursday' | 'Friday' | 'Saturday'
+-   `startDate` The date to start checking from, `type`: Date | string | number, `optional`
+
+### Example
+
+-   `getNextOccurrence('Sunday')` - With no start date mentioned it will default to the current date, so lets say current date is 10th Jan 2025. Result - 'Sun, 12 Jan 2025 00:00:00 GMT'
+-   `getNextOccurrence('Sunday', '2025-01-20T00:00:00.000Z')` - 'Sun, 26 Jan 2025 00:00:00 GMT'
+-   `getNextOccurrence('Sunday', 'ABC')` - 'Invalid date'

src/get-next-occurrence/get-next-occurrence.test.ts

@@ -0,0 +1,30 @@
+import { describe, expect, test } from '@jest/globals';
+
+import { getNextOccurrence } from './get-next-occurrence';
+
+describe('getNextOccurrence utility function', () => {
+	// Test 1: Test for next occurrence of a weekday
+	test('Should return the correct next Monday from today', () => {
+		const today = new Date();
+		const result = getNextOccurrence('Monday');
+		expect(new Date(result).getTime()).toBeGreaterThan(today.getTime()); // Ensure it's a future date
+	});
+
+	// Test 2: Test with a specific start date
+	test('Should return the next occurrence of Sunday from a given date', () => {
+		const result = getNextOccurrence('Sunday', new Date('2025-02-10')); // Monday
+		expect(result).toBe('Sun, 16 Feb 2025 00:00:00 GMT');
+	});
+
+	// Test 3: Test if the function correctly rolls over to the next week
+	test('Should return the correct next Friday when today is Saturday', () => {
+		const result = getNextOccurrence('Monday', new Date('2025-02-28')); // Friday
+		expect(result).toBe('Mon, 03 Mar 2025 00:00:00 GMT');
+	});
+
+	// Test 4: Test for invalid date
+	test('Should return "Invalid date" for an invalid date', () => {
+		const result = getNextOccurrence('Monday', 'ABC');
+		expect(result).toBe('Invalid date');
+	});
+});

src/get-next-occurrence/get-next-occurrence.ts

@@ -0,0 +1,22 @@
+import { daysFull } from '../data/date.data';
+
+type DayType = 'Sunday' | 'Monday' | 'Tuesday' | 'Wednesday' | 'Thursday' | 'Friday' | 'Saturday';
+
+/**
+ * @function
+ * @description - Find the next occurrence of the given day.
+ * @param day - The day to find the next occurrence of; type: 'Sunday' | 'Monday' | 'Tuesday' | 'Wednesday' | 'Thursday' | 'Friday' | 'Saturday'
+ * @param startDate - The date to start checking from; type: Date | string | number; default: current date; optional
+ * @returns { string } Returns UTC value of the result date; type: string
+ */
+export const getNextOccurrence = (day: DayType, startDate: Date | string | number = new Date()): string => {
+	const date = new Date(startDate);
+	if (!(date instanceof Date) || isNaN(date.getTime())) return 'Invalid date';
+
+	const requiredDayIndex = daysFull.indexOf(day);
+	const currentDayIndex = date.getUTCDay();
+
+	const daysToAdd = requiredDayIndex - currentDayIndex + (requiredDayIndex < currentDayIndex ? 7 : 0);
+	date.setUTCDate(date.getUTCDate() + daysToAdd);
+	return date.toUTCString();
+};

src/index.ts

@@ -4,3 +4,4 @@ export * from './index-to-name/index-to-name';
 export * from './add-subtract-time/add-subtract-time';
 export * from './is-valid-date/is-valid-date';
 export * from './is-leap-year/is-leap-year';
+export * from './get-next-occurrence/get-next-occurrence';

src/is-valid-date/is-valid-date.ts

@@ -64,7 +64,7 @@ export const isValidDate = (date: unknown, format?: string): boolean => {
 		console.error(error);
 	}
 
-	if (!format || typeof date !== 'string') return isValid;
+	if (isValid || !format || typeof date !== 'string') return isValid;
 
 	// Check if the format and date separators are the same.
 	if (!checkIfAllSeparatorsAreValid(date, format)) return false;