added additional error handling

__test__/showTimeAgo.spec.js

@@ -34,8 +34,8 @@ test('showTimeAgo Utility should not be NaN', () => {
     expect(showTimeAgo(today)).not.toBeNaN();
 });
 
-test('showTimeAgo Utility should return null for no argument', () => {
-    expect(showTimeAgo()).toBeNull();
+test('showTimeAgo Utility should throw an error for no argument', () => {
+    expect(() => showTimeAgo()).toThrow('Invalid date parameter: dateParam cannot be empty. It must be a valid ISO date string or a Date object.');
 });
 
 test('showTimeAgo Utility type should be a function object', () => {
@@ -97,3 +97,24 @@ test('Test Date for multiple hours ago (less than a day)', () => {
     const hoursAgo = new Date(today.getTime() - 5 * 3600000); // 5 hours ago
     expect(showTimeAgo(hoursAgo)).toContain('hours ago');
 });
+
+// Additional test cases for error handling
+test('Test invalid date string', () => {
+    expect(() => showTimeAgo('invalid-date')).toThrow('Invalid date parameter: dateParam is not a valid ISO date string.');
+});
+
+test('Test null date', () => {
+    expect(() => showTimeAgo(null)).toThrow('Invalid date parameter: dateParam cannot be empty. It must be a valid ISO date string or a Date object.');
+});
+
+test('Test undefined date', () => {
+    expect(() => showTimeAgo(undefined)).toThrow('Invalid date parameter: dateParam cannot be empty. It must be a valid ISO date string or a Date object.');
+});
+
+test('Test array as date parameter', () => {
+    expect(() => showTimeAgo([])).toThrow('Invalid date parameter: dateParam must be a valid ISO date string or a Date object.');
+});
+
+test('Test object as date parameter', () => {
+    expect(() => showTimeAgo({})).toThrow('Invalid date parameter: dateParam must be a valid ISO date string or a Date object.');
+});

index.js

@@ -34,11 +34,27 @@ function showtimeago(dateParam) {
             return `${month} ${getOrdinalNum(day)}, ${year} at ${hours}:${minutes} ${ampm}`;
         }
 
+        // Validate the date parameter
+        function validateDateParam(dateParam) {
+            if (dateParam === undefined || dateParam === null) {
+                throw new Error("Invalid date parameter: dateParam cannot be empty. It must be a valid ISO date string or a Date object.");
+            }
+            if (typeof dateParam === 'string') {
+                const date = new Date(dateParam);
+                if (isNaN(date.getTime())) {
+                    throw new Error("Invalid date parameter: dateParam is not a valid ISO date string.");
+                }
+                return date;
+            }
+            if (typeof dateParam === 'object' && dateParam instanceof Date) {
+                return dateParam;
+            }
+            throw new Error("Invalid date parameter: dateParam must be a valid ISO date string or a Date object.");
+        }
+
         // Main function to calculate the "time ago" string
         function timeAgo(dateParam) {
-            if (!dateParam) return null;
-
-            const date = typeof dateParam === 'object' ? dateParam : new Date(dateParam);
+            const date = validateDateParam(dateParam);
             const now = new Date();
             const DAY_IN_MS = 86400000; // 24 * 60 * 60 * 1000
             const YEAR_IN_MS = 365.25 * DAY_IN_MS; // Account for leap years
@@ -92,7 +108,6 @@ function showtimeago(dateParam) {
             }
         }
 
-        // console.log(timeAgo(dateParam)) test
         return timeAgo(dateParam);
 
     } catch (error) {
@@ -101,5 +116,4 @@ function showtimeago(dateParam) {
     }
 }
 
-// showtimeago("2022-06-20T13:42:29-05:00")
 module.exports = showtimeago;

package.json

@@ -1,6 +1,6 @@
 {
   "name": "showtimeago",
-  "version": "4.0.1",
+  "version": "4.0.2",
   "description": "ShowTimeAgo is a utility that provides a human-readable format of how long ago a date was with zero configuration.",
   "main": "index.js",
   "scripts": {