Test: Write positive numbers test for factorial calculation

src/test/java/CalculationsTest.java

@@ -18,6 +18,19 @@ public class CalculationsTest {
 
         // Test with a large number
         assertEquals(1000000, calc.calculateSquare(1000));
+    }
+
+    @Test
+    public void testCalculateFactorial() {
+        Calculations fact = new Calculations();
+
+        // Test with positive numbers
+        assertEquals(1, fact.calculateFactorial(0));
+        assertEquals(1, fact.calculateFactorial(1));
+        assertEquals(2, fact.calculateFactorial(2));
+        assertEquals(6, fact.calculateFactorial(3));
+        assertEquals(24, fact.calculateFactorial(4));
+        assertEquals(120, fact.calculateFactorial(5));
 
     }
 }