Increase test coverage (fixes #3895 #3896) (#3897)

src/test/java/com/thealgorithms/maths/LongDivisionTest.java

@@ -5,21 +5,51 @@ import org.junit.jupiter.api.Test;
 import static org.junit.jupiter.api.Assertions.*;
 
 public class LongDivisionTest {
-	
+
+    // Requirement: Dividend (positive) is  greater than divisor (positive), returns correct integer after division
     @Test
     void testOne() {
         assertEquals(3, LongDivision.divide(10,3));
     }
-  
-      @Test
+
+    // Requirement: Dividend (positive) is  greater than divisor (negative), returns correct integer after division
+    @Test
     void testTwo() {
         assertEquals(-2, LongDivision.divide(7,-3));
     }
   
-  
-      @Test
+    // Requirement: Dividend (positive) is  greater than divisor (negative), returns correct integer after division
+    // Basically the same as in the first test
+    @Test
     void testThree() {
         assertEquals(10, LongDivision.divide(105,10));
     }
+
+    // Requirement: Dividend (negative), divisor (positive), returns correct integer after division
+    // Tests the case where the dividend is less than 0.
+    @Test
+    void testNegativeDividend() {
+        assertEquals(-1, LongDivision.divide(-5,3));
+    }
 	
+    // Requirement: Dividend (positive), divisor (positive), returns correct integer after division
+    // Tests the case where the dividend is less than the divisor. The test should return 0 in this case. 
+    @Test
+    void testDividendLessThanDivisor() {
+        assertEquals(0, LongDivision.divide(3,5));
+    }
+
+    // Requirement: Dividend (neither), divisor (positive), returns correct integer after division
+    // Tests the case where the dividend is 0. This should return a 0.
+    @Test
+    void testDividendIsZero() {
+        assertEquals(0, LongDivision.divide(0,5));
+    }
+
+    // Requirement: Dividend (positive), divisor (neither), returns correct integer after division
+    // Tests the case where the divisor is 0. This should return a 0.
+    @Test
+    void testDivisionByZero() {
+        assertEquals(0, LongDivision.divide(5,0));  
+    }
 }