test file for LowestSetBitTest added

Author: ishanki19-pixel

src/test/java/com/thealgorithms/bitmanipulation/LowestSetBitTest.java

@@ -0,0 +1,39 @@
+package com.thealgorithms.bitmanipulation;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+import com.thealgorithms.bitmanipulation.LowestSetBit;
+
+public class LowestSetBitTest {
+
+    LowestSetBit lowestSetBit = new LowestSetBit();
+
+    @Test
+    public void testIsolateLowestSetBit() {
+        // Test with positive number
+        assertEquals(1, lowestSetBit.isolateLowestSetBit(5));  // 5 in binary is 101, the lowest set bit is 1
+        assertEquals(2, lowestSetBit.isolateLowestSetBit(6));  // 6 in binary is 110, the lowest set bit is 2
+        assertEquals(4, lowestSetBit.isolateLowestSetBit(12)); // 12 in binary is 1100, the lowest set bit is 4
+
+        // Test with negative number
+        assertEquals(1, lowestSetBit.isolateLowestSetBit(-5)); // -5 in binary (two's complement) still has 1 as the lowest set bit
+        assertEquals(2, lowestSetBit.isolateLowestSetBit(-6)); // -6 in binary has 2 as the lowest set bit
+
+        // Test with zero
+        assertEquals(0, lowestSetBit.isolateLowestSetBit(0));  // Edge case: 0 should return 0
+    }
+
+    @Test
+    public void testClearLowestSetBit() {
+        // Test with positive number
+        assertEquals(4, lowestSetBit.clearLowestSetBit(5));  // 5 in binary is 101, clearing lowest set bit gives 100 (which is 4)
+        assertEquals(4, lowestSetBit.clearLowestSetBit(6));  // 6 in binary is 110, clearing lowest set bit gives 100 (which is 4)
+        assertEquals(8, lowestSetBit.clearLowestSetBit(12)); // 12 in binary is 1100, clearing lowest set bit gives 1000 (which is 8)
+
+        // Test with negative number
+        assertEquals(-6, lowestSetBit.clearLowestSetBit(-5)); // -5 in binary, clearing lowest set bit should give -6
+        assertEquals(-8, lowestSetBit.clearLowestSetBit(-6)); // -6 in binary, clearing lowest set bit should give -8
+
+        // Test with zero
+        assertEquals(0, lowestSetBit.clearLowestSetBit(0));   // Edge case: 0 should return 0
+    }
+}