Create ReverseQueueRecursionTest.java

Add ReverseQueueRecursionTest as required by CONTRIBUTING.md

Author: Vasundhara117

src/test/java/com/thealgorithms/datastructures/queues/ReverseQueueRecursionTest.java

@@ -0,0 +1,64 @@
+package com.thealgorithms.datastructures.queues;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.LinkedList;
+import java.util.Queue;
+
+import org.junit.jupiter.api.Test;
+
+class ReverseQueueRecursionTest {
+
+    @Test
+    void testReverseMultipleElements() {
+        Queue<Integer> queue = new LinkedList<>();
+        queue.add(1);
+        queue.add(2);
+        queue.add(3);
+        queue.add(4);
+
+        ReverseQueueRecursion.reverseQueue(queue);
+
+        assertEquals(4, queue.poll());
+        assertEquals(3, queue.poll());
+        assertEquals(2, queue.poll());
+        assertEquals(1, queue.poll());
+        assertTrue(queue.isEmpty());
+    }
+
+    @Test
+    void testReverseSingleElement() {
+        Queue<Integer> queue = new LinkedList<>();
+        queue.add(42);
+
+        ReverseQueueRecursion.reverseQueue(queue);
+
+        assertEquals(42, queue.poll());
+        assertTrue(queue.isEmpty());
+    }
+
+    @Test
+    void testReverseEmptyQueue() {
+        Queue<Integer> queue = new LinkedList<>();
+
+        ReverseQueueRecursion.reverseQueue(queue);
+
+        assertTrue(queue.isEmpty());
+    }
+
+    @Test
+    void testReverseStringQueue() {
+        Queue<String> queue = new LinkedList<>();
+        queue.add("A");
+        queue.add("B");
+        queue.add("C");
+
+        ReverseQueueRecursion.reverseQueue(queue);
+
+        assertEquals("C", queue.poll());
+        assertEquals("B", queue.poll());
+        assertEquals("A", queue.poll());
+        assertTrue(queue.isEmpty());
+    }
+}