LinkedQueueTest.java

package com.examplehub.datastructures.queue;

import static org.junit.jupiter.api.Assertions.*;

import org.junit.jupiter.api.Test;

class LinkedQueueTest {
  @Test
  void testQueue() throws IllegalAccessException {
    LinkedQueue<String> queue = new LinkedQueue<>();
    assertTrue(queue.empty());
    assertEquals(0, queue.size());
    assertEquals("", queue.toString());

    for (int i = 1; i <= 5; ++i) {
      queue.enqueue(i + "");
    }
    assertEquals(5, queue.size());
    assertEquals("1 <- 2 <- 3 <- 4 <- 5", queue.toString());

    assertEquals("1", queue.dequeue());
    assertEquals("2", queue.dequeue());
    assertEquals("3 <- 4 <- 5", queue.toString());

    assertTrue(queue.enqueue("1"));
    assertTrue(queue.enqueue("2"));
    assertEquals("3 <- 4 <- 5 <- 1 <- 2", queue.toString());

    assertEquals("3", queue.dequeue());
    assertEquals("4", queue.dequeue());

    queue.clear();
    assertEquals(queue.size(), 0);
    assertTrue(queue.empty());
    assertEquals("", queue.toString());
  }
}