Часть 5 — Написание тестов

• Все фукции вашего класса должны быть покрыты тестами.

• Использовать фикстуры для инициализации начального состояния объекта.

• Итого, должно быть несколько тестовых классов, в каждом из которых целе-

вая структура данных создается в фикстуре в некотором инициализированном

состоянии (пустая, заполненная и тд), а после очищается.

• Написать тестовый набор, запускающий все тесты.

Структура проекта:

Код программы:

package queue;

/**

* The < tt> Queue< /tt> class represents a first-in-first-out (FIFO) queue of

* generic items. It supports the usual < em> enqueue< /em> and < em> dequeue< /em>

* operations, along with methods for peeking at the top item, testing if the

* queue is empty, and iterating through the items in FIFO order.

*/

public class Queue< Item> {

private int N; // number of elements on queue

private Node first; // beginning of queue

private Node last; // end of queue

// helper linked list class

private class Node {

private Item item;

private Node next;

}

/**

* Create an empty queue.

*/

public Queue() {

first = null;

last = null;

N = 0;

assert check();

}

/**

* Is the queue empty?

*/

public boolean isEmpty() {

boolean isEmpt=false;

if(first==null || last==null){

isEmpt=true;

}

return isEmpt;

}

/**

* Return the number of items in the queue.

*/

public int size() {

return N;

}

/**

* Return the item least recently added to the queue.

*

* @throws java.util.NoSuchElementException if queue is empty.

*/

public Item peek()throws NullPointerException{

// FIXME throw exception if queue is Empty.+

// TODO implement method+

if(first==null){

throw new NullPointerException(" Queue is empty");

}

return last.item;

}

/**

* Add the item to the queue.

*/

public void enqueue(Item item)throws NullPointerException {

if(item==null){

throw new NullPointerException(" Item velue null");

}

Node oldfirst = first;

first = new Node();

first.item = item;

first.next = oldfirst;

++N;

if (isEmpty()) {

last = first;

}else{

last.next=null;

}

assert check();

}

/**

* Remove and return the item on the queue least recently added.

*

* @throws java.util.NoSuchElementException if queue is empty.

*/

public Item dequeue(){

// FIXME throw exception if queue is Empty.+

if(N==1) {

Item lastItem = first.item;

first = null;

last = null;

--N;

return lastItem;

}else if(N==0){

throw new NullPointerException(" Queue is empty");

}else{

Item item = last.item;

for (Node x = first; x.next! = null; x=x.next) {

if(x.next.next==null){

last=x;

last.next=null;

break;

}

}

--N;

if (isEmpty()) {

last = null; // to avoid loitering

}

assert check();

return item;

}

}

/**

* Return string representation.

*/

public String toString() {

StringBuilder s = new StringBuilder();

for (Node x = first; x == null; x = x.next) {

s.append(x.item + " ");

}

return s.toString();

}

// check internal invariants

private boolean check() {

if (N == 0) {

if (first! = null) {

return false;

}

if (last! = null) {

return false;

}

} else if (N == 1) {

if (first == null || last == null) {

return false;

}

if (first! = last) {

return false;

}

if (first.next! = null) {

return false;

}

} else {

if (first == last) {

return false;

}

if (first.next == null) {

return false;

}

if (last.next! = null) {

return false;

}

// check internal consistency of instance variable N

int numberOfNodes = 0;

for (Node x = first; x! = null; x = x.next) {

numberOfNodes++;

}

if (numberOfNodes! = N) {

return false;

}

// check internal consistency of instance variable last

Node lastNode = first;

while (lastNode.next! = null) {

lastNode = lastNode.next;

}

if (last! = lastNode) {

return false;

}

}

return true;

}

}

package queue;

import java.util.Scanner;

public class QueueClient {

/**

* A test client.

*/

public static void main(String[] args) {

Queue< String> q = new Queue< String> ();

Scanner scanner = new Scanner(System.in);

while (scanner.hasNext()) {

String item = scanner.next();

if(item.equals(" peek")){

System.out.println(" head queue: " +q.peek());

}else{

if(item.equals(" cancel")){

break;

}else{

if (! item.equals(" -")) {

q.enqueue(item);

} else if (! q.isEmpty()) {

System.out.println(q.dequeue() + " ");

}

}

}

}

System.out.println(q.size());

}

}

package queue;

import org.junit.runner.RunWith;

import org.junit.runners.Suite;

/**

* Created by piratXus on 02.11.2016.

*/

@RunWith(Suite.class)

@Suite.SuiteClasses({

QueueEmptiTest.class,

QueueTest.class

})

public class QueueMainTest {

}

package queue;

import org.junit.Test;

/**

* Created by piratXus on 02.11.2016.

*/

public class QueueEmptiTest {

Queue< String> queue=new Queue< > ();

@Test(expected = NullPointerException.class)

public void enqueueTest(){

System.out.println(" enqueue null pointer exception test");

queue.enqueue(null);

}

@Test(expected = NullPointerException.class)

public void peekTest(){

System.out.println(" peek null pointer exception test");

queue.peek();

}

@Test(expected = NullPointerException.class)

public void dequeueTest(){

System.out.println(" dequeue null pointer exception test");

queue.dequeue();

}

}

package queue;

import org.junit.After;

import org.junit.Before;

import org.junit.Test;

import static junit.framework.Assert.assertEquals;

import static org.junit.Assert.assertFalse;

public class QueueTest{

Queue< String> queue=new Queue< String> ();

@Before

public void setQueueBeforTest(){

queue.enqueue(" 1");

queue.enqueue(" 2");

queue.enqueue(" 3");

queue.enqueue(" 4");

queue.enqueue(" 5");

}

@After

public void deleteQueueAfterTest(){

queue=null;

}

@Test

public void isEmptyTest(){

System.out.println(" Is EmptyTest");

assertFalse(queue.isEmpty());

System.out.println(" true");

}

@Test

public void sizeTest(){

System.out.println(" Is Size Test");

assertEquals(5, queue.size());

System.out.println(" true");

}

@Test

public void peekTest() {

System.out.println(" Is peek Test");

assertEquals(" 1", queue.peek());

System.out.println(" true");

}

@Test(expected = NullPointerException.class)

public void dequeueTest(){

System.out.println(" Is dequeue Test");

assertEquals(" 1", queue.dequeue());

assertEquals(" 2", queue.dequeue());

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

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

assertEquals(" 5", queue.dequeue());

queue.dequeue();

System.out.println(" true");

}

}