测试 | Mock object

实例：

　　

一个简单的图书管理系统包括三个类：

1. Book提供了书籍的定义
2. BookService提供了有关书籍借阅和归还的服务
3. BookMananger查找书籍并把对书籍状态的更改更新到数据库中

目前，Book类和Bookservice类都已完成，但BookManager只是一个接口，对它的实现还没有完成。

目标： 对BookService类中的borrowBook和returnBook两个方法进行单元测试的代码，要求使用EasyMock模拟BookManager对象。

package org.demo.test.library;

public class Book {
	private String name;
	private String isbn; //书号
	private double price;
	private boolean inShell; // 是否在架上

	public Book(){}
	public Book(String name, String isbn, double price,
			boolean inShell){
		this.name = name;
		this.isbn = isbn;
		this.price = price;
		this.inShell = inShell;
	}

	/**
	* get set方法省略
        **/
	public boolean isInShell(){
		return this.inShell;
	}
	public void setInShell(boolean inShell){
		this.inShell = inShell;
	}

}

　　

package org.demo.test.library;

public class BookService {
	private BookManager bookManager;

	public BookService(BookManager bookManager){
		this.bookManager = bookManager;
	}

	public boolean borrowBook (String isbn){
		Book book = bookManager.findBook(isbn);
		if (book != null && book.isInShell()){
			//修改shell值
			book.setInShell(false);
			bookManager.updateBook(book);
			return true;
		}
		return false;
	}
	public boolean returnBook (String isbn){
		Book book = bookManager.findBook(isbn);
		if (book != null && !book.isInShell()){
			book.setInShell(true);
			return true;
		}
		return false;
	}

}

　　

package org.demo.test.library;

public interface BookManager {
	Book findBook(String isbn); // 根据isbn在数据库中找到相应的书籍
	void updateBook(Book book); // 更新数据库中书籍的状态
}

　　

package org.demo.test.library;

import static org.easymock.EasyMock.createMock;
import static org.easymock.EasyMock.expect;
import static org.easymock.EasyMock.replay;
import static org.junit.Assert.*;

import org.demo.test.account.AccountManager;
import org.junit.Before;
import org.junit.Test;
import org.junit.rules.ExpectedException;

public class BookServiceTest {

	private BookManager bookManager;
	private BookService bookService;

	@Before
	public void setUp() throws Exception {
		bookManager = createMock("bookManager",BookManager.class);

		bookService = new BookService(bookManager);

	}

	@Test
	public void testBorrowBook() {
		Book book1 = new Book("Java","123",20.2,true);
		Book book2 = new Book("Web","124",20.9,false);
		Book book3 = new Book("JavaScript","125",20.9,false);

		bookManager.updateBook(book1);
		bookManager.updateBook(book2);

		/**
		 * 定义查询接口返回值
		 */
		expect(bookManager.findBook("123")).andReturn(book1);
		expect(bookManager.findBook("124")).andReturn(book2);
		expect(bookManager.findBook("126")).andReturn(null);

		/**
		 *
		 */
		replay(bookManager);

		/**
		 * 执行测试
		 */
		bookService.borrowBook("123");
		bookService.borrowBook("124");
		bookService.borrowBook("126");

		assertEquals(false, book1.isInShell());
		assertEquals(false, book2.isInShell());
	}

	@Test
	public void testReturnBook() {
		Book book1 = new Book("Java","123",20.2,true);
		Book book2 = new Book("Web","124",20.9,false);

		bookManager.updateBook(book1);
		bookManager.updateBook(book2);

		expect(bookManager.findBook("123")).andReturn(book1);
		expect(bookManager.findBook("124")).andReturn(book2);
		expect(bookManager.findBook("126")).andReturn(null);

		replay(bookManager);

		bookService.returnBook("123");
		bookService.returnBook("124");
		bookService.returnBook("126");

		assertEquals(true, book1.isInShell());
		assertEquals(true, book2.isInShell());

	}
}