我需要用Java语言编写的完整的图书管理系统单元测试源代码

好的，下面是一个用Java语言编写的完整的图书管理系统单元测试源代码，您可以参考一下：

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

public class LibraryTest {
    private Library library;
    private Book book;
    private User user;

    @BeforeEach
    public void setUp() {
        library = new Library();
        book = new Book("123456", "The Lord of the Rings", "J.R.R. Tolkien", "Fantasy");
        user = new User("001", "John Smith");
    }

    @Test
    public void testAddBook() {
        library.addBook(book);
        Assertions.assertEquals(library.getBooks().get("123456"), book);
    }

    @Test
    public void testRemoveBook() {
        library.addBook(book);
        library.removeBook("123456");
        Assertions.assertEquals(library.getBooks().size(), 0);
    }

    @Test
    public void testRegisterUser() {
        library.registerUser(user);
        Assertions.assertEquals(library.getUsers().get("001"), user);
    }

    @Test
    public void testUnregisterUser() {
        library.registerUser(user);
        library.unregisterUser("001");
        Assertions.assertEquals(library.getUsers().size(), 0);
    }

    @Test
    public void testCheckOutBook() {
        library.addBook(book);
        library.registerUser(user);
        library.checkOutBook("123456", "001");
        Assertions.assertTrue(book.isCheckedOut());
        Assertions.assertEquals(user.getBorrowedBooks(), "123456");
    }

    @Test
    public void testCheckInBook() {
        library.addBook(book);
        library.registerUser(user);
        library.checkOutBook("123456", "001");
        library.checkInBook("123456", "001");
        Assertions.assertFalse(book.isCheckedOut());
        Assertions.assertEquals(user.getBorrowedBooks(), "");
    }

    @Test
    public void testBookInfo() {
        Assertions.assertEquals(book.bookInfo(), "123456 - The Lord of the Rings by J.R.R. Tolkien (Genre: Fantasy)");
    }

    @Test
    public void testUserInfo() {
        Assertions.assertEquals(user.userInfo(), "001 - John Smith");
    }

    @Test
    public void testBorrowBook() {
        user.borrowBook("123456");
        Assertions.assertEquals(user.getBorrowedBooks(), "123456");
    }

    @Test
    public void testReturnBook() {
        user.borrowBook("123456");
        user.returnBook("123456");
        Assertions.assertEquals(user.getBorrowedBooks(), "");
    }
}

上述代码是一个基于 JUnit 5 的单元测试框架，包括了对于 Book、User 和 Library 三个类的测试用例。您可以根据需要进行修改和完善，例如添加更多的测试用例，或者对于具体的项目进行适当的调整。