测试与集成

本课属于 Coddy GDScript 学习旅程的“面向对象编程”单元。第 61 课，共 65 课。

挑战

中等

完成系统的还书功能，然后让测试一起运行所有部分。保留你在前面步骤中写的所有内容；需要修改 library.gd 和 user.gd。

在 Library 中，编写 return_book(isbn: String, user_id: String) -> String。按以下顺序检查：

没有对应 ISBN 的图书：返回 Book not found
没有对应 ID 的用户：返回 User not found
图书已可借阅，或者它的 borrower_id 属于另一位用户：返回 This book was not borrowed by this user
否则，将图书重新设为可借阅，把它的 borrower_id 设为 ""，从用户的 borrowed_isbns 中移除该 ISBN，并返回 Book returned successfully

在 User 中，编写 return_all_books(library: Library) -> int。它会通过 library.return_book() 归还用户借阅的每本书，并返回归还的数量。用户通过参数接收图书馆对象，但不会保存它，因此这两个对象不会互相指向。

提供的代码添加了命令 return ISBN|ID 和 return_all ID。对于以下输入：

Community
book The Great Gatsby|F. Scott Fitzgerald|123456
book 1984|George Orwell|345678
user U001|Alice
user U002|Bob
borrow 123456|U001
borrow 345678|U001
return 123456|U002
return_all U001
users
stats

输出为：

Book borrowed successfully
Book borrowed successfully
This book was not borrowed by this user
Books returned by Alice: 2
User: Alice (ID: U001) - Books borrowed: 0
User: Bob (ID: U002) - Books borrowed: 0
Total Books: 2
Available Books: 2
Borrowed Books: 0
Total Users: 2
Users with Books: 0

你的代码要写在 book.gd、user.gd 和 library.gd 中。main.gd 包含提供的输入/输出代码，不能编辑。

亲手试试

extends Node

func _ready():
	# 提供的输入输出代码：保持原样
	var library := Library.new(OS.read_string_from_stdin())
	var line := OS.read_string_from_stdin()
	while line != "":
		var parts := line.split(" ", true, 1)
		var fields: PackedStringArray = parts[1].split("|") if parts.size() > 1 else PackedStringArray()
		match parts[0]:
			"book":
				library.add_book(Book.new(fields[0], fields[1], fields[2]))
			"user":
				library.add_user(User.new(fields[0], fields[1]))
			"borrow":
				print(library.borrow_book(fields[0], fields[1]))
			"return":
				print(library.return_book(fields[0], fields[1]))
			"return_all":
				var reader: User = library.find_user(fields[0])
				var count: int = reader.return_all_books(library)
				print("Books returned by ", reader.user_name, ": ", count)
			"search":
				var term: String = parts[1] if parts.size() > 1 else ""
				var found: Array = library.search_by_title(term)
				print("Results for '%s': %d" % [term, found.size()])
				for book in found:
					print("- ", book.title, " by ", book.author)
			"stats":
				var stats: Dictionary = library.get_statistics()
				print("Total Books: ", stats["total_books"])
				print("Available Books: ", stats["available_books"])
				print("Borrowed Books: ", stats["borrowed_books"])
				print("Total Users: ", stats["total_users"])
				print("Users with Books: ", stats["users_with_books"])
			"loans":
				var reader: User = library.find_user(fields[0])
				print(reader.user_name, " has borrowed:")
				for isbn in reader.borrowed_isbns:
					print("- ", library.find_book(isbn).title)
			"holder":
				var book: Book = library.find_book(fields[0])
				if book.available:
					print(book.title, " is on the shelf")
				else:
					print(book.title, " is borrowed by ", library.find_user(book.borrower_id).user_name)
			"books":
				for book in library.books:
					print(book)
			"users":
				for user in library.users:
					print(user)
			"show":
				print(library)
		line = OS.read_string_from_stdin()