Testing and Integration

Part of the Object Oriented Programming section of Coddy's GDScript journey. Lesson 61 of 65.

Challenge

Medium

Finish the system with returns, then let the tests run every part of it together. Keep everything you wrote in the previous steps; library.gd and user.gd change.

In Library, write return_book(isbn: String, user_id: String) -> String. Check in this order:

no book with that ISBN: return Book not found
no user with that id: return User not found
the book is available, or its borrower_id is another user: return This book was not borrowed by this user
otherwise make the book available again, set its borrower_id to "", remove the ISBN from the user's borrowed_isbns and return Book returned successfully

In User, write return_all_books(library: Library) -> int. It returns every book the user borrowed through library.return_book() and returns how many were returned. The user receives the library as an argument and does not store it, so no two objects point at each other.

The supplied code adds the commands return ISBN|ID and return_all ID. For this input:

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

the output is:

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

Your code goes in book.gd, user.gd and library.gd. main.gd holds the supplied input/output code and cannot be edited.

Try it yourself

extends Node

func _ready():
	# Supplied input/output code: keep it as it is
	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()