Testing and Integration

Part of the Object Oriented Programming section of Coddy's Python journey — lesson 60 of 64.

Challenge

Medium

In this challenge, you'll implement a multi-file library system with comprehensive test coverage. You'll work with three read-only files and one editable file that contains detailed TODO comments guiding your implementation:

book.py - Contains the Book class definition
user.py - Contains the User class you need to implement
library.py - Contains the Library class definition

Cheat sheet

This challenge involves implementing a multi-file library system with three main components:

book.py - Book class definition
user.py - User class implementation
library.py - Library class definition

The implementation should include comprehensive test coverage and follow the TODO comments provided in each file.

Try it yourself

from book import Book
from user import User
from library import Library

# Test case handler
test_case = input()

if test_case == "create_user":
    user_id = "1"
    name = "Name"
    
    user = User(user_id, name)
    print(user)
    print(f"Books borrowed: {len(user.books_borrowed)}")

elif test_case == "borrow_and_return_all":
    library = Library("Community Library")
    
    # Add books and users
    library.add_book(Book("The Great Gatsby", "F. Scott Fitzgerald", "123456"))
    library.add_book(Book("To Kill a Mockingbird", "Harper Lee", "789012"))
    library.add_book(Book("1984", "George Orwell", "345678"))
    
    user = User("U001", "Alice")
    library.add_user(user)
    
    # Borrow books
    library.borrow_book("123456", "U001")
    library.borrow_book("789012", "U001")
    library.borrow_book("345678", "U001")
    
    print(f"Books borrowed before: {len(user.books_borrowed)}")
    
    # Return all books
    num_returned = user.return_all_books(library)
    
    print(f"Books returned: {num_returned}")
    print(f"Books borrowed after: {len(user.books_borrowed)}")
    
    # Check if all books are available
    for book in library.books:
        print(f"Book {book.isbn} available: {book.available}")

elif test_case == "return_some_books":
    library = Library("Community Library")
    
    # Add books and users
    book1 = Book("The Great Gatsby", "F. Scott Fitzgerald", "123456")
    book2 = Book("To Kill a Mockingbird", "Harper Lee", "789012")
    library.add_book(book1)
    library.add_book(book2)
    
    user = User("U001", "Alice")
    library.add_user(user)
    
    # Borrow only one book
    library.borrow_book("123456", "U001")
    
    print(f"Books borrowed before: {len(user.books_borrowed)}")
    
    # Return all books
    num_returned = user.return_all_books(library)
    
    print(f"Books returned: {num_returned}")
    print(f"Books borrowed after: {len(user.books_borrowed)}")

elif test_case == "empty_return":
    library = Library("Community Library")
    
    user = User("U001", "Alice")
    library.add_user(user)
    
    print(f"Books borrowed: {len(user.books_borrowed)}")
    
    # Return all books (should be 0)
    num_returned = user.return_all_books(library)
    
    print(f"Books returned: {num_returned}")

elif test_case == "multiple_users":
    library = Library("Community Library")
    
    # Add books
    library.add_book(Book("The Great Gatsby", "F. Scott Fitzgerald", "123456"))
    library.add_book(Book("To Kill a Mockingbird", "Harper Lee", "789012"))
    
    # Add users
    user1 = User("U001", "Alice")
    user2 = User("U002", "Bob")
    library.add_user(user1)
    library.add_user(user2)
    
    # Borrow books
    library.borrow_book("123456", "U001")
    library.borrow_book("789012", "U002")
    
    print(user1)
    print(user2)
    
    # Return all books for user1
    num_returned = user1.return_all_books(library)
    
    print(f"Books returned by {user1.name}: {num_returned}")
    
    print(user1)
    print(user2)

elif test_case == "error_handling":
    library = Library("Community Library")
    
    # Add book and user
    library.add_book(Book("The Great Gatsby", "F. Scott Fitzgerald", "123456"))
    user = User("U001", "Alice")
    library.add_user(user)
    
    # Try to borrow non-existent book
    result = library.borrow_book("999999", "U001")
    print(result)
    
    # Try to borrow for non-existent user
    result = library.borrow_book("123456", "U999")
    print(result)
    
    # Borrow existing book
    result = library.borrow_book("123456", "U001")
    print(result)
    
    # Try to borrow same book again
    result = library.borrow_book("123456", "U001")
    print(result)
    
    # Try to return a book that wasn't borrowed
    result = library.return_book("789012", "U001")
    print(result)

elif test_case == "stress_test":
    library = Library("Community Library")
    
    user = User("U001", "Alice")
    library.add_user(user)
    
    # Add 100 books
    for i in range(1, 101):
        isbn = f"{i:03d}"  # Format as 001, 002, etc.
        library.add_book(Book(f"Book {i}", f"Author {i}", isbn))
        library.borrow_book(isbn, "U001")
    
    print(f"Books borrowed: {len(user.books_borrowed)}")
    
    # Return all books
    num_returned = user.return_all_books(library)
    
    print(f"Books returned: {num_returned}")
    print(f"Books borrowed after: {len(user.books_borrowed)}")