diff --git a/Review b/Review
new file mode 100644
index 00000000..e69de29b
diff --git a/What b/What
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index 00000000..e69de29b
diff --git a/samples/book-app-project/README.md b/samples/book-app-project/README.md
index d3dd580a..8b401d70 100644
--- a/samples/book-app-project/README.md
+++ b/samples/book-app-project/README.md
@@ -30,6 +30,7 @@ It can add, remove, and list books. Also mark them as read.
 ```bash
 python book_app.py list
 python book_app.py add
+python book_app.py read
 python book_app.py find
 python book_app.py remove
 python book_app.py help
diff --git a/samples/book-app-project/book_app.py b/samples/book-app-project/book_app.py
index f0100c2d..a94ae998 100644
--- a/samples/book-app-project/book_app.py
+++ b/samples/book-app-project/book_app.py
@@ -59,6 +59,18 @@ def handle_find():
     show_books(books)
 
 
+def handle_read():
+    print("\nMark a Book as Read\n")
+
+    title = input("Enter the title of the book to mark as read: ").strip()
+    result = collection.mark_as_read(title)
+
+    if result:
+        print("\nBook marked as read.\n")
+    else:
+        print("\nBook not found.\n")
+
+
 def show_help():
     print("""
 Book Collection Helper
@@ -66,6 +78,7 @@ def show_help():
 Commands:
   list     - Show all books
   add      - Add a new book
+  read     - Mark a book as read
   remove   - Remove a book by title
   find     - Find books by author
   help     - Show this help message
@@ -83,6 +96,8 @@ def main():
         handle_list()
     elif command == "add":
         handle_add()
+    elif command == "read":
+        handle_read()
     elif command == "remove":
         handle_remove()
     elif command == "find":
diff --git a/samples/book-app-project/tests/test_books.py b/samples/book-app-project/tests/test_books.py
index 061149c5..b898247c 100644
--- a/samples/book-app-project/tests/test_books.py
+++ b/samples/book-app-project/tests/test_books.py
@@ -1,5 +1,6 @@
 import sys
 import os
+import importlib
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
 import pytest
@@ -51,3 +52,31 @@ def test_remove_book_invalid():
     collection = BookCollection()
     result = collection.remove_book("Nonexistent Book")
     assert result is False
+
+
+def test_read_command_marks_book_as_read(monkeypatch, capsys):
+    book_app = importlib.import_module("book_app")
+    monkeypatch.setattr(book_app, "collection", BookCollection())
+    book_app.collection.add_book("Dune", "Frank Herbert", 1965)
+
+    monkeypatch.setattr("builtins.input", lambda _prompt: "Dune")
+    monkeypatch.setattr(sys, "argv", ["book_app.py", "read"])
+
+    book_app.main()
+
+    captured = capsys.readouterr()
+    assert "Book marked as read." in captured.out
+    assert book_app.collection.find_book_by_title("Dune").read is True
+
+
+def test_read_command_book_not_found(monkeypatch, capsys):
+    book_app = importlib.import_module("book_app")
+    monkeypatch.setattr(book_app, "collection", BookCollection())
+
+    monkeypatch.setattr("builtins.input", lambda _prompt: "Missing Book")
+    monkeypatch.setattr(sys, "argv", ["book_app.py", "read"])
+
+    book_app.main()
+
+    captured = capsys.readouterr()
+    assert "Book not found." in captured.out
diff --git a/samples/book-app-project/tests/test_utils.py b/samples/book-app-project/tests/test_utils.py
new file mode 100644
index 00000000..ba749f85
--- /dev/null
+++ b/samples/book-app-project/tests/test_utils.py
@@ -0,0 +1,28 @@
+import os
+import sys
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from utils import get_user_choice
+
+
+def test_get_user_choice_rejects_empty_input(monkeypatch, capsys):
+    responses = iter(["", "2"])
+    monkeypatch.setattr("builtins.input", lambda _prompt: next(responses))
+
+    choice = get_user_choice()
+
+    captured = capsys.readouterr()
+    assert "Input cannot be empty" in captured.out
+    assert choice == "2"
+
+
+def test_get_user_choice_rejects_non_numeric_input(monkeypatch, capsys):
+    responses = iter(["abc", "4"])
+    monkeypatch.setattr("builtins.input", lambda _prompt: next(responses))
+
+    choice = get_user_choice()
+
+    captured = capsys.readouterr()
+    assert "Invalid input. Please enter a number." in captured.out
+    assert choice == "4"
diff --git a/samples/book-app-project/utils.py b/samples/book-app-project/utils.py
index 4151dcda..321810db 100644
--- a/samples/book-app-project/utils.py
+++ b/samples/book-app-project/utils.py
@@ -8,10 +8,31 @@ def print_menu():
 
 
 def get_user_choice() -> str:
-    return input("Choose an option (1-5): ").strip()
+    while True:
+        choice = input("Choose an option (1-5): ").strip()
+        if not choice:
+            print("Input cannot be empty. Please enter a number.")
+            continue
+        if not choice.isdigit():
+            print("Invalid input. Please enter a number.")
+            continue
+        return choice
 
 
 def get_book_details():
+    """Collect book details from user input.
+
+    Parameters:
+        None: This function does not accept parameters. It reads values from
+            standard input prompts.
+
+    Returns:
+        tuple[str, str, int]: A 3-item tuple containing:
+            - title (str): The entered book title (whitespace-trimmed).
+            - author (str): The entered author name (whitespace-trimmed).
+            - year (int): The publication year parsed as an integer. If the
+              year input is invalid, this value defaults to 0.
+    """
     title = input("Enter book title: ").strip()
     author = input("Enter author: ").strip()
 
diff --git a/what b/what
new file mode 100644
index 00000000..e69de29b