FEATURE: Book Removal

Purpose

Allow a reader to remove a selected book from the reading list.

Trigger and Sequence

1. The reader submits the removal control for a listed book.
2. The application removes that book through the persistence boundary.
3. The application redirects or returns the reader to the ordered list.
4. The removed book is absent and remaining books retain their relative order.

Reads and Writes

• Reads the selected book identifier from the removal request.
• Writes deletion through book_store.remove.
• Reads the resulting list through ordered_book_listing.

Operational Behavior

The removal route is POST /books/<int:book_id>/remove. Unknown identifiers do not remove any other book.

Programmatic Acceptance

=== AC removal-route-reachable ===
Intent: The removal route accepts a valid removal request. from app import create_app

app = create_app({"TESTING": True}) client = app.test_client() title = "Book to Remove" author = "Removal Author" created = client.post("/books", data={"title": title, "author": author}) assert created.status_code in (200, 302, 303) listed = client.get("/") assert listed.status_code == 200 removed = client.post("/books/1/remove") assert removed.status_code in (200, 302, 303) === END AC removal-route-reachable ===

=== AC removal-persists ===
Intent: Removing a book makes it absent on the next public list read. from app import create_app

app = create_app({"TESTING": True}) client = app.test_client() title = "Temporary Book" author = "Temporary Author" client.post("/books", data={"title": title, "author": author}) before = client.get("/") assert before.status_code == 200 removed = client.post("/books/1/remove") assert removed.status_code in (200, 302, 303) after = client.get("/") assert after.status_code == 200 assert title.encode() not in after.data assert author.encode() not in after.data === END AC removal-persists ===

=== AC removal-preserves-remaining-order ===
Intent: Removing one book leaves the other books in their original relative order. from app import create_app

app = create_app({"TESTING": True}) client = app.test_client() first_title = "First Remaining" first_author = "First Author" removed_title = "Middle Removed" removed_author = "Middle Author" last_title = "Last Remaining" last_author = "Last Author" client.post("/books", data={"title": first_title, "author": first_author}) client.post("/books", data={"title": removed_title, "author": removed_author}) client.post("/books", data={"title": last_title, "author": last_author}) client.post("/books/2/remove") response = client.get("/") assert response.status_code == 200 first_position = response.data.index(first_title.encode()) last_position = response.data.index(last_title.encode()) assert first_position < last_position assert removed_title.encode() not in response.data === END AC removal-preserves-remaining-order ===

User Acceptance

• A reader can remove a listed book and see the updated list.

Guardrails

• Removal must go through the persistence boundary.
• Removing one book must never reorder the remaining books.