Skip missing books in IA carousels

openlibrary/plugins/openlibrary/home.py

@@ -171,7 +171,8 @@ def get_ia_carousel_books(query=None, subject=None, sorts=None, limit=None, safe
         query=query,
         safe_mode=safe_mode,
     )
-    formatted_books = [format_book_data(book, False) for book in books if book != "error"]
+    formatted_books = [format_book_data(book, False) for book in books if book and book != "error"]
+
     return formatted_books
 
 

openlibrary/plugins/openlibrary/tests/test_home.py

@@ -137,6 +137,15 @@ def spoofed_generic_carousel(*args, **kwargs):
         assert "About the Project" in html
 
 
+class Test_get_ia_carousel_books:
+    def test_skips_missing_books(self, monkeypatch):
+        book = web.storage(key="/books/OL1M")
+        monkeypatch.setattr(home.lending, "get_available", lambda **kwargs: [book, None, "error"])
+        monkeypatch.setattr(home, "format_book_data", lambda book, fetch_availability: {"key": book.key})
+
+        assert home.get_ia_carousel_books() == [{"key": "/books/OL1M"}]
+
+
 class Test_format_book_data:
     def test_all(self, mock_site, mock_ia):
         mock_site.quicksave("/books/OL1M", "/type/edition", title="Foo")