chore: bring the test suite up to ruff's standards

Mostly automatic: empty f-strings, unused imports, formatting. The manual half
was duplicated import blocks stranded mid-file and `== None` assertions, which
become `is None` here because they compare plain attributes -- unlike the
identical rule in filters/book.py, where they build SQL.

Two unused variables are the tests never checking the disk in either
delete_files direction. Left in place under a noqa so the gap stays visible.

TODO.md

@@ -114,6 +114,24 @@ CMD ["litestar", "--app-dir", "chitai", "run", "--host", "0.0.0.0", "--port", "8
 `litestar run` is the CLI development runner. Production should invoke uvicorn or granian
 directly, with a worker count.
 
+### The delete_files flag is untested in both directions
+
+`backend/tests/integration/test_book.py` — `test_remove_file_with_delete_files_false_keeps_filesystem_file`
+and `test_remove_file_with_delete_files_true_removes_filesystem_file`
+
+Both tests capture the file's path and then assert only `response.status_code == 204`.
+Neither looks at the disk. So the flag that decides whether removing a file from a book
+also **erases it from the filesystem** is covered in name only, in both directions.
+
+Ruff surfaced this as two `F841` unused variables; the variables carry a `# noqa: F841`
+and a comment rather than being deleted, so the gap stays visible. Remove the noqa when
+the assertions land.
+
+The reason it is not a two-line fix: `FileMetadata.path` is stored relative to `book.path`,
+so the test has to resolve it against the library root to know what to stat. That
+resolution is the same thing `BookService.get_files` is recorded as getting wrong (see
+`backend/AGENTS.md`), so it is worth settling once and using in both places.
+
 ### No type checker on the backend
 
 Formatting, linting and tests now run in CI (`.gitea/workflows/ci.yml`) and block, and the

backend/tests/conftest.py

@@ -2,6 +2,8 @@ from pathlib import Path
 from uuid import uuid4
 import pytest
 
+from chitai import services
+
 from advanced_alchemy.base import UUIDAuditBase
 from litestar.testing import AsyncTestClient
 from sqlalchemy import text
@@ -155,7 +157,6 @@ async def other_authenticated_client(
 
 
 # Service fixtures
-from chitai import services
 
 
 @pytest.fixture

backend/tests/integration/test_book.py

@@ -1,6 +1,7 @@
 import pytest
 from httpx import AsyncClient
 from pathlib import Path
+from litestar.status_codes import HTTP_400_BAD_REQUEST
 
 
 @pytest.mark.parametrize(
@@ -218,7 +219,9 @@ async def test_list_books_by_id(populated_authenticated_client: AsyncClient) ->
     compare a bigint primary key against them. Nothing called it until a screen needed
     to fetch a handful of books by id.
     """
-    response = await populated_authenticated_client.get("/books?ids=1&ids=2&pageSize=10")
+    response = await populated_authenticated_client.get(
+        "/books?ids=1&ids=2&pageSize=10"
+    )
 
     assert response.status_code == 200
     assert sorted(book["id"] for book in response.json()["items"]) == [1, 2]
@@ -228,7 +231,7 @@ async def test_get_book_by_id(populated_authenticated_client: AsyncClient) -> No
     """Test retrieving a specific book by ID."""
 
     # Retrieve the book
-    response = await populated_authenticated_client.get(f"/books/1")
+    response = await populated_authenticated_client.get("/books/1")
 
     assert response.status_code == 200
     book_data = response.json()
@@ -300,13 +303,13 @@ async def test_delete_book_metadata_only(
 
     # Delete book without deleting files
     response = await populated_authenticated_client.delete(
-        f"/books?book_ids=3&delete_files=false&library_id=1"
+        "/books?book_ids=3&delete_files=false&library_id=1"
     )
 
     assert response.status_code == 204
 
     # Verify book is deleted
-    get_response = await populated_authenticated_client.get(f"/books/3")
+    get_response = await populated_authenticated_client.get("/books/3")
     assert get_response.status_code == 404
 
 
@@ -317,7 +320,7 @@ async def test_delete_book_with_files(
 
     # Delete book and files
     response = await populated_authenticated_client.delete(
-        f"/books?book_ids=3&delete_files=true&library_id=1"
+        "/books?book_ids=3&delete_files=true&library_id=1"
     )
 
     assert response.status_code == 204
@@ -330,7 +333,7 @@ async def test_delete_specific_book_files(
 
     # Delete specific file
     response = await populated_authenticated_client.delete(
-        f"/books/1/files?file_ids=1",
+        "/books/1/files?file_ids=1",
     )
 
     assert response.status_code == 204
@@ -347,7 +350,7 @@ async def test_update_reading_progress(
     }
 
     response = await populated_authenticated_client.post(
-        f"/books/progress/1",
+        "/books/progress/1",
         json=progress_data,
     )
 
@@ -423,7 +426,9 @@ async def test_create_books_groups_formats_within_one_folder(
 ) -> None:
     """Picking a book's own folder yields one book with both formats, not two books."""
     epub = Path("tests/data_files/Metamorphosis - Franz Kafka.epub").read_bytes()
-    pdf = Path("tests/data_files/Calculus Made Easy - Silvanus Thompson.pdf").read_bytes()
+    pdf = Path(
+        "tests/data_files/Calculus Made Easy - Silvanus Thompson.pdf"
+    ).read_bytes()
 
     files = [
         ("files", ("Metamorphosis/Metamorphosis.epub", epub, "application/epub+zip")),
@@ -534,7 +539,9 @@ class TestDuplicateHandling:
                     "files",
                     (
                         "war.epub",
-                        Path("tests/data_files/The Art of War - Sun Tzu.epub").read_bytes(),
+                        Path(
+                            "tests/data_files/The Art of War - Sun Tzu.epub"
+                        ).read_bytes(),
                         "application/epub+zip",
                     ),
                 )
@@ -550,7 +557,9 @@ class TestDuplicateHandling:
                     "files",
                     (
                         "war.epub",
-                        Path("tests/data_files/The Art of War - Sun Tzu.epub").read_bytes(),
+                        Path(
+                            "tests/data_files/The Art of War - Sun Tzu.epub"
+                        ).read_bytes(),
                         "application/epub+zip",
                     ),
                 )
@@ -736,7 +745,9 @@ class TestDuplicateBooks:
         assert len(merged["files"]) == 2
 
         # The folded record is gone, and the group it formed with it.
-        assert (await authenticated_client.get(f"/books/{fold['id']}")).status_code == 404
+        assert (
+            await authenticated_client.get(f"/books/{fold['id']}")
+        ).status_code == 404
         groups = await authenticated_client.get("/books/duplicate-books?library_id=1")
         assert groups.json() == []
 
@@ -786,16 +797,6 @@ class TestDuplicateBooks:
 # async def test_edit_book_metadata(authenticated_client: AsyncClient) -> None:
 #     raise NotImplementedError()
 
-import pytest
-import aiofiles
-from httpx import AsyncClient
-from pathlib import Path
-from litestar.status_codes import HTTP_400_BAD_REQUEST
-
-import pytest
-from httpx import AsyncClient
-from datetime import date
-
 
 class TestMetadataUpdates:
     @pytest.mark.parametrize(
@@ -849,8 +850,10 @@ class TestMetadataUpdates:
             (
                 "authors",  # Update with new authors
                 ["New Author 1", "New Author 2"],
-                lambda data: {a["name"] for a in data["authors"]}
+                lambda data: (
-                == {"New Author 1", "New Author 2"},
+                    {a["name"] for a in data["authors"]}
+                    == {"New Author 1", "New Author 2"}
+                ),
             ),
             (
                 "authors",  # Clear authors
@@ -860,8 +863,9 @@ class TestMetadataUpdates:
             (
                 "tags",  # Update with new tags
                 ["Tag 1", "Tag 2", "Tag 3"],
-                lambda data: {t["name"] for t in data["tags"]}
+                lambda data: (
-                == {"Tag 1", "Tag 2", "Tag 3"},
+                    {t["name"] for t in data["tags"]} == {"Tag 1", "Tag 2", "Tag 3"}
+                ),
             ),
             (
                 "tags",  # Clear tags
@@ -881,8 +885,10 @@ class TestMetadataUpdates:
             (
                 "identifiers",  # Update with new identifiers
                 {"isbn-13": "978-1234567890", "doi": "10.example/id"},
-                lambda data: data["identifiers"]
+                lambda data: (
-                == {"isbn-13": "978-1234567890", "doi": "10.example/id"},
+                    data["identifiers"]
+                    == {"isbn-13": "978-1234567890", "doi": "10.example/id"}
+                ),
             ),
             (
                 "identifiers",  # Clear identifiers
@@ -1053,7 +1059,7 @@ class TestMetadataUpdates:
 
         result = response.json()
 
-        assert result[updated_field] == None
+        assert result[updated_field] is None
 
     @pytest.mark.parametrize(
         ("updated_field"),
@@ -1215,7 +1221,9 @@ class TestFileManagement:
             pytest.skip("Book has no files")
 
         file_id = book_data["files"][0]["id"]
-        filename = book_data["files"][0].get("path")
+        # TODO: this test asserts only the 204 and never checks the disk, so the flag it is
+        # named for is untested. See TODO.md; drop the noqa when the assertion lands.
+        filename = book_data["files"][0].get("path")  # noqa: F841
 
         # Remove file without deleting from filesystem
         response = await populated_authenticated_client.delete(
@@ -1240,7 +1248,8 @@ class TestFileManagement:
 
         book_data = add_response.json()
         file_id = book_data["files"][-1]["id"]
-        file_path = book_data["files"][-1].get("path")
+        # TODO: as above -- the file is never checked for removal from disk.
+        file_path = book_data["files"][-1].get("path")  # noqa: F841
 
         # Remove file with deletion from filesystem
         response = await populated_authenticated_client.delete(
@@ -1295,7 +1304,9 @@ class TestUnnameableFormats:
         self, authenticated_client: AsyncClient
     ) -> None:
         response = await authenticated_client.post(
-            "/books?library_id=1", files=self.upload("Dune.mobi"), data={"library_id": 1}
+            "/books?library_id=1",
+            files=self.upload("Dune.mobi"),
+            data={"library_id": 1},
         )
 
         assert response.status_code == 201
@@ -1323,9 +1334,7 @@ class TestUnnameableFormats:
         assert detail.status_code == 200
         assert detail.json()["files"][0]["content_type"] is None
 
-    async def test_the_file_downloads(
+    async def test_the_file_downloads(self, authenticated_client: AsyncClient) -> None:
-        self, authenticated_client: AsyncClient
-    ) -> None:
         """Litestar supplies its own media type when the row carries none."""
         created = await authenticated_client.post(
             "/books?library_id=1",

backend/tests/integration/test_bookshelf.py

@@ -1,4 +1,3 @@
-import pytest
 from httpx import AsyncClient
 
 
@@ -200,7 +199,6 @@ async def test_remove_books_from_shelf(
         "/books", params={"shelves": shelf_id}
     )
 
-    
     assert books_response.status_code == 200
     assert books_response.json()["total"] == 2
 

backend/tests/integration/test_calibre_import.py

@@ -42,7 +42,9 @@ def fx_source(tmp_path: Path) -> Path:
         cover=True,
         formats={"EPUB": EPUB},
     )
-    fixture.add_book(2, "The Art of War", authors=["Sun Tzu"], formats={"EPUB": OTHER_EPUB})
+    fixture.add_book(
+        2, "The Art of War", authors=["Sun Tzu"], formats={"EPUB": OTHER_EPUB}
+    )
     fixture.add_book(3, "Metadata Only", authors=["Nobody"])
 
     return fixture.commit()
@@ -95,7 +97,8 @@ async def test_an_uploaded_library_imports(
     authenticated_client: AsyncClient, source: Path, tmp_path: Path
 ) -> None:
     status, job = await upload(
-        authenticated_client, zip_of(source, tmp_path / "out", prefix="Calibre Library/")
+        authenticated_client,
+        zip_of(source, tmp_path / "out", prefix="Calibre Library/"),
     )
 
     assert status == 202
@@ -278,7 +281,9 @@ async def test_a_second_copy_is_counted_as_a_possible_duplicate(
     padded.write_bytes(EPUB.read_bytes() + b"\0" * 64)
 
     fixture = CalibreFixture(tmp_path / "calibre")
-    fixture.add_book(1, "The Metamorphosis", authors=["Franz Kafka"], formats={"EPUB": EPUB})
+    fixture.add_book(
+        1, "The Metamorphosis", authors=["Franz Kafka"], formats={"EPUB": EPUB}
+    )
     fixture.add_book(
         2, "The Metamorphosis", authors=["Franz Kafka"], formats={"EPUB": padded}
     )

backend/tests/integration/test_file_hash.py

@@ -8,7 +8,9 @@ from pathlib import Path
 # Known KOReader hashes for test files
 TEST_FILES = {
     "Moby Dick; Or, The Whale - Herman Melville.epub": {
-        "path": Path("tests/data_files/Moby Dick; Or, The Whale - Herman Melville.epub"),
+        "path": Path(
+            "tests/data_files/Moby Dick; Or, The Whale - Herman Melville.epub"
+        ),
         "hash": "ceeef909ec65653ba77e1380dff998fb",
         "content_type": "application/epub+zip",
     },
@@ -59,7 +61,9 @@ async def test_add_file_to_book_generates_correct_hash(
     first_book = TEST_FILES["Moby Dick; Or, The Whale - Herman Melville.epub"]
     first_content = first_book["path"].read_bytes()
 
-    files = [("files", (first_book["path"].name, first_content, first_book["content_type"]))]
+    files = [
+        ("files", (first_book["path"].name, first_content, first_book["content_type"]))
+    ]
     data = {"library_id": "1"}
 
     create_response = await authenticated_client.post(
@@ -75,7 +79,12 @@ async def test_add_file_to_book_generates_correct_hash(
     second_book = TEST_FILES["Calculus Made Easy - Silvanus Thompson.pdf"]
     second_content = second_book["path"].read_bytes()
 
-    add_files = [("data", (second_book["path"].name, second_content, second_book["content_type"]))]
+    add_files = [
+        (
+            "data",
+            (second_book["path"].name, second_content, second_book["content_type"]),
+        )
+    ]
 
     add_response = await authenticated_client.post(
         f"/books/{book_id}/files",

backend/tests/integration/test_library.py

@@ -40,5 +40,5 @@ async def test_create_library(
         assert result["name"] == "Test Library"
         assert result["root_path"] == f"{tmp_path}/books"
         assert result["path_template"] == "{author}/{title}"
-        assert result["read_only"] == False
+        assert result["read_only"] is False
         assert result["description"] is None

backend/tests/unit/test_filesystem_library.py

@@ -2,7 +2,10 @@
 
 from pathlib import Path
 
-from chitai.services.filesystem_library import BookPathGenerator, sanitize_path_component
+from chitai.services.filesystem_library import (
+    BookPathGenerator,
+    sanitize_path_component,
+)
 
 
 ROOT = Path("/library")
@@ -23,12 +26,15 @@ def test_a_book_with_no_authors() -> None:
 
 
 def test_a_series_adds_a_level_and_pads_the_position() -> None:
-    assert path_for(
+    assert (
+        path_for(
             title="Persepolis Rising",
             authors=["James S. A. Corey"],
             series="The Expanse",
             series_position="7",
-    ) == ROOT / "James S. A. Corey" / "The Expanse" / "07 - Persepolis Rising"
+        )
+        == ROOT / "James S. A. Corey" / "The Expanse" / "07 - Persepolis Rising"
+    )
 
 
 def test_a_slash_in_a_title_does_not_add_a_directory() -> None:
@@ -43,16 +49,25 @@ def test_a_slash_in_a_title_does_not_add_a_directory() -> None:
     generated = path_for(title="Back in Black: AC/DC", authors=["Murray Engleheart"])
 
     assert generated == ROOT / "Murray Engleheart" / "Back in Black: AC_DC"
-    assert generated.relative_to(ROOT).parts == ("Murray Engleheart", "Back in Black: AC_DC")
+    assert generated.relative_to(ROOT).parts == (
+        "Murray Engleheart",
+        "Back in Black: AC_DC",
+    )
 
 
 def test_a_slash_in_an_author_or_series_is_handled_too() -> None:
     assert path_for(title="Split", authors=["A/B Collective"]) == (
         ROOT / "A_B Collective" / "Split"
     )
-    assert path_for(
+    assert (
-        title="Volume One", authors=["Someone"], series="Either/Or", series_position="1"
+        path_for(
-    ) == ROOT / "Someone" / "Either_Or" / "01 - Volume One"
+            title="Volume One",
+            authors=["Someone"],
+            series="Either/Or",
+            series_position="1",
+        )
+        == ROOT / "Someone" / "Either_Or" / "01 - Volume One"
+    )
 
 
 def test_control_characters_are_removed() -> None:

backend/tests/unit/test_matching.py

@@ -54,7 +54,8 @@ class TestNormalizeTitle:
         assert normalize_title("The") == "the"
 
     @pytest.mark.parametrize(
-        "title", ["Catch 22", "Fahrenheit 451", "Blade Runner 2049", "1984", "Apollo 13"]
+        "title",
+        ["Catch 22", "Fahrenheit 451", "Blade Runner 2049", "1984", "Apollo 13"],
     )
     def test_a_number_is_not_an_edition(self, title: str) -> None:
         """Edition stripping keys on the `e`; a bare number is part of the title."""
@@ -163,8 +164,13 @@ class TestNormalizeIdentifier:
 
     def test_uuids_are_refused(self) -> None:
         """Generated per build, so they only re-find what the hash check catches."""
-        assert normalize_identifier("uuid", "3f2b1c4e-1111-2222-3333-444455556666") is None
+        assert (
-        assert normalize_identifier("urn:uuid", "3f2b1c4e-1111-2222-3333-444455556666") is None
+            normalize_identifier("uuid", "3f2b1c4e-1111-2222-3333-444455556666") is None
+        )
+        assert (
+            normalize_identifier("urn:uuid", "3f2b1c4e-1111-2222-3333-444455556666")
+            is None
+        )
 
     def test_other_schemes_keep_their_own_key(self) -> None:
         assert normalize_identifier("asin", "B000FC0PDA") == "asin:b000fc0pda"
@@ -187,7 +193,9 @@ class TestIsbnConversion:
         assert isbn10_to_isbn13("043942089X") == "9780439420891"
 
     @pytest.mark.parametrize("isbn", ["0486282113", "9780486282114", "nonsense"])
-    def test_anything_that_is_not_an_isbn_10_converts_to_nothing(self, isbn: str) -> None:
+    def test_anything_that_is_not_an_isbn_10_converts_to_nothing(
+        self, isbn: str
+    ) -> None:
         assert isbn10_to_isbn13(isbn) is None
 
 
@@ -219,7 +227,7 @@ class TestParseIdentifier:
         assert parse_identifier("B000FC0PDA", "mobi-asin") == ("asin", "B000FC0PDA")
 
     def test_an_unrecognised_prefix_is_part_of_the_value(self) -> None:
-        """"http://example.com/book" is not an identifier called "http"."""
+        """ "http://example.com/book" is not an identifier called "http"."""
         assert parse_identifier("http://www.gutenberg.org/5200") == (
             "id",
             "http://www.gutenberg.org/5200",

backend/tests/unit/test_metadata_extractor.py

@@ -22,7 +22,6 @@ class TestEpubExtractor:
         assert metadata["published_date"] == date(year=2001, month=7, day=1)
 
 
-
 EPUB = Path("tests/data_files/Metamorphosis - Franz Kafka.epub")
 PDF = Path("tests/data_files/Calculus Made Easy - Silvanus Thompson.pdf")
 
@@ -31,7 +30,9 @@ PDF = Path("tests/data_files/Calculus Made Easy - Silvanus Thompson.pdf")
 class TestIdentifierMerging:
     """A book's formats each contribute identifiers; none of them replaces the rest."""
 
-    async def test_every_format_contributes(self, monkeypatch: pytest.MonkeyPatch) -> None:
+    async def test_every_format_contributes(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
         """
         Identifiers are a collection, not a single value.
 
@@ -47,7 +48,9 @@ class TestIdentifierMerging:
             }
 
         async def pdf(_file):
-            return {"identifiers": {"isbn-13": "9781718500402", "isbn-10": "1593270356"}}
+            return {
+                "identifiers": {"isbn-13": "9781718500402", "isbn-10": "1593270356"}
+            }
 
         monkeypatch.setattr(EpubExtractor, "extract_metadata", epub)
         monkeypatch.setattr(PdfExtractor, "extract_metadata", pdf)
@@ -133,7 +136,9 @@ class TestSplitEdition:
             ),
         ],
     )
-    def test_editions_are_split_out(self, title: str, stripped: str, edition: int) -> None:
+    def test_editions_are_split_out(
+        self, title: str, stripped: str, edition: int
+    ) -> None:
         assert split_edition(title) == (stripped, edition)
 
     @pytest.mark.parametrize(
@@ -171,7 +176,10 @@ class TestEditionFromFiles:
         """The PDF fixture calls itself a 2nd edition in its own metadata title."""
         metadata = await Extractor.extract_metadata([PDF])
 
-        assert metadata["title"] == "The Project Gutenberg eBook #33283: Calculus Made Easy"
+        assert (
+            metadata["title"]
+            == "The Project Gutenberg eBook #33283: Calculus Made Easy"
+        )
         assert metadata["edition"] == 2
 
 

backend/tests/unit/test_services/test_book_service.py

@@ -25,7 +25,9 @@ PDF = DATA_FILES / "Calculus Made Easy - Silvanus Thompson.pdf"
 def upload(path: Path, name: str | None = None) -> UploadFile:
     """An uploaded file carrying the bytes of one of the test fixtures."""
     return UploadFile(
-        content_type="application/pdf" if path.suffix == ".pdf" else "application/epub+zip",
+        content_type="application/pdf"
+        if path.suffix == ".pdf"
+        else "application/epub+zip",
         filename=name or path.name,
         file_data=path.read_bytes(),
     )
@@ -538,9 +540,7 @@ class TestBookPathCollisions:
 
         assert original.path != forced.path
 
-        paths = {
+        paths = {Path(book.path) / book.files[0].path for book in (original, forced)}
-            Path(book.path) / book.files[0].path for book in (original, forced)
-        }
         assert len(paths) == 2
         assert all(path.is_file() for path in paths)
 
@@ -581,7 +581,10 @@ class TestBookPathCollisions:
         # Renamed onto the first book's author and title.
         await books_service.update_book(
             second.books[0].id,
-            {"title": original.title, "authors": [author.name for author in original.authors]},
+            {
+                "title": original.title,
+                "authors": [author.name for author in original.authors],
+            },
             test_library,
         )
 
@@ -743,7 +746,8 @@ class TestDuplicateBooks:
         )
 
         matches = await books_service.find_duplicate_books(
-            {"title": "Building Microservices", "authors": ["Newman, Sam;"]}, test_library
+            {"title": "Building Microservices", "authors": ["Newman, Sam;"]},
+            test_library,
         )
 
         assert [match.book_id for match in matches] == [stored.id]
@@ -834,16 +838,22 @@ class TestDuplicateBooks:
             "series": "Foundation",
         }
 
-        assert await books_service.find_duplicate_books(
+        assert (
+            await books_service.find_duplicate_books(
                 incoming | {"series_position": "2"}, test_library
-        ) == []
+            )
+            == []
+        )
 
         # The same volume, written a little differently, still matches.
-        assert len(
+        assert (
+            len(
                 await books_service.find_duplicate_books(
                     incoming | {"series_position": "1.0"}, test_library
                 )
-        ) == 1
+            )
+            == 1
+        )
 
     async def test_a_book_is_not_its_own_duplicate(
         self, books_service: BookService, test_library: m.Library
@@ -909,7 +919,10 @@ class TestAuthorNames:
         existing row and then collides with it on the unique index.
         """
         first = await store_book(
-            books_service, test_library, title="Building Microservices", authors=["Sam Newman"]
+            books_service,
+            test_library,
+            title="Building Microservices",
+            authors=["Sam Newman"],
         )
         second = await store_book(
             books_service,
@@ -953,7 +966,9 @@ class TestAuthorNames:
         "Franz Kafka.epub" is not a person.
         """
         result = await books_service.create_many_from_files(
-            BooksCreateFromFiles(files=[upload(EPUB, "Some Unknown Book - Ada Lovelace.epub")]),
+            BooksCreateFromFiles(
+                files=[upload(EPUB, "Some Unknown Book - Ada Lovelace.epub")]
+            ),
             test_library,
         )
 
@@ -1014,7 +1029,10 @@ class TestMergeBooks:
     ) -> None:
         """The survivor keeps its own fields unless the caller says otherwise."""
         keep = await store_book(
-            books_service, test_library, title="Building Microservices", authors=["Sam Newman"]
+            books_service,
+            test_library,
+            title="Building Microservices",
+            authors=["Sam Newman"],
         )
         fold = await store_book(
             books_service,
@@ -1030,7 +1048,11 @@ class TestMergeBooks:
         assert merged.publisher is None
 
         other = await store_book(
-            books_service, test_library, title="Monolith", authors=["Sam Newman"], edition=3
+            books_service,
+            test_library,
+            title="Monolith",
+            authors=["Sam Newman"],
+            edition=3,
         )
         merged = await books_service.merge_books(
             keep.id, [other.id], test_library, metadata={"edition": 3}
@@ -1096,10 +1118,14 @@ class TestMergeBooks:
         await books_service.merge_books(keep.id, [fold.id], test_library)
 
         rows = (
+            (
                 await books_service.repository.session.execute(
                     select(m.BookProgress).where(m.BookProgress.book_id == keep.id)
                 )
-        ).scalars().all()
+            )
+            .scalars()
+            .all()
+        )
 
         assert [row.percentage for row in rows] == [0.6]
 
@@ -1112,13 +1138,23 @@ class TestMergeBooks:
     ) -> None:
         """Both books on one shelf must not leave the survivor linked to it twice."""
         keep = await store_book(
-            books_service, test_library, title="A", authors=["X"], tags=["Shared", "Only Keep"]
+            books_service,
+            test_library,
+            title="A",
+            authors=["X"],
+            tags=["Shared", "Only Keep"],
         )
         fold = await store_book(
-            books_service, test_library, title="B", authors=["X"], tags=["Shared", "Only Fold"]
+            books_service,
+            test_library,
+            title="B",
+            authors=["X"],
+            tags=["Shared", "Only Fold"],
         )
 
-        shelf = m.BookList(title="Later", user_id=test_user.id, library_id=test_library.id)
+        shelf = m.BookList(
+            title="Later", user_id=test_user.id, library_id=test_library.id
+        )
         session.add(shelf)
         await session.commit()
         session.add_all(
@@ -1131,13 +1167,21 @@ class TestMergeBooks:
 
         merged = await books_service.merge_books(keep.id, [fold.id], test_library)
 
-        assert sorted(tag.name for tag in merged.tags) == ["Only Fold", "Only Keep", "Shared"]
+        assert sorted(tag.name for tag in merged.tags) == [
+            "Only Fold",
+            "Only Keep",
+            "Shared",
+        ]
 
         links = (
+            (
                 await books_service.repository.session.execute(
                     select(m.BookListLink).where(m.BookListLink.book_id == keep.id)
                 )
-        ).scalars().all()
+            )
+            .scalars()
+            .all()
+        )
         assert len(links) == 1
 
     async def test_an_identifier_moves_only_under_a_name_the_survivor_lacks(

backend/tests/unit/test_services/test_bookshelf_service.py

@@ -2,19 +2,12 @@
 
 import pytest
 
+from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from chitai.services import ShelfService
 from chitai.database import models as m
-
-
-import pytest
-from sqlalchemy import select
-
-from chitai.services.bookshelf import ShelfService
-from chitai.services import BookService
 from chitai.database.models.book_list import BookList, BookListLink
-from chitai.database import models as m
 
 
 @pytest.fixture

backend/tests/unit/test_services/test_calibre_import_service.py

@@ -201,7 +201,9 @@ async def test_importing_twice_creates_nothing(
     ]
 
     held_by = [
-        skipped.book_id for skipped in result.skipped if skipped.reason == "already stored"
+        skipped.book_id
+        for skipped in result.skipped
+        if skipped.reason == "already stored"
     ]
     assert all(book_id is not None for book_id in held_by)
 
@@ -223,7 +225,9 @@ async def test_a_file_the_catalogue_lists_but_disk_does_not(
         await source.close()
 
     assert len(result.created) == 1
-    assert [(s.calibre_id, s.reason) for s in result.skipped] == [(2, "no files on disk")]
+    assert [(s.calibre_id, s.reason) for s in result.skipped] == [
+        (2, "no files on disk")
+    ]
 
 
 async def test_one_broken_book_does_not_stop_the_import(
@@ -312,7 +316,11 @@ async def test_shared_authors_and_tags_are_one_row_each(
         1, "One", authors=["Franz Kafka"], tags=["Fiction"], formats={"EPUB": EPUB}
     )
     fixture.add_book(
-        2, "Two", authors=["Franz Kafka"], tags=["Fiction"], formats={"EPUB": OTHER_EPUB}
+        2,
+        "Two",
+        authors=["Franz Kafka"],
+        tags=["Fiction"],
+        formats={"EPUB": OTHER_EPUB},
     )
     root = fixture.commit()
 

backend/tests/unit/test_services/test_library_service.py

@@ -34,8 +34,8 @@ class TestLibraryServiceCRUD:
         assert library.name == "Test Library"
         assert library.root_path == library_path
         assert library.path_template == "{author}/{title}"
-        assert library.description == None
+        assert library.description is None
-        assert library.read_only == False
+        assert library.read_only is False
 
         # Check if directory was created
         assert Path(library.root_path).is_dir()
@@ -56,8 +56,8 @@ class TestLibraryServiceCRUD:
             read_only=False,
         )
 
-        with pytest.raises(PermissionError) as exc_info:
+        with pytest.raises(PermissionError):
-            library = await library_service.create(library_data)
+            await library_service.create(library_data)
 
         # Check if directory was created
         assert not Path(library_path).exists()
@@ -86,8 +86,8 @@ class TestLibraryServiceCRUD:
         assert library.name == "Test Library"
         assert library.root_path == library_path
         assert library.path_template == "{author}/{title}"
-        assert library.description == None
+        assert library.description is None
-        assert library.read_only == True
+        assert library.read_only is True
 
     async def test_create_library_read_only_nonexistent_path(
         self, library_service: LibraryService, tmp_path: Path
@@ -138,7 +138,7 @@ class TestLibraryServiceCRUD:
         assert library.root_path == "./books"
         assert library.path_template == "{author}/{title}"
         assert library.description is None
-        assert library.read_only == False
+        assert library.read_only is False
 
     # async def test_delete_library_keep_files(
     #     self, session: AsyncSession, library_service: LibraryService

backend/tests/unit/test_services/test_user_service.py

@@ -21,7 +21,7 @@ class TestUserServiceAuthentication:
 
         # Create a user with a known password
         password = "password123"
-        user = m.User(email=f"test@example.com", password=password)
+        user = m.User(email="test@example.com", password=password)
 
         session.add(user)
         await session.commit()
@@ -52,7 +52,7 @@ class TestUserServiceAuthentication:
 
         # Create user
         password = "password123"
-        user = m.User(email=f"test@example.com", password=password)
+        user = m.User(email="test@example.com", password=password)
 
         session.add(user)
         await session.commit()
@@ -85,7 +85,7 @@ class TestUserServiceCRUD:
     ) -> None:
         """Test getting user by email."""
 
-        user = m.User(email=f"test@example.com", password="password123")
+        user = m.User(email="test@example.com", password="password123")
 
         session.add(user)
         await session.commit()
@@ -102,12 +102,12 @@ class TestUserServiceCRUD:
         """Test creating a new user with a duplicate email."""
 
         # Create first user
-        user = m.User(email=f"test@example.com", password="password123")
+        user = m.User(email="test@example.com", password="password123")
         session.add(user)
         await session.commit()
 
         # Create second user
-        user = m.User(email=f"test@example.com", password="password12345")
+        user = m.User(email="test@example.com", password="password12345")
 
         with pytest.raises(IntegrityError) as exc_info:
             session.add(user)