Address RUF012

beets/dbcore/db.py

@@ -29,7 +29,7 @@ from collections import defaultdict
 from collections.abc import Mapping
 from functools import cached_property
 from sqlite3 import sqlite_version_info
-from typing import TYPE_CHECKING, Any, AnyStr, Generic
+from typing import TYPE_CHECKING, Any, AnyStr, ClassVar, Generic
 
 from typing_extensions import (
     Self,
@@ -299,7 +299,7 @@ class Model(ABC, Generic[D]):
     """The flex field SQLite table name.
     """
 
-    _fields: dict[str, types.Type] = {}
+    _fields: ClassVar[dict[str, types.Type]] = {}
     """A mapping indicating available "fixed" fields on this type. The
     keys are field names and the values are `Type` objects.
     """
@@ -314,7 +314,7 @@ class Model(ABC, Generic[D]):
         """Optional types for non-fixed (flexible and computed) fields."""
         return {}
 
-    _sorts: dict[str, type[FieldSort]] = {}
+    _sorts: ClassVar[dict[str, type[FieldSort]]] = {}
     """Optional named sort criteria. The keys are strings and the values
     are subclasses of `Sort`.
     """

beets/dbcore/query.py

@@ -25,7 +25,7 @@ from datetime import datetime, timedelta
 from functools import cached_property, reduce
 from operator import mul, or_
 from re import Pattern
-from typing import TYPE_CHECKING, Any, Generic, TypeVar
+from typing import TYPE_CHECKING, Any, ClassVar, Generic, TypeVar
 
 from beets import util
 from beets.util.units import raw_seconds_short
@@ -691,7 +691,12 @@ class Period:
         ("%Y-%m-%dT%H:%M", "%Y-%m-%d %H:%M"),  # minute
         ("%Y-%m-%dT%H:%M:%S", "%Y-%m-%d %H:%M:%S"),  # second
     )
-    relative_units = {"y": 365, "m": 30, "w": 7, "d": 1}
+    relative_units: ClassVar[dict[str, int]] = {
+        "y": 365,
+        "m": 30,
+        "w": 7,
+        "d": 1,
+    }
     relative_re = "(?P<sign>[+|-]?)(?P<quantity>[0-9]+)(?P<timespan>[y|m|w|d])"
 
     def __init__(self, date: datetime, precision: str):

beets/dbcore/types.py

@@ -20,7 +20,7 @@ import re
 import time
 import typing
 from abc import ABC
-from typing import TYPE_CHECKING, Any, Generic, TypeVar, cast
+from typing import TYPE_CHECKING, Any, ClassVar, Generic, TypeVar, cast
 
 import beets
 from beets import util
@@ -406,7 +406,7 @@ class MusicalKey(String):
     The standard format is C, Cm, C#, C#m, etc.
     """
 
-    ENHARMONIC = {
+    ENHARMONIC: ClassVar[dict[str, str]] = {
         r"db": "c#",
         r"eb": "d#",
         r"gb": "f#",

beets/library/models.py

@@ -7,7 +7,7 @@ import time
 import unicodedata
 from functools import cached_property
 from pathlib import Path
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, ClassVar
 
 from mediafile import MediaFile, UnreadableFileError
 
@@ -229,7 +229,7 @@ class Album(LibModel):
     _table = "albums"
     _flex_table = "album_attributes"
     _always_dirty = True
-    _fields = {
+    _fields: ClassVar[dict[str, types.Type]] = {
         "id": types.PRIMARY_ID,
         "artpath": types.NullPathType(),
         "added": types.DATE,
@@ -281,13 +281,13 @@ class Album(LibModel):
     def _types(cls) -> dict[str, types.Type]:
         return {**super()._types, "path": types.PathType()}
 
-    _sorts = {
+    _sorts: ClassVar[dict[str, type[dbcore.query.FieldSort]]] = {
         "albumartist": dbcore.query.SmartArtistSort,
         "artist": dbcore.query.SmartArtistSort,
     }
 
     # List of keys that are set on an album's items.
-    item_keys = [
+    item_keys: ClassVar[list[str]] = [
         "added",
         "albumartist",
         "albumartists",
@@ -624,7 +624,7 @@ class Item(LibModel):
 
     _table = "items"
     _flex_table = "item_attributes"
-    _fields = {
+    _fields: ClassVar[dict[str, types.Type]] = {
         "id": types.PRIMARY_ID,
         "path": types.PathType(),
         "album_id": types.FOREIGN_ID,
@@ -744,7 +744,9 @@ class Item(LibModel):
 
     _formatter = FormattedItemMapping
 
-    _sorts = {"artist": dbcore.query.SmartArtistSort}
+    _sorts: ClassVar[dict[str, type[dbcore.query.FieldSort]]] = {
+        "artist": dbcore.query.SmartArtistSort
+    }
 
     @cached_classproperty
     def _queries(cls) -> dict[str, FieldQueryType]:

beets/plugins.py

@@ -141,7 +141,13 @@ class PluginLogFilter(logging.Filter):
 # Managing the plugins themselves.
 
 
-class BeetsPlugin(metaclass=abc.ABCMeta):
+class BeetsPluginMeta(abc.ABCMeta):
+    template_funcs: ClassVar[TFuncMap[str]] = {}
+    template_fields: ClassVar[TFuncMap[Item]] = {}
+    album_template_fields: ClassVar[TFuncMap[Album]] = {}
+
+
+class BeetsPlugin(metaclass=BeetsPluginMeta):
     """The base class for all beets plugins. Plugins provide
     functionality by defining a subclass of BeetsPlugin and overriding
     the abstract methods defined here.
@@ -151,9 +157,10 @@ class BeetsPlugin(metaclass=abc.ABCMeta):
         list
     )
     listeners: ClassVar[dict[EventType, list[Listener]]] = defaultdict(list)
-    template_funcs: ClassVar[TFuncMap[str]] | TFuncMap[str] = {}  # type: ignore[valid-type]
-    template_fields: ClassVar[TFuncMap[Item]] | TFuncMap[Item] = {}  # type: ignore[valid-type]
-    album_template_fields: ClassVar[TFuncMap[Album]] | TFuncMap[Album] = {}  # type: ignore[valid-type]
+
+    template_funcs: TFuncMap[str]
+    template_fields: TFuncMap[Item]
+    album_template_fields: TFuncMap[Album]
 
     name: str
     config: ConfigView
@@ -220,14 +227,10 @@ class BeetsPlugin(metaclass=abc.ABCMeta):
         self.name = name or self.__module__.split(".")[-1]
         self.config = beets.config[self.name]
 
-        # If the class attributes are not set, initialize as instance attributes.
-        # TODO: Revise with v3.0.0, see also type: ignore[valid-type] above
-        if not self.template_funcs:
-            self.template_funcs = {}
-        if not self.template_fields:
-            self.template_fields = {}
-        if not self.album_template_fields:
-            self.album_template_fields = {}
+        # create per-instance storage for template fields and functions
+        self.template_funcs = {}
+        self.template_fields = {}
+        self.album_template_fields = {}
 
         self.early_import_stages = []
         self.import_stages = []

beets/test/helper.py

@@ -524,7 +524,7 @@ class ImportHelper(TestHelper):
     autotagging library and several assertions for the library.
     """
 
-    default_import_config = {
+    default_import_config: ClassVar[dict[str, bool]] = {
         "autotag": True,
         "copy": True,
         "hardlink": False,
@@ -880,7 +880,7 @@ class FetchImageHelper:
     def run(self, *args, **kwargs):
         super().run(*args, **kwargs)
 
-    IMAGEHEADER: dict[str, bytes] = {
+    IMAGEHEADER: ClassVar[dict[str, bytes]] = {
         "image/jpeg": b"\xff\xd8\xff\x00\x00\x00JFIF",
         "image/png": b"\211PNG\r\n\032\n",
         "image/gif": b"GIF89a",

beetsplug/acousticbrainz.py

@@ -15,6 +15,7 @@
 """Fetch various AcousticBrainz metadata using MBID."""
 
 from collections import defaultdict
+from typing import ClassVar
 
 import requests
 
@@ -55,7 +56,7 @@ ABSCHEME = {
 
 
 class AcousticPlugin(plugins.BeetsPlugin):
-    item_types = {
+    item_types: ClassVar[dict[str, types.Type]] = {
         "average_loudness": types.Float(6),
         "chords_changes_rate": types.Float(6),
         "chords_key": types.STRING,

beetsplug/bpd/__init__.py

@@ -26,7 +26,7 @@ import sys
 import time
 import traceback
 from string import Template
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, ClassVar
 
 import beets
 import beets.ui
@@ -1344,7 +1344,7 @@ class Server(BaseServer):
 
     # Searching.
 
-    tagtype_map = {
+    tagtype_map: ClassVar[dict[str, str]] = {
         "Artist": "artist",
         "ArtistSort": "artist_sort",
         "Album": "album",

beetsplug/deezer.py

@@ -18,7 +18,7 @@ from __future__ import annotations
 
 import collections
 import time
-from typing import TYPE_CHECKING, Literal
+from typing import TYPE_CHECKING, ClassVar, Literal
 
 import requests
 
@@ -37,7 +37,7 @@ if TYPE_CHECKING:
 
 
 class DeezerPlugin(SearchApiMetadataSourcePlugin[IDResponse]):
-    item_types = {
+    item_types: ClassVar[dict[str, types.Type]] = {
         "deezer_track_rank": types.INTEGER,
         "deezer_track_id": types.INTEGER,
         "deezer_updated": types.DATE,

beetsplug/fetchart.py

@@ -355,7 +355,7 @@ class ArtSource(RequestMixin, ABC):
     # Specify whether this source fetches local or remote images
     LOC: ClassVar[SourceLocation]
     # A list of methods to match metadata, sorted by descending accuracy
-    VALID_MATCHING_CRITERIA: list[str] = ["default"]
+    VALID_MATCHING_CRITERIA: ClassVar[list[str]] = ["default"]
     # A human-readable name for the art source
     NAME: ClassVar[str]
     # The key to select the art source in the config. This value will also be
@@ -518,8 +518,8 @@ class RemoteArtSource(ArtSource):
 class CoverArtArchive(RemoteArtSource):
     NAME = "Cover Art Archive"
     ID = "coverart"
-    VALID_MATCHING_CRITERIA = ["release", "releasegroup"]
-    VALID_THUMBNAIL_SIZES = [250, 500, 1200]
+    VALID_MATCHING_CRITERIA: ClassVar[list[str]] = ["release", "releasegroup"]
+    VALID_THUMBNAIL_SIZES: ClassVar[list[int]] = [250, 500, 1200]
 
     URL = "https://coverartarchive.org/release/{mbid}"
     GROUP_URL = "https://coverartarchive.org/release-group/{mbid}"
@@ -1128,7 +1128,7 @@ class LastFM(RemoteArtSource):
     ID = "lastfm"
 
     # Sizes in priority order.
-    SIZES = OrderedDict(
+    SIZES: ClassVar[dict[str, tuple[int, int]]] = OrderedDict(
         [
             ("mega", (300, 300)),
             ("extralarge", (300, 300)),

beetsplug/lyrics.py

@@ -26,7 +26,7 @@ from functools import cached_property, partial, total_ordering
 from html import unescape
 from itertools import groupby
 from pathlib import Path
-from typing import TYPE_CHECKING, NamedTuple
+from typing import TYPE_CHECKING, ClassVar, NamedTuple
 from urllib.parse import quote, quote_plus, urlencode, urlparse
 
 import langdetect
@@ -367,7 +367,7 @@ class LRCLib(Backend):
 class MusiXmatch(Backend):
     URL_TEMPLATE = "https://www.musixmatch.com/lyrics/{}/{}"
 
-    REPLACEMENTS = {
+    REPLACEMENTS: ClassVar[dict[str, str]] = {
         r"\s+": "-",
         "<": "Less_Than",
         ">": "Greater_Than",
@@ -600,7 +600,7 @@ class Google(SearchBackend):
     SEARCH_URL = "https://www.googleapis.com/customsearch/v1"
 
     #: Exclude some letras.mus.br pages which do not contain lyrics.
-    EXCLUDE_PAGES = [
+    EXCLUDE_PAGES: ClassVar[list[str]] = [
         "significado.html",
         "traduccion.html",
         "traducao.html",
@@ -630,9 +630,12 @@ class Google(SearchBackend):
     #: Split cleaned up URL title into artist and title parts.
     URL_TITLE_PARTS_RE = re.compile(r" +(?:[ :|-]+|par|by) +|, ")
 
-    SOURCE_DIST_FACTOR = {"www.azlyrics.com": 0.5, "www.songlyrics.com": 0.6}
+    SOURCE_DIST_FACTOR: ClassVar[dict[str, float]] = {
+        "www.azlyrics.com": 0.5,
+        "www.songlyrics.com": 0.6,
+    }
 
-    ignored_domains: set[str] = set()
+    ignored_domains: ClassVar[set[str]] = set()
 
     @classmethod
     def pre_process_html(cls, html: str) -> str:
@@ -937,7 +940,7 @@ class RestFiles:
 
 
 class LyricsPlugin(LyricsRequestHandler, plugins.BeetsPlugin):
-    BACKEND_BY_NAME = {
+    BACKEND_BY_NAME: ClassVar[dict[str, type[Backend]]] = {
         b.name: b for b in [LRCLib, Google, Genius, Tekstowo, MusiXmatch]
     }
 

beetsplug/metasync/__init__.py

@@ -14,14 +14,20 @@
 
 """Synchronize information from music player libraries"""
 
+from __future__ import annotations
+
 from abc import ABCMeta, abstractmethod
 from importlib import import_module
+from typing import TYPE_CHECKING, ClassVar
 
 from confuse import ConfigValueError
 
 from beets import ui
 from beets.plugins import BeetsPlugin
 
+if TYPE_CHECKING:
+    from beets.dbcore import types
+
 METASYNC_MODULE = "beetsplug.metasync"
 
 # Dictionary to map the MODULE and the CLASS NAME of meta sources
@@ -32,8 +38,9 @@ SOURCES = {
 
 
 class MetaSource(metaclass=ABCMeta):
+    item_types: ClassVar[dict[str, types.Type]]
+
     def __init__(self, config, log):
-        self.item_types = {}
         self.config = config
         self._log = log
 

beetsplug/metasync/amarok.py

@@ -17,6 +17,7 @@
 from datetime import datetime
 from os.path import basename
 from time import mktime
+from typing import ClassVar
 from xml.sax.saxutils import quoteattr
 
 from beets.dbcore import types
@@ -35,7 +36,7 @@ dbus = import_dbus()
 
 
 class Amarok(MetaSource):
-    item_types = {
+    item_types: ClassVar[dict[str, types.Type]] = {
         "amarok_rating": types.INTEGER,
         "amarok_score": types.FLOAT,
         "amarok_uid": types.STRING,

beetsplug/metasync/itunes.py

@@ -20,6 +20,7 @@ import shutil
 import tempfile
 from contextlib import contextmanager
 from time import mktime
+from typing import ClassVar
 from urllib.parse import unquote, urlparse
 
 from confuse import ConfigValueError
@@ -58,7 +59,7 @@ def _norm_itunes_path(path):
 
 
 class Itunes(MetaSource):
-    item_types = {
+    item_types: ClassVar[dict[str, types.Type]] = {
         "itunes_rating": types.INTEGER,  # 0..100 scale
         "itunes_playcount": types.INTEGER,
         "itunes_skipcount": types.INTEGER,

beetsplug/missing.py

@@ -18,7 +18,7 @@
 from __future__ import annotations
 
 from collections import defaultdict
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, ClassVar
 
 import requests
 
@@ -96,7 +96,7 @@ def _item(track_info, album_info, album_id):
 class MissingPlugin(MusicBrainzAPIMixin, BeetsPlugin):
     """List missing tracks"""
 
-    album_types = {
+    album_types: ClassVar[dict[str, types.Type]] = {
         "missing": types.INTEGER,
     }
 

beetsplug/mpdstats.py

@@ -15,6 +15,7 @@
 
 import os
 import time
+from typing import ClassVar
 
 import mpd
 
@@ -318,7 +319,7 @@ class MPDStats:
 
 
 class MPDStatsPlugin(plugins.BeetsPlugin):
-    item_types = {
+    item_types: ClassVar[dict[str, types.Type]] = {
         "play_count": types.INTEGER,
         "skip_count": types.INTEGER,
         "last_played": types.DATE,

beetsplug/playlist.py

@@ -15,7 +15,7 @@ from __future__ import annotations
 import os
 import tempfile
 from pathlib import Path
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, ClassVar
 
 import beets
 from beets.dbcore.query import BLOB_TYPE, InQuery
@@ -24,6 +24,8 @@ from beets.util import path_as_posix
 if TYPE_CHECKING:
     from collections.abc import Sequence
 
+    from beets.dbcore.query import FieldQueryType
+
 
 def is_m3u_file(path: str) -> bool:
     return Path(path).suffix.lower() in {".m3u", ".m3u8"}
@@ -85,7 +87,9 @@ class PlaylistQuery(InQuery[bytes]):
 
 
 class PlaylistPlugin(beets.plugins.BeetsPlugin):
-    item_queries = {"playlist": PlaylistQuery}
+    item_queries: ClassVar[dict[str, FieldQueryType]] = {
+        "playlist": PlaylistQuery
+    }
 
     def __init__(self):
         super().__init__()

beetsplug/spotify.py

@@ -27,7 +27,7 @@ import re
 import threading
 import time
 import webbrowser
-from typing import TYPE_CHECKING, Any, Literal
+from typing import TYPE_CHECKING, Any, ClassVar, Literal
 
 import confuse
 import requests
@@ -88,7 +88,7 @@ class AudioFeaturesUnavailableError(Exception):
 class SpotifyPlugin(
     SearchApiMetadataSourcePlugin[SearchResponseAlbums | SearchResponseTracks]
 ):
-    item_types = {
+    item_types: ClassVar[dict[str, types.Type]] = {
         "spotify_track_popularity": types.INTEGER,
         "spotify_acousticness": types.FLOAT,
         "spotify_danceability": types.FLOAT,
@@ -114,7 +114,7 @@ class SpotifyPlugin(
     track_url = "https://api.spotify.com/v1/tracks/"
     audio_features_url = "https://api.spotify.com/v1/audio-features/"
 
-    spotify_audio_features = {
+    spotify_audio_features: ClassVar[dict[str, str]] = {
         "acousticness": "spotify_acousticness",
         "danceability": "spotify_danceability",
         "energy": "spotify_energy",

beetsplug/the.py

@@ -15,6 +15,7 @@
 """Moves patterns in path formats (suitable for moving articles)."""
 
 import re
+from typing import ClassVar
 
 from beets.plugins import BeetsPlugin
 
@@ -27,7 +28,7 @@ FORMAT = "{}, {}"
 
 
 class ThePlugin(BeetsPlugin):
-    patterns: list[str] = []
+    patterns: ClassVar[list[str]] = []
 
     def __init__(self):
         super().__init__()

docs/extensions/conf.py

@@ -72,10 +72,10 @@ class ConfDomain(Domain):
 
     name = "conf"
     label = "Simple Configuration"
-    object_types = {"conf": ObjType("conf", "conf")}
-    directives = {"conf": Conf}
-    roles = {"conf": XRefRole()}
-    initial_data: dict[str, Any] = {"objects": {}}
+    object_types = {"conf": ObjType("conf", "conf")}  # noqa: RUF012
+    directives = {"conf": Conf}  # noqa: RUF012
+    roles = {"conf": XRefRole()}  # noqa: RUF012
+    initial_data: dict[str, Any] = {"objects": {}}  # noqa: RUF012
 
     def get_objects(self) -> Iterable[tuple[str, str, str, str, str, int]]:
         """Return an iterable of object tuples for the inventory."""

test/plugins/lyrics_pages.py

@@ -24,7 +24,7 @@ class LyricsPage(NamedTuple):
     artist: str = "The Beatles"
     track_title: str = "Lady Madonna"
     url_title: str | None = None  # only relevant to the Google backend
-    marks: list[str] = []  # markers for pytest.param
+    marks: list[str] = []  # markers for pytest.param  # noqa: RUF012
 
     def __str__(self) -> str:
         """Return name of this test case."""

test/plugins/test_bpd.py

@@ -22,6 +22,7 @@ import threading
 import time
 import unittest
 from contextlib import contextmanager
+from typing import ClassVar
 from unittest.mock import MagicMock, patch
 
 import confuse
@@ -837,7 +838,7 @@ class BPDQueueTest(BPDTestHelper):
         fail=True,
     )
 
-    METADATA = {"Pos", "Time", "Id", "file", "duration"}
+    METADATA: ClassVar[set[str]] = {"Pos", "Time", "Id", "file", "duration"}
 
     def test_cmd_add(self):
         with self.run_bpd() as client:
@@ -1032,7 +1033,7 @@ class BPDConnectionTest(BPDTestHelper):
         }
     )
 
-    ALL_MPD_TAGTYPES = {
+    ALL_MPD_TAGTYPES: ClassVar[set[str]] = {
         "Artist",
         "ArtistSort",
         "Album",
@@ -1057,7 +1058,7 @@ class BPDConnectionTest(BPDTestHelper):
         "MUSICBRAINZ_RELEASETRACKID",
         "MUSICBRAINZ_WORKID",
     }
-    UNSUPPORTED_TAGTYPES = {
+    UNSUPPORTED_TAGTYPES: ClassVar[set[str]] = {
         "MUSICBRAINZ_WORKID",  # not tracked by beets
         "Performer",  # not tracked by beets
         "AlbumSort",  # not tracked by beets

test/plugins/test_edit.py

@@ -13,6 +13,7 @@
 # included in all copies or substantial portions of the Software.
 
 import codecs
+from typing import ClassVar
 from unittest.mock import patch
 
 from beets.dbcore.query import TrueQuery
@@ -319,7 +320,7 @@ class EditDuringImporterTestCase(
 
     matching = AutotagStub.GOOD
 
-    IGNORED = ["added", "album_id", "id", "mtime", "path"]
+    IGNORED: ClassVar[list[str]] = ["added", "album_id", "id", "mtime", "path"]
 
     def setUp(self):
         super().setUp()

test/plugins/test_hook.py

@@ -19,7 +19,7 @@ import os
 import sys
 import unittest
 from contextlib import contextmanager
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, ClassVar
 
 from beets import plugins
 from beets.test.helper import PluginTestCase, capture_log
@@ -70,7 +70,7 @@ class HookLogsTest(HookTestCase):
 
 
 class HookCommandTest(HookTestCase):
-    EVENTS: list[plugins.EventType] = ["write", "after_write"]
+    EVENTS: ClassVar[list[plugins.EventType]] = ["write", "after_write"]
 
     def setUp(self):
         super().setUp()

test/plugins/test_mpdstats.py

@@ -13,6 +13,7 @@
 # included in all copies or substantial portions of the Software.
 
 
+from typing import Any, ClassVar
 from unittest.mock import ANY, Mock, call, patch
 
 from beets import util
@@ -46,9 +47,8 @@ class MPDStatsTest(PluginTestCase):
         assert mpdstats.get_item("/some/non-existing/path") is None
         assert "item not found:" in log.info.call_args[0][0]
 
-    FAKE_UNKNOWN_STATE = "some-unknown-one"
-    STATUSES = [
-        {"state": FAKE_UNKNOWN_STATE},
+    STATUSES: ClassVar[list[dict[str, Any]]] = [
+        {"state": "some-unknown-one"},
         {"state": "pause"},
         {"state": "play", "songid": 1, "time": "0:1"},
         {"state": "stop"},

test/plugins/test_musicbrainz.py

@@ -15,6 +15,7 @@
 """Tests for MusicBrainz API wrapper."""
 
 import unittest
+from typing import ClassVar
 from unittest import mock
 
 import pytest
@@ -1017,7 +1018,11 @@ class TestMusicBrainzPlugin(PluginMixin):
     plugin = "musicbrainz"
 
     mbid = "d2a6f856-b553-40a0-ac54-a321e8e2da99"
-    RECORDING = {"title": "foo", "id": "bar", "length": 42}
+    RECORDING: ClassVar[dict[str, int | str]] = {
+        "title": "foo",
+        "id": "bar",
+        "length": 42,
+    }
 
     @pytest.fixture
     def plugin_config(self):

test/test_dbcore.py

@@ -19,6 +19,7 @@ import shutil
 import sqlite3
 import unittest
 from tempfile import mkstemp
+from typing import ClassVar
 
 import pytest
 
@@ -57,13 +58,13 @@ class QueryFixture(dbcore.query.FieldQuery):
 class ModelFixture1(LibModel):
     _table = "test"
     _flex_table = "testflex"
-    _fields = {
+    _fields: ClassVar[dict[str, dbcore.types.Type]] = {
         "id": dbcore.types.PRIMARY_ID,
         "field_one": dbcore.types.INTEGER,
         "field_two": dbcore.types.STRING,
     }
 
-    _sorts = {
+    _sorts: ClassVar[dict[str, type[dbcore.query.FieldSort]]] = {
         "some_sort": SortFixture,
     }
 
@@ -92,7 +93,7 @@ class DatabaseFixture1(dbcore.Database):
 
 
 class ModelFixture2(ModelFixture1):
-    _fields = {
+    _fields: ClassVar[dict[str, dbcore.types.Type]] = {
         "id": dbcore.types.PRIMARY_ID,
         "field_one": dbcore.types.INTEGER,
         "field_two": dbcore.types.INTEGER,
@@ -104,7 +105,7 @@ class DatabaseFixture2(dbcore.Database):
 
 
 class ModelFixture3(ModelFixture1):
-    _fields = {
+    _fields: ClassVar[dict[str, dbcore.types.Type]] = {
         "id": dbcore.types.PRIMARY_ID,
         "field_one": dbcore.types.INTEGER,
         "field_two": dbcore.types.INTEGER,
@@ -117,7 +118,7 @@ class DatabaseFixture3(dbcore.Database):
 
 
 class ModelFixture4(ModelFixture1):
-    _fields = {
+    _fields: ClassVar[dict[str, dbcore.types.Type]] = {
         "id": dbcore.types.PRIMARY_ID,
         "field_one": dbcore.types.INTEGER,
         "field_two": dbcore.types.INTEGER,
@@ -133,14 +134,14 @@ class DatabaseFixture4(dbcore.Database):
 class AnotherModelFixture(ModelFixture1):
     _table = "another"
     _flex_table = "anotherflex"
-    _fields = {
+    _fields: ClassVar[dict[str, dbcore.types.Type]] = {
         "id": dbcore.types.PRIMARY_ID,
         "foo": dbcore.types.INTEGER,
     }
 
 
 class ModelFixture5(ModelFixture1):
-    _fields = {
+    _fields: ClassVar[dict[str, dbcore.types.Type]] = {
         "some_string_field": dbcore.types.STRING,
         "some_float_field": dbcore.types.FLOAT,
         "some_boolean_field": dbcore.types.BOOLEAN,

test/test_plugins.py

@@ -19,6 +19,7 @@ import logging
 import os
 import pkgutil
 import sys
+from typing import ClassVar
 from unittest.mock import ANY, Mock, patch
 
 import pytest
@@ -46,7 +47,7 @@ from beets.util import PromptChoice, displayable_path, syspath
 
 class TestPluginRegistration(PluginTestCase):
     class RatingPlugin(plugins.BeetsPlugin):
-        item_types = {
+        item_types: ClassVar[dict[str, types.Type]] = {
             "rating": types.Float(),
             "multi_value": types.MULTI_VALUE_DSV,
         }
@@ -70,7 +71,9 @@ class TestPluginRegistration(PluginTestCase):
 
     def test_duplicate_type(self):
         class DuplicateTypePlugin(plugins.BeetsPlugin):
-            item_types = {"rating": types.INTEGER}
+            item_types: ClassVar[dict[str, types.Type]] = {
+                "rating": types.INTEGER
+            }
 
         self.register_plugin(DuplicateTypePlugin)
         with pytest.raises(