diff --git a/beets/test/_common.py b/beets/test/_common.py
index 2be33de95..790ea9422 100644
--- a/beets/test/_common.py
+++ b/beets/test/_common.py
@@ -15,7 +15,6 @@
 """Some common functionality for beets' test cases."""
 
 import os
-import shutil
 import sys
 import tempfile
 import unittest
@@ -185,70 +184,6 @@ class Assertions:
         )
 
 
-# A test harness for all beets tests.
-# Provides temporary, isolated configuration.
-class TestCase(unittest.TestCase, Assertions):
-    """A unittest.TestCase subclass that saves and restores beets'
-    global configuration. This allows tests to make temporary
-    modifications that will then be automatically removed when the test
-    completes. Also provides some additional assertion methods, a
-    temporary directory, and a DummyIO.
-    """
-
-    def setUp(self):
-        # A "clean" source list including only the defaults.
-        beets.config.sources = []
-        beets.config.read(user=False, defaults=True)
-
-        # Direct paths to a temporary directory. Tests can also use this
-        # temporary directory.
-        self.temp_dir = util.bytestring_path(tempfile.mkdtemp())
-
-        beets.config["statefile"] = os.fsdecode(
-            os.path.join(self.temp_dir, b"state.pickle")
-        )
-        beets.config["library"] = os.fsdecode(
-            os.path.join(self.temp_dir, b"library.db")
-        )
-        beets.config["directory"] = os.fsdecode(
-            os.path.join(self.temp_dir, b"libdir")
-        )
-
-        # Set $HOME, which is used by Confuse to create directories.
-        self._old_home = os.environ.get("HOME")
-        os.environ["HOME"] = os.fsdecode(self.temp_dir)
-
-        # Initialize, but don't install, a DummyIO.
-        self.io = DummyIO()
-
-    def tearDown(self):
-        if os.path.isdir(syspath(self.temp_dir)):
-            shutil.rmtree(syspath(self.temp_dir))
-        if self._old_home is None:
-            del os.environ["HOME"]
-        else:
-            os.environ["HOME"] = self._old_home
-        self.io.restore()
-
-        beets.config.clear()
-        beets.config._materialized = False
-
-
-class LibTestCase(TestCase):
-    """A test case that includes an in-memory library object (`lib`) and
-    an item added to the library (`i`).
-    """
-
-    def setUp(self):
-        super().setUp()
-        self.lib = beets.library.Library(":memory:")
-        self.i = item(self.lib)
-
-    def tearDown(self):
-        self.lib._connection().close()
-        super().tearDown()
-
-
 # Mock I/O.
 
 
diff --git a/beets/test/helper.py b/beets/test/helper.py
index bd01c0e3a..6cb45e828 100644
--- a/beets/test/helper.py
+++ b/beets/test/helper.py
@@ -36,11 +36,13 @@ import os.path
 import shutil
 import subprocess
 import sys
+import unittest
 from contextlib import contextmanager
 from enum import Enum
 from io import StringIO
 from tempfile import mkdtemp, mkstemp
 from typing import ClassVar
+from unittest.mock import patch
 
 import responses
 from mediafile import Image, MediaFile
@@ -174,11 +176,19 @@ class TestHelper(_common.Assertions):
         Make sure you call ``teardown_beets()`` afterwards.
         """
         self.create_temp_dir()
-        os.environ["BEETSDIR"] = os.fsdecode(self.temp_dir)
+        temp_dir_str = os.fsdecode(self.temp_dir)
+        self.env_patcher = patch.dict(
+            "os.environ",
+            {
+                "BEETSDIR": temp_dir_str,
+                "HOME": temp_dir_str,  # used by Confuse to create directories.
+            },
+        )
+        self.env_patcher.start()
 
         self.config = beets.config
-        self.config.clear()
-        self.config.read()
+        self.config.sources = []
+        self.config.read(user=False, defaults=True)
 
         self.config["plugins"] = []
         self.config["verbose"] = 1
@@ -195,13 +205,16 @@ class TestHelper(_common.Assertions):
             dbpath = ":memory:"
         self.lib = Library(dbpath, self.libdir)
 
+        # Initialize, but don't install, a DummyIO.
+        self.io = _common.DummyIO()
+
     def teardown_beets(self):
+        self.env_patcher.stop()
+        self.io.restore()
         self.lib._close()
-        if "BEETSDIR" in os.environ:
-            del os.environ["BEETSDIR"]
         self.remove_temp_dir()
-        self.config.clear()
-        beets.config.read(user=False, defaults=True)
+        beets.config.clear()
+        beets.config._materialized = False
 
     def load_plugins(self, *plugins):
         """Load and initialize plugins by names.
@@ -490,6 +503,38 @@ class TestHelper(_common.Assertions):
         return path
 
 
+# A test harness for all beets tests.
+# Provides temporary, isolated configuration.
+class BeetsTestCase(unittest.TestCase, TestHelper):
+    """A unittest.TestCase subclass that saves and restores beets'
+    global configuration. This allows tests to make temporary
+    modifications that will then be automatically removed when the test
+    completes. Also provides some additional assertion methods, a
+    temporary directory, and a DummyIO.
+    """
+
+    def setUp(self):
+        self.setup_beets()
+
+    def tearDown(self):
+        self.teardown_beets()
+
+
+class LibTestCase(BeetsTestCase):
+    """A test case that includes an in-memory library object (`lib`) and
+    an item added to the library (`i`).
+    """
+
+    def setUp(self):
+        super().setUp()
+        self.lib = beets.library.Library(":memory:")
+        self.i = _common.item(self.lib)
+
+    def tearDown(self):
+        self.lib._connection().close()
+        super().tearDown()
+
+
 class ImportHelper(TestHelper):
     """Provides tools to setup a library, a directory containing files that are
     to be imported and an import session. The class also provides stubs for the
diff --git a/test/plugins/test_art.py b/test/plugins/test_art.py
index 8a2aa5870..4d631aa38 100644
--- a/test/plugins/test_art.py
+++ b/test/plugins/test_art.py
@@ -26,7 +26,12 @@ import responses
 from beets import config, importer, library, logging, util
 from beets.autotag import AlbumInfo, AlbumMatch
 from beets.test import _common
-from beets.test.helper import CleanupModulesMixin, FetchImageHelper, capture_log
+from beets.test.helper import (
+    BeetsTestCase,
+    CleanupModulesMixin,
+    FetchImageHelper,
+    capture_log,
+)
 from beets.util import syspath
 from beets.util.artresizer import ArtResizer
 from beetsplug import fetchart
@@ -44,7 +49,7 @@ class Settings:
             setattr(self, k, v)
 
 
-class UseThePlugin(CleanupModulesMixin, _common.TestCase):
+class UseThePlugin(CleanupModulesMixin, BeetsTestCase):
     modules = (fetchart.__name__, ArtResizer.__module__)
 
     def setUp(self):
@@ -977,14 +982,14 @@ class ArtForAlbumTest(UseThePlugin):
         self._assert_image_operated(self.IMG_348x348, self.RESIZE_OP, True)
 
 
-class DeprecatedConfigTest(_common.TestCase):
+class DeprecatedConfigTest(BeetsTestCase):
     """While refactoring the plugin, the remote_priority option was deprecated,
     and a new codepath should translate its effect. Check that it actually does
     so.
     """
 
     # If we subclassed UseThePlugin, the configuration change would either be
-    # overwritten by _common.TestCase or be set after constructing the
+    # overwritten by BeetsTestCase or be set after constructing the
     # plugin object
     def setUp(self):
         super().setUp()
@@ -995,7 +1000,7 @@ class DeprecatedConfigTest(_common.TestCase):
         self.assertEqual(type(self.plugin.sources[-1]), fetchart.FileSystem)
 
 
-class EnforceRatioConfigTest(_common.TestCase):
+class EnforceRatioConfigTest(BeetsTestCase):
     """Throw some data at the regexes."""
 
     def _load_with_config(self, values, should_raise):
diff --git a/test/plugins/test_beatport.py b/test/plugins/test_beatport.py
index fd75f2154..9b07ebb0d 100644
--- a/test/plugins/test_beatport.py
+++ b/test/plugins/test_beatport.py
@@ -20,11 +20,11 @@ from datetime import timedelta
 
 from beets import library
 from beets.test import _common
-from beets.test.helper import TestHelper
+from beets.test.helper import BeetsTestCase
 from beetsplug import beatport
 
 
-class BeatportTest(_common.TestCase, TestHelper):
+class BeatportTest(BeetsTestCase):
     def _make_release_response(self):
         """Returns a dict that mimics a response from the beatport API.
 
@@ -601,7 +601,7 @@ class BeatportTest(_common.TestCase, TestHelper):
             self.assertEqual(track.genre, test_track.genre)
 
 
-class BeatportResponseEmptyTest(_common.TestCase, TestHelper):
+class BeatportResponseEmptyTest(BeetsTestCase):
     def _make_tracks_response(self):
         results = [
             {
diff --git a/test/plugins/test_convert.py b/test/plugins/test_convert.py
index bc13b6fec..12b72bf85 100644
--- a/test/plugins/test_convert.py
+++ b/test/plugins/test_convert.py
@@ -22,8 +22,8 @@ import unittest
 from mediafile import MediaFile
 
 from beets import util
-from beets.test import _common, helper
-from beets.test.helper import capture_log, control_stdin
+from beets.test import _common
+from beets.test.helper import BeetsTestCase, capture_log, control_stdin
 from beets.util import bytestring_path, displayable_path
 
 
@@ -33,7 +33,7 @@ def shell_quote(text):
     return shlex.quote(text)
 
 
-class TestHelper(helper.TestHelper):
+class ConvertMixin:
     def tagged_copy_cmd(self, tag):
         """Return a conversion command that copies files and appends
         `tag` to the copy.
@@ -84,8 +84,12 @@ class TestHelper(helper.TestHelper):
             )
 
 
+class ConvertTestCase(BeetsTestCase, ConvertMixin):
+    pass
+
+
 @_common.slow_test()
-class ImportConvertTest(_common.TestCase, TestHelper):
+class ImportConvertTest(ConvertTestCase):
     def setUp(self):
         self.setup_beets(disk=True)  # Converter is threaded
         self.importer = self.create_importer()
@@ -163,7 +167,7 @@ class ConvertCommand:
 
 
 @_common.slow_test()
-class ConvertCliTest(_common.TestCase, TestHelper, ConvertCommand):
+class ConvertCliTest(ConvertTestCase, ConvertCommand):
     def setUp(self):
         self.setup_beets(disk=True)  # Converter is threaded
         self.album = self.add_album_fixture(ext="ogg")
@@ -310,7 +314,7 @@ class ConvertCliTest(_common.TestCase, TestHelper, ConvertCommand):
 
 
 @_common.slow_test()
-class NeverConvertLossyFilesTest(_common.TestCase, TestHelper, ConvertCommand):
+class NeverConvertLossyFilesTest(ConvertTestCase, ConvertCommand):
     """Test the effect of the `never_convert_lossy_files` option."""
 
     def setUp(self):
diff --git a/test/plugins/test_discogs.py b/test/plugins/test_discogs.py
index 6ee57dcd9..203a8a376 100644
--- a/test/plugins/test_discogs.py
+++ b/test/plugins/test_discogs.py
@@ -18,14 +18,13 @@
 import unittest
 
 from beets import config
-from beets.test import _common
 from beets.test._common import Bag
-from beets.test.helper import capture_log
+from beets.test.helper import BeetsTestCase, capture_log
 from beets.util.id_extractors import extract_discogs_id_regex
 from beetsplug.discogs import DiscogsPlugin
 
 
-class DGAlbumInfoTest(_common.TestCase):
+class DGAlbumInfoTest(BeetsTestCase):
     def _make_release(self, tracks=None):
         """Returns a Bag that mimics a discogs_client.Release. The list
         of elements on the returned Bag is incomplete, including just
diff --git a/test/plugins/test_embedart.py b/test/plugins/test_embedart.py
index 48a110295..d280fefd9 100644
--- a/test/plugins/test_embedart.py
+++ b/test/plugins/test_embedart.py
@@ -47,7 +47,6 @@ class EmbedartCliTest(TestHelper, FetchImageHelper):
     abbey_differentpath = os.path.join(_common.RSRC, b"abbey-different.jpg")
 
     def setUp(self):
-        self.io = _common.DummyIO()
         self.io.install()
         self.setup_beets()  # Converter is threaded
         self.load_plugins("embedart")
diff --git a/test/plugins/test_hook.py b/test/plugins/test_hook.py
index 1364028f6..ee79b3599 100644
--- a/test/plugins/test_hook.py
+++ b/test/plugins/test_hook.py
@@ -19,8 +19,7 @@ import tempfile
 import unittest
 
 from beets import config, plugins
-from beets.test import _common
-from beets.test.helper import TestHelper, capture_log
+from beets.test.helper import BeetsTestCase, capture_log
 
 
 def get_temporary_path():
@@ -30,7 +29,7 @@ def get_temporary_path():
     return os.path.join(temporary_directory, temporary_name)
 
 
-class HookTest(_common.TestCase, TestHelper):
+class HookTest(BeetsTestCase):
     TEST_HOOK_COUNT = 5
 
     def setUp(self):
diff --git a/test/plugins/test_plugin_mediafield.py b/test/plugins/test_plugin_mediafield.py
index 0e03886cf..938f1244b 100644
--- a/test/plugins/test_plugin_mediafield.py
+++ b/test/plugins/test_plugin_mediafield.py
@@ -24,6 +24,7 @@ import mediafile
 from beets.library import Item
 from beets.plugins import BeetsPlugin
 from beets.test import _common
+from beets.test.helper import BeetsTestCase
 from beets.util import bytestring_path, syspath
 
 field_extension = mediafile.MediaField(
@@ -41,7 +42,7 @@ list_field_extension = mediafile.ListMediaField(
 )
 
 
-class ExtendedFieldTestMixin(_common.TestCase):
+class ExtendedFieldTestMixin(BeetsTestCase):
     def _mediafile_fixture(self, name, extension="mp3"):
         name = bytestring_path(name + "." + extension)
         src = os.path.join(_common.RSRC, name)
diff --git a/test/plugins/test_smartplaylist.py b/test/plugins/test_smartplaylist.py
index 68c11c910..9655f3f90 100644
--- a/test/plugins/test_smartplaylist.py
+++ b/test/plugins/test_smartplaylist.py
@@ -23,14 +23,13 @@ from beets import config
 from beets.dbcore import OrQuery
 from beets.dbcore.query import FixedFieldSort, MultipleSort, NullSort
 from beets.library import Album, Item, parse_query_string
-from beets.test import _common
-from beets.test.helper import TestHelper
+from beets.test.helper import BeetsTestCase
 from beets.ui import UserError
 from beets.util import CHAR_REPLACE, bytestring_path, syspath
 from beetsplug.smartplaylist import SmartPlaylistPlugin
 
 
-class SmartPlaylistTest(_common.TestCase):
+class SmartPlaylistTest(BeetsTestCase):
     def test_build_queries(self):
         spl = SmartPlaylistPlugin()
         self.assertIsNone(spl._matched_playlists)
@@ -339,7 +338,7 @@ class SmartPlaylistTest(_common.TestCase):
         self.assertEqual(content, b"http://beets:8337/item/3/file\n")
 
 
-class SmartPlaylistCLITest(_common.TestCase, TestHelper):
+class SmartPlaylistCLITest(BeetsTestCase):
     def setUp(self):
         self.setup_beets()
 
diff --git a/test/plugins/test_spotify.py b/test/plugins/test_spotify.py
index ae5ce5228..c2fcc0722 100644
--- a/test/plugins/test_spotify.py
+++ b/test/plugins/test_spotify.py
@@ -9,7 +9,7 @@ import responses
 from beets import config
 from beets.library import Item
 from beets.test import _common
-from beets.test.helper import TestHelper
+from beets.test.helper import BeetsTestCase
 from beetsplug import spotify
 
 
@@ -25,7 +25,7 @@ def _params(url):
     return parse_qs(urlparse(url).query)
 
 
-class SpotifyPluginTest(_common.TestCase, TestHelper):
+class SpotifyPluginTest(BeetsTestCase):
     @responses.activate
     def setUp(self):
         config.clear()
diff --git a/test/plugins/test_subsonicupdate.py b/test/plugins/test_subsonicupdate.py
index 3f84d848f..be7f979ac 100644
--- a/test/plugins/test_subsonicupdate.py
+++ b/test/plugins/test_subsonicupdate.py
@@ -6,8 +6,7 @@ from urllib.parse import parse_qs, urlparse
 import responses
 
 from beets import config
-from beets.test import _common
-from beets.test.helper import TestHelper
+from beets.test.helper import BeetsTestCase
 from beetsplug import subsonicupdate
 
 
@@ -26,7 +25,7 @@ def _params(url):
     return parse_qs(urlparse(url).query)
 
 
-class SubsonicPluginTest(_common.TestCase, TestHelper):
+class SubsonicPluginTest(BeetsTestCase):
     """Test class for subsonicupdate."""
 
     @responses.activate
diff --git a/test/plugins/test_the.py b/test/plugins/test_the.py
index e6d510774..4f23d6f13 100644
--- a/test/plugins/test_the.py
+++ b/test/plugins/test_the.py
@@ -3,11 +3,11 @@
 import unittest
 
 from beets import config
-from beets.test import _common
+from beets.test.helper import BeetsTestCase
 from beetsplug.the import FORMAT, PATTERN_A, PATTERN_THE, ThePlugin
 
 
-class ThePluginTest(_common.TestCase):
+class ThePluginTest(BeetsTestCase):
     def test_unthe_with_default_patterns(self):
         self.assertEqual(ThePlugin().unthe("", PATTERN_THE), "")
         self.assertEqual(
diff --git a/test/plugins/test_web.py b/test/plugins/test_web.py
index afd1ed706..c34de05d2 100644
--- a/test/plugins/test_web.py
+++ b/test/plugins/test_web.py
@@ -9,10 +9,11 @@ import unittest
 from beets import logging
 from beets.library import Album, Item
 from beets.test import _common
+from beets.test.helper import LibTestCase
 from beetsplug import web
 
 
-class WebPluginTest(_common.LibTestCase):
+class WebPluginTest(LibTestCase):
     def setUp(self):
         super().setUp()
         self.log = logging.getLogger("beets.web")
diff --git a/test/test_art_resize.py b/test/test_art_resize.py
index ac9463cba..e7bee02dc 100644
--- a/test/test_art_resize.py
+++ b/test/test_art_resize.py
@@ -20,7 +20,7 @@ import unittest
 from unittest.mock import patch
 
 from beets.test import _common
-from beets.test.helper import CleanupModulesMixin, TestHelper
+from beets.test.helper import BeetsTestCase, CleanupModulesMixin
 from beets.util import command_output, syspath
 from beets.util.artresizer import IMBackend, PILBackend
 
@@ -48,7 +48,7 @@ class DummyPILBackend(PILBackend):
         pass
 
 
-class ArtResizerFileSizeTest(CleanupModulesMixin, _common.TestCase, TestHelper):
+class ArtResizerFileSizeTest(CleanupModulesMixin, BeetsTestCase):
     """Unittest test case for Art Resizer to a specific filesize."""
 
     modules = (IMBackend.__module__,)
diff --git a/test/test_autotag.py b/test/test_autotag.py
index e9b44458c..8ff613cff 100644
--- a/test/test_autotag.py
+++ b/test/test_autotag.py
@@ -22,11 +22,11 @@ from beets import autotag, config
 from beets.autotag import AlbumInfo, TrackInfo, match
 from beets.autotag.hooks import Distance, string_dist
 from beets.library import Item
-from beets.test import _common
+from beets.test.helper import BeetsTestCase
 from beets.util import plurality
 
 
-class PluralityTest(_common.TestCase):
+class PluralityTest(BeetsTestCase):
     def test_plurality_consensus(self):
         objs = [1, 1, 1, 1]
         obj, freq = plurality(objs)
@@ -146,7 +146,7 @@ def _clear_weights():
     Distance.__dict__["_weights"].cache = {}
 
 
-class DistanceTest(_common.TestCase):
+class DistanceTest(BeetsTestCase):
     def tearDown(self):
         super().tearDown()
         _clear_weights()
@@ -330,7 +330,7 @@ class DistanceTest(_common.TestCase):
         )
 
 
-class TrackDistanceTest(_common.TestCase):
+class TrackDistanceTest(BeetsTestCase):
     def test_identical_tracks(self):
         item = _make_item("one", 1)
         info = _make_trackinfo()[0]
@@ -358,7 +358,7 @@ class TrackDistanceTest(_common.TestCase):
         self.assertEqual(dist, 0.0)
 
 
-class AlbumDistanceTest(_common.TestCase):
+class AlbumDistanceTest(BeetsTestCase):
     def _mapping(self, items, info):
         out = {}
         for i, t in zip(items, info.tracks):
@@ -664,7 +664,7 @@ class ApplyTestUtil:
         autotag.apply_metadata(info, mapping)
 
 
-class ApplyTest(_common.TestCase, ApplyTestUtil):
+class ApplyTest(BeetsTestCase, ApplyTestUtil):
     def setUp(self):
         super().setUp()
 
@@ -925,7 +925,7 @@ class ApplyTest(_common.TestCase, ApplyTestUtil):
         self.assertEqual(self.items[0].data_source, "MusicBrainz")
 
 
-class ApplyCompilationTest(_common.TestCase, ApplyTestUtil):
+class ApplyCompilationTest(BeetsTestCase, ApplyTestUtil):
     def setUp(self):
         super().setUp()
 
@@ -1073,7 +1073,7 @@ class StringDistanceTest(unittest.TestCase):
         self.assertEqual(dist, 0.0)
 
 
-class EnumTest(_common.TestCase):
+class EnumTest(BeetsTestCase):
     """
     Test Enum Subclasses defined in beets.util.enumeration
     """
diff --git a/test/test_datequery.py b/test/test_datequery.py
index 2b666f0d1..56c85e05d 100644
--- a/test/test_datequery.py
+++ b/test/test_datequery.py
@@ -25,7 +25,7 @@ from beets.dbcore.query import (
     InvalidQueryArgumentValueError,
     _parse_periods,
 )
-from beets.test import _common
+from beets.test.helper import LibTestCase
 
 
 def _date(string):
@@ -152,7 +152,7 @@ def _parsetime(s):
     return time.mktime(datetime.strptime(s, "%Y-%m-%d %H:%M").timetuple())
 
 
-class DateQueryTest(_common.LibTestCase):
+class DateQueryTest(LibTestCase):
     def setUp(self):
         super().setUp()
         self.i.added = _parsetime("2013-03-30 22:21")
@@ -187,7 +187,7 @@ class DateQueryTest(_common.LibTestCase):
         self.assertEqual(len(matched), 0)
 
 
-class DateQueryTestRelative(_common.LibTestCase):
+class DateQueryTestRelative(LibTestCase):
     def setUp(self):
         super().setUp()
 
@@ -233,7 +233,7 @@ class DateQueryTestRelative(_common.LibTestCase):
         self.assertEqual(len(matched), 0)
 
 
-class DateQueryTestRelativeMore(_common.LibTestCase):
+class DateQueryTestRelativeMore(LibTestCase):
     def setUp(self):
         super().setUp()
         self.i.added = _parsetime(datetime.now().strftime("%Y-%m-%d %H:%M"))
diff --git a/test/test_files.py b/test/test_files.py
index 46aebe54f..68971cd85 100644
--- a/test/test_files.py
+++ b/test/test_files.py
@@ -25,10 +25,11 @@ import beets.library
 from beets import util
 from beets.test import _common
 from beets.test._common import item, touch
+from beets.test.helper import BeetsTestCase
 from beets.util import MoveOperation, bytestring_path, syspath
 
 
-class MoveTest(_common.TestCase):
+class MoveTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -207,7 +208,7 @@ class MoveTest(_common.TestCase):
         self.assertEqual(self.i.path, util.normpath(self.dest))
 
 
-class HelperTest(_common.TestCase):
+class HelperTest(BeetsTestCase):
     def test_ancestry_works_on_file(self):
         p = "/a/b/c"
         a = ["/", "/a", "/a/b"]
@@ -244,7 +245,7 @@ class HelperTest(_common.TestCase):
         self.assertEqual(util.path_as_posix(p), a)
 
 
-class AlbumFileTest(_common.TestCase):
+class AlbumFileTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -311,7 +312,7 @@ class AlbumFileTest(_common.TestCase):
         self.assertIn(b"testotherdir", self.i.path)
 
 
-class ArtFileTest(_common.TestCase):
+class ArtFileTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -485,7 +486,7 @@ class ArtFileTest(_common.TestCase):
         self.assertExists(oldartpath)
 
 
-class RemoveTest(_common.TestCase):
+class RemoveTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -546,7 +547,7 @@ class RemoveTest(_common.TestCase):
 
 
 # Tests that we can "delete" nonexistent files.
-class SoftRemoveTest(_common.TestCase):
+class SoftRemoveTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -564,7 +565,7 @@ class SoftRemoveTest(_common.TestCase):
             self.fail("OSError when removing path")
 
 
-class SafeMoveCopyTest(_common.TestCase):
+class SafeMoveCopyTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -612,7 +613,7 @@ class SafeMoveCopyTest(_common.TestCase):
         self.assertExists(self.path)
 
 
-class PruneTest(_common.TestCase):
+class PruneTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -632,7 +633,7 @@ class PruneTest(_common.TestCase):
         self.assertNotExists(self.sub)
 
 
-class WalkTest(_common.TestCase):
+class WalkTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -666,7 +667,7 @@ class WalkTest(_common.TestCase):
         self.assertEqual(res[0], (self.base, [], []))
 
 
-class UniquePathTest(_common.TestCase):
+class UniquePathTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -694,7 +695,7 @@ class UniquePathTest(_common.TestCase):
         self.assertEqual(path, os.path.join(self.base, b"x.3.mp3"))
 
 
-class MkDirAllTest(_common.TestCase):
+class MkDirAllTest(BeetsTestCase):
     def test_parent_exists(self):
         path = os.path.join(self.temp_dir, b"foo", b"bar", b"baz", b"qux.mp3")
         util.mkdirall(path)
diff --git a/test/test_importer.py b/test/test_importer.py
index 87af62a71..8c2b474e0 100644
--- a/test/test_importer.py
+++ b/test/test_importer.py
@@ -36,6 +36,7 @@ from beets.importer import albums_in_dir
 from beets.test import _common
 from beets.test.helper import (
     AutotagStub,
+    BeetsTestCase,
     ImportHelper,
     TestHelper,
     capture_log,
@@ -44,7 +45,7 @@ from beets.test.helper import (
 from beets.util import bytestring_path, displayable_path, syspath
 
 
-class ScrubbedImportTest(_common.TestCase, ImportHelper):
+class ScrubbedImportTest(BeetsTestCase, ImportHelper):
     def setUp(self):
         self.setup_beets(disk=True)
         self.load_plugins("scrub")
@@ -99,7 +100,7 @@ class ScrubbedImportTest(_common.TestCase, ImportHelper):
 
 
 @_common.slow_test()
-class NonAutotaggedImportTest(_common.TestCase, ImportHelper):
+class NonAutotaggedImportTest(BeetsTestCase, ImportHelper):
     def setUp(self):
         self.setup_beets(disk=True)
         self._create_import_dir(2)
@@ -344,7 +345,7 @@ class ImportPasswordRarTest(ImportZipTest):
         return os.path.join(_common.RSRC, b"password.rar")
 
 
-class ImportSingletonTest(_common.TestCase, ImportHelper):
+class ImportSingletonTest(BeetsTestCase, ImportHelper):
     """Test ``APPLY`` and ``ASIS`` choices for an import session with
     singletons config set to True.
     """
@@ -467,7 +468,7 @@ class ImportSingletonTest(_common.TestCase, ImportHelper):
             self.assertEqual(item.title, "Applied Title 1 - formatted")
 
 
-class ImportTest(_common.TestCase, ImportHelper):
+class ImportTest(BeetsTestCase, ImportHelper):
     """Test APPLY, ASIS and SKIP choices."""
 
     def setUp(self):
@@ -681,7 +682,7 @@ class ImportTest(_common.TestCase, ImportHelper):
                 )
 
 
-class ImportTracksTest(_common.TestCase, ImportHelper):
+class ImportTracksTest(BeetsTestCase, ImportHelper):
     """Test TRACKS and APPLY choice."""
 
     def setUp(self):
@@ -715,7 +716,7 @@ class ImportTracksTest(_common.TestCase, ImportHelper):
         self.assert_file_in_lib(b"singletons", b"Applied Title 1.mp3")
 
 
-class ImportCompilationTest(_common.TestCase, ImportHelper):
+class ImportCompilationTest(BeetsTestCase, ImportHelper):
     """Test ASIS import of a folder containing tracks with different artists."""
 
     def setUp(self):
@@ -834,7 +835,7 @@ class ImportCompilationTest(_common.TestCase, ImportHelper):
         self.assertTrue(asserted_multi_artists_0 and asserted_multi_artists_1)
 
 
-class ImportExistingTest(_common.TestCase, ImportHelper):
+class ImportExistingTest(BeetsTestCase, ImportHelper):
     """Test importing files that are already in the library directory."""
 
     def setUp(self):
@@ -959,7 +960,7 @@ class ImportExistingTest(_common.TestCase, ImportHelper):
         self.assertNotExists(self.import_media[0].path)
 
 
-class GroupAlbumsImportTest(_common.TestCase, ImportHelper):
+class GroupAlbumsImportTest(BeetsTestCase, ImportHelper):
     def setUp(self):
         self.setup_beets()
         self._create_import_dir(3)
@@ -1031,7 +1032,7 @@ class GlobalGroupAlbumsImportTest(GroupAlbumsImportTest):
         config["import"]["group_albums"] = True
 
 
-class ChooseCandidateTest(_common.TestCase, ImportHelper):
+class ChooseCandidateTest(BeetsTestCase, ImportHelper):
     def setUp(self):
         self.setup_beets()
         self._create_import_dir(1)
@@ -1054,7 +1055,7 @@ class ChooseCandidateTest(_common.TestCase, ImportHelper):
         self.assertEqual(self.lib.albums().get().album, "Applied Album MM")
 
 
-class InferAlbumDataTest(_common.TestCase):
+class InferAlbumDataTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -1365,7 +1366,7 @@ class ImportDuplicateSingletonTest(unittest.TestCase, TestHelper):
         return item
 
 
-class TagLogTest(_common.TestCase):
+class TagLogTest(BeetsTestCase):
     def test_tag_log_line(self):
         sio = StringIO()
         handler = logging.StreamHandler(sio)
@@ -1484,7 +1485,7 @@ def _mkmp3(path):
     )
 
 
-class AlbumsInDirTest(_common.TestCase):
+class AlbumsInDirTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -1526,7 +1527,7 @@ class AlbumsInDirTest(_common.TestCase):
                 self.assertEqual(len(album), 1)
 
 
-class MultiDiscAlbumsInDirTest(_common.TestCase):
+class MultiDiscAlbumsInDirTest(BeetsTestCase):
     def create_music(self, files=True, ascii=True):
         """Create some music in multiple album directories.
 
@@ -1751,7 +1752,7 @@ class ReimportTest(unittest.TestCase, ImportHelper):
         self.assertEqual(self._album().data_source, "match_source")
 
 
-class ImportPretendTest(_common.TestCase, ImportHelper):
+class ImportPretendTest(BeetsTestCase, ImportHelper):
     """Test the pretend commandline option"""
 
     def __init__(self, method_name="runTest"):
@@ -1944,7 +1945,7 @@ def mocked_get_recording_by_id(
     "musicbrainzngs.get_release_by_id",
     Mock(side_effect=mocked_get_release_by_id),
 )
-class ImportMusicBrainzIdTest(_common.TestCase, ImportHelper):
+class ImportMusicBrainzIdTest(BeetsTestCase, ImportHelper):
     """Test the --musicbrainzid argument."""
 
     MB_RELEASE_PREFIX = "https://musicbrainz.org/release/"
diff --git a/test/test_library.py b/test/test_library.py
index c9d0440b5..179927dc9 100644
--- a/test/test_library.py
+++ b/test/test_library.py
@@ -32,14 +32,14 @@ import beets.library
 from beets import config, plugins, util
 from beets.test import _common
 from beets.test._common import item
-from beets.test.helper import TestHelper
+from beets.test.helper import BeetsTestCase, LibTestCase, TestHelper
 from beets.util import bytestring_path, syspath
 
 # Shortcut to path normalization.
 np = util.normpath
 
 
-class LoadTest(_common.LibTestCase):
+class LoadTest(LibTestCase):
     def test_load_restores_data_from_db(self):
         original_title = self.i.title
         self.i.title = "something"
@@ -53,7 +53,7 @@ class LoadTest(_common.LibTestCase):
         self.assertNotIn("artist", self.i._dirty)
 
 
-class StoreTest(_common.LibTestCase):
+class StoreTest(LibTestCase):
     def test_store_changes_database_value(self):
         self.i.year = 1987
         self.i.store()
@@ -94,7 +94,7 @@ class StoreTest(_common.LibTestCase):
         self.assertNotIn("flex1", album.items()[0])
 
 
-class AddTest(_common.TestCase):
+class AddTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.lib = beets.library.Library(":memory:")
@@ -126,14 +126,14 @@ class AddTest(_common.TestCase):
         self.assertEqual(new_grouping, self.i.grouping)
 
 
-class RemoveTest(_common.LibTestCase):
+class RemoveTest(LibTestCase):
     def test_remove_deletes_from_db(self):
         self.i.remove()
         c = self.lib._connection().execute("select * from items")
         self.assertIsNone(c.fetchone())
 
 
-class GetSetTest(_common.TestCase):
+class GetSetTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.i = item()
@@ -169,7 +169,7 @@ class GetSetTest(_common.TestCase):
         self.assertIsNone(i.get("flexx"))
 
 
-class DestinationTest(_common.TestCase):
+class DestinationTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         # default directory is ~/Music and the only reason why it was switched
@@ -182,10 +182,6 @@ class DestinationTest(_common.TestCase):
         super().tearDown()
         self.lib._connection().close()
 
-        # Reset config if it was changed in test cases
-        config.clear()
-        config.read(user=False, defaults=True)
-
     def test_directory_works_with_trailing_slash(self):
         self.lib.directory = b"one/"
         self.lib.path_formats = [("default", "two")]
@@ -551,7 +547,7 @@ class DestinationTest(_common.TestCase):
         self.assertEqual(self.i.destination(), np("one/foo/two"))
 
 
-class ItemFormattedMappingTest(_common.LibTestCase):
+class ItemFormattedMappingTest(LibTestCase):
     def test_formatted_item_value(self):
         formatted = self.i.formatted()
         self.assertEqual(formatted["artist"], "the artist")
@@ -624,7 +620,7 @@ class PathFormattingMixin:
         self.assertEqual(actual, dest)
 
 
-class DestinationFunctionTest(_common.TestCase, PathFormattingMixin):
+class DestinationFunctionTest(BeetsTestCase, PathFormattingMixin):
     def setUp(self):
         super().setUp()
         self.lib = beets.library.Library(":memory:")
@@ -733,7 +729,7 @@ class DestinationFunctionTest(_common.TestCase, PathFormattingMixin):
         self._assert_dest(b"/base/Alice & Bob")
 
 
-class DisambiguationTest(_common.TestCase, PathFormattingMixin):
+class DisambiguationTest(BeetsTestCase, PathFormattingMixin):
     def setUp(self):
         super().setUp()
         self.lib = beets.library.Library(":memory:")
@@ -822,7 +818,7 @@ class DisambiguationTest(_common.TestCase, PathFormattingMixin):
         self._assert_dest(b"/base/foo/the title", self.i1)
 
 
-class SingletonDisambiguationTest(_common.TestCase, PathFormattingMixin):
+class SingletonDisambiguationTest(BeetsTestCase, PathFormattingMixin):
     def setUp(self):
         super().setUp()
         self.lib = beets.library.Library(":memory:")
@@ -907,7 +903,7 @@ class SingletonDisambiguationTest(_common.TestCase, PathFormattingMixin):
         self._assert_dest(b"/base/foo/the title", self.i1)
 
 
-class PluginDestinationTest(_common.TestCase):
+class PluginDestinationTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -959,7 +955,7 @@ class PluginDestinationTest(_common.TestCase):
         self._assert_dest(b"the artist bar_baz")
 
 
-class AlbumInfoTest(_common.TestCase):
+class AlbumInfoTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.lib = beets.library.Library(":memory:")
@@ -1064,7 +1060,7 @@ class AlbumInfoTest(_common.TestCase):
         self.assertEqual(i.album, ai.album)
 
 
-class ArtDestinationTest(_common.TestCase):
+class ArtDestinationTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         config["art_filename"] = "artimage"
@@ -1092,7 +1088,7 @@ class ArtDestinationTest(_common.TestCase):
         self.assertIn(b"artYimage", art)
 
 
-class PathStringTest(_common.TestCase):
+class PathStringTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.lib = beets.library.Library(":memory:")
@@ -1178,7 +1174,7 @@ class PathStringTest(_common.TestCase):
         self.assertTrue(isinstance(alb.artpath, bytes))
 
 
-class MtimeTest(_common.TestCase):
+class MtimeTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.ipath = os.path.join(self.temp_dir, b"testfile.mp3")
@@ -1216,7 +1212,7 @@ class MtimeTest(_common.TestCase):
         self.assertGreaterEqual(self.i.mtime, self._mtime())
 
 
-class ImportTimeTest(_common.TestCase):
+class ImportTimeTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.lib = beets.library.Library(":memory:")
@@ -1232,7 +1228,7 @@ class ImportTimeTest(_common.TestCase):
         self.assertGreater(self.singleton.added, 0)
 
 
-class TemplateTest(_common.LibTestCase):
+class TemplateTest(LibTestCase):
     def test_year_formatted_in_template(self):
         self.i.year = 123
         self.i.store()
@@ -1262,7 +1258,7 @@ class TemplateTest(_common.LibTestCase):
         self.assertEqual(f"{item:$tagada}", "togodo")
 
 
-class UnicodePathTest(_common.LibTestCase):
+class UnicodePathTest(LibTestCase):
     def test_unicode_path(self):
         self.i.path = os.path.join(_common.RSRC, "unicode\u2019d.mp3".encode())
         # If there are any problems with unicode paths, we will raise
diff --git a/test/test_logging.py b/test/test_logging.py
index 58be799e0..db7f33bfd 100644
--- a/test/test_logging.py
+++ b/test/test_logging.py
@@ -10,10 +10,10 @@ import beets.logging as blog
 import beetsplug
 from beets import plugins, ui
 from beets.test import _common, helper
-from beets.test._common import TestCase
+from beets.test.helper import BeetsTestCase
 
 
-class LoggingTest(TestCase):
+class LoggingTest(BeetsTestCase):
     def test_logging_management(self):
         l1 = log.getLogger("foo123")
         l2 = blog.getLogger("foo123")
@@ -162,7 +162,7 @@ class LoggingLevelTest(unittest.TestCase, helper.TestHelper):
 
 
 @_common.slow_test()
-class ConcurrentEventsTest(TestCase, helper.TestHelper):
+class ConcurrentEventsTest(BeetsTestCase):
     """Similar to LoggingLevelTest but lower-level and focused on multiple
     events interaction. Since this is a bit heavy we don't do it in
     LoggingLevelTest.
diff --git a/test/test_mb.py b/test/test_mb.py
index efd620522..9922cbfa0 100644
--- a/test/test_mb.py
+++ b/test/test_mb.py
@@ -20,10 +20,10 @@ from unittest import mock
 
 from beets import config
 from beets.autotag import mb
-from beets.test import _common
+from beets.test.helper import BeetsTestCase
 
 
-class MBAlbumInfoTest(_common.TestCase):
+class MBAlbumInfoTest(BeetsTestCase):
     def _make_release(
         self,
         date_str="2009",
@@ -662,7 +662,7 @@ class MBAlbumInfoTest(_common.TestCase):
         self.assertEqual(t[1].trackdisambig, "SECOND TRACK")
 
 
-class ParseIDTest(_common.TestCase):
+class ParseIDTest(BeetsTestCase):
     def test_parse_id_correct(self):
         id_string = "28e32c71-1450-463e-92bf-e0a46446fc11"
         out = mb._parse_id(id_string)
@@ -680,7 +680,7 @@ class ParseIDTest(_common.TestCase):
         self.assertEqual(out, id_string)
 
 
-class ArtistFlatteningTest(_common.TestCase):
+class ArtistFlatteningTest(BeetsTestCase):
     def _credit_dict(self, suffix=""):
         return {
             "artist": {
diff --git a/test/test_metasync.py b/test/test_metasync.py
index 9dae099af..a3bc3acb2 100644
--- a/test/test_metasync.py
+++ b/test/test_metasync.py
@@ -21,7 +21,7 @@ from datetime import datetime
 
 from beets.library import Item
 from beets.test import _common
-from beets.test.helper import TestHelper
+from beets.test.helper import BeetsTestCase
 
 
 def _parsetime(s):
@@ -32,7 +32,7 @@ def _is_windows():
     return platform.system() == "Windows"
 
 
-class MetaSyncTest(_common.TestCase, TestHelper):
+class MetaSyncTest(BeetsTestCase):
     itunes_library_unix = os.path.join(_common.RSRC, b"itunes_library_unix.xml")
     itunes_library_windows = os.path.join(
         _common.RSRC, b"itunes_library_windows.xml"
diff --git a/test/test_query.py b/test/test_query.py
index 69277cfcd..897b247dc 100644
--- a/test/test_query.py
+++ b/test/test_query.py
@@ -31,6 +31,7 @@ from beets.dbcore.query import (
 )
 from beets.library import Item, Library
 from beets.test import _common, helper
+from beets.test.helper import BeetsTestCase, LibTestCase
 from beets.util import syspath
 
 # Because the absolute path begins with something like C:, we
@@ -48,7 +49,7 @@ class TestHelper(helper.TestHelper):
         self.assertNotIn(item.id, result_ids)
 
 
-class AnyFieldQueryTest(_common.LibTestCase):
+class AnyFieldQueryTest(LibTestCase):
     def test_no_restriction(self):
         q = dbcore.query.AnyFieldQuery(
             "title",
@@ -92,7 +93,7 @@ class AssertsMixin:
 
 # A test case class providing a library with some dummy data and some
 # assertions involving that data.
-class DummyDataTestCase(_common.TestCase, AssertsMixin):
+class DummyDataTestCase(BeetsTestCase, AssertsMixin):
     def setUp(self):
         super().setUp()
         self.lib = beets.library.Library(":memory:")
@@ -418,7 +419,7 @@ class GetTest(DummyDataTestCase):
         self.assertIsInstance(raised.exception, ParsingError)
 
 
-class MatchTest(_common.TestCase):
+class MatchTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.item = _common.item()
@@ -487,7 +488,7 @@ class MatchTest(_common.TestCase):
         self.assertNotEqual(q3, q4)
 
 
-class PathQueryTest(_common.LibTestCase, TestHelper, AssertsMixin):
+class PathQueryTest(LibTestCase, TestHelper, AssertsMixin):
     def setUp(self):
         super().setUp()
 
@@ -871,7 +872,7 @@ class NoneQueryTest(unittest.TestCase, TestHelper):
         self.assertInResult(item, matched)
 
 
-class NotQueryMatchTest(_common.TestCase):
+class NotQueryMatchTest(BeetsTestCase):
     """Test `query.NotQuery` matching against a single item, using the same
     cases and assertions as on `MatchTest`, plus assertion on the negated
     queries (ie. assertTrue(q) -> assertFalse(NotQuery(q))).
@@ -1129,7 +1130,7 @@ class NotQueryTest(DummyDataTestCase):
                 pass
 
 
-class RelatedQueriesTest(_common.TestCase, AssertsMixin):
+class RelatedQueriesTest(BeetsTestCase, AssertsMixin):
     """Test album-level queries with track-level filters and vice-versa."""
 
     def setUp(self):
diff --git a/test/test_sort.py b/test/test_sort.py
index 52fa02600..b222c93f9 100644
--- a/test/test_sort.py
+++ b/test/test_sort.py
@@ -20,11 +20,12 @@ import unittest
 import beets.library
 from beets import config, dbcore
 from beets.test import _common
+from beets.test.helper import BeetsTestCase
 
 
 # A test case class providing a library with some dummy data and some
 # assertions involving that data.
-class DummyDataTestCase(_common.TestCase):
+class DummyDataTestCase(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.lib = beets.library.Library(":memory:")
@@ -373,7 +374,7 @@ class ConfigSortTest(DummyDataTestCase):
         self.assertGreater(results[0].albumartist, results[1].albumartist)
 
 
-class CaseSensitivityTest(DummyDataTestCase, _common.TestCase):
+class CaseSensitivityTest(DummyDataTestCase, BeetsTestCase):
     """If case_insensitive is false, lower-case values should be placed
     after all upper-case values. E.g., `Foo Qux bar`
     """
diff --git a/test/test_ui.py b/test/test_ui.py
index 4b37c73df..9ca68992a 100644
--- a/test/test_ui.py
+++ b/test/test_ui.py
@@ -31,6 +31,7 @@ from beets import autotag, config, library, plugins, ui, util
 from beets.autotag.match import distance
 from beets.test import _common
 from beets.test.helper import (
+    BeetsTestCase,
     TestHelper,
     capture_stdout,
     control_stdin,
@@ -108,7 +109,7 @@ class ListTest(unittest.TestCase):
         self.assertNotIn("the album", stdout.getvalue())
 
 
-class RemoveTest(_common.TestCase, TestHelper):
+class RemoveTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -454,7 +455,7 @@ class WriteTest(unittest.TestCase, TestHelper):
         self.assertIn(f"{old_title} -> new title", output)
 
 
-class MoveTest(_common.TestCase):
+class MoveTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -562,7 +563,7 @@ class MoveTest(_common.TestCase):
         self.assertNotExists(self.otherdir)
 
 
-class UpdateTest(_common.TestCase):
+class UpdateTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -763,7 +764,7 @@ class UpdateTest(_common.TestCase):
         self.assertNotEqual(item.lyrics, "new lyrics")
 
 
-class PrintTest(_common.TestCase):
+class PrintTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.io.install()
@@ -802,7 +803,7 @@ class PrintTest(_common.TestCase):
                 del os.environ["LC_CTYPE"]
 
 
-class ImportTest(_common.TestCase):
+class ImportTest(BeetsTestCase):
     def test_quiet_timid_disallowed(self):
         config["import"]["quiet"] = True
         config["import"]["timid"] = True
@@ -1145,7 +1146,7 @@ class ConfigTest(unittest.TestCase, TestHelper):
         )
 
 
-class ShowModelChangeTest(_common.TestCase):
+class ShowModelChangeTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.io.install()
@@ -1197,7 +1198,7 @@ class ShowModelChangeTest(_common.TestCase):
         self.assertIn("bar", out)
 
 
-class ShowChangeTest(_common.TestCase):
+class ShowChangeTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.io.install()
@@ -1358,7 +1359,7 @@ class ShowChangeTest(_common.TestCase):
 
 
 @patch("beets.library.Item.try_filesize", Mock(return_value=987))
-class SummarizeItemsTest(_common.TestCase):
+class SummarizeItemsTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         item = library.Item()
@@ -1395,7 +1396,7 @@ class SummarizeItemsTest(_common.TestCase):
         self.assertEqual(summary, "3 items, G 2, F 1, 4kbps, 32:42, 2.9 KiB")
 
 
-class PathFormatTest(_common.TestCase):
+class PathFormatTest(BeetsTestCase):
     def test_custom_paths_prepend(self):
         default_formats = ui.get_path_formats()
 
@@ -1408,7 +1409,7 @@ class PathFormatTest(_common.TestCase):
 
 
 @_common.slow_test()
-class PluginTest(_common.TestCase, TestHelper):
+class PluginTest(BeetsTestCase):
     def test_plugin_command_from_pluginpath(self):
         config["pluginpath"] = [_common.PLUGINPATH]
         config["plugins"] = ["test"]
@@ -1416,7 +1417,7 @@ class PluginTest(_common.TestCase, TestHelper):
 
 
 @_common.slow_test()
-class CompletionTest(_common.TestCase, TestHelper):
+class CompletionTest(BeetsTestCase):
     def test_completion(self):
         # Load plugin commands
         config["pluginpath"] = [_common.PLUGINPATH]
@@ -1652,7 +1653,7 @@ class CommonOptionsParserTest(unittest.TestCase, TestHelper):
         )
 
 
-class EncodingTest(_common.TestCase):
+class EncodingTest(BeetsTestCase):
     """Tests for the `terminal_encoding` config option and our
     `_in_encoding` and `_out_encoding` utility functions.
     """
diff --git a/test/test_ui_commands.py b/test/test_ui_commands.py
index f371a1ab1..dfd8ffad0 100644
--- a/test/test_ui_commands.py
+++ b/test/test_ui_commands.py
@@ -22,11 +22,12 @@ import unittest
 
 from beets import library, ui
 from beets.test import _common
+from beets.test.helper import BeetsTestCase, LibTestCase
 from beets.ui import commands
 from beets.util import syspath
 
 
-class QueryTest(_common.TestCase):
+class QueryTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
 
@@ -87,7 +88,7 @@ class QueryTest(_common.TestCase):
         self.check_do_query(0, 2, album=True, also_items=False)
 
 
-class FieldsTest(_common.LibTestCase):
+class FieldsTest(LibTestCase):
     def setUp(self):
         super().setUp()
 
diff --git a/test/test_ui_init.py b/test/test_ui_init.py
index 77c9c784b..df1f36b97 100644
--- a/test/test_ui_init.py
+++ b/test/test_ui_init.py
@@ -23,10 +23,10 @@ from random import random
 
 from beets import config, ui
 from beets.test import _common
-from beets.test.helper import control_stdin
+from beets.test.helper import BeetsTestCase, LibTestCase, control_stdin
 
 
-class InputMethodsTest(_common.TestCase):
+class InputMethodsTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.io.install()
@@ -90,7 +90,7 @@ class InputMethodsTest(_common.TestCase):
         self.assertEqual(items, ["1", "3"])
 
 
-class InitTest(_common.LibTestCase):
+class InitTest(LibTestCase):
     def setUp(self):
         super().setUp()
 
@@ -129,7 +129,7 @@ class InitTest(_common.LibTestCase):
             self.assertEqual(h, ui.human_seconds(i))
 
 
-class ParentalDirCreation(_common.TestCase):
+class ParentalDirCreation(BeetsTestCase):
     def test_create_yes(self):
         non_exist_path = _common.os.fsdecode(
             os.path.join(self.temp_dir, b"nonexist", str(random()).encode())
diff --git a/test/test_util.py b/test/test_util.py
index d2a7caea0..63de482ff 100644
--- a/test/test_util.py
+++ b/test/test_util.py
@@ -24,6 +24,7 @@ from unittest.mock import Mock, patch
 
 from beets import util
 from beets.test import _common
+from beets.test.helper import BeetsTestCase
 
 
 class UtilTest(unittest.TestCase):
@@ -157,7 +158,7 @@ class UtilTest(unittest.TestCase):
         pass
 
 
-class PathConversionTest(_common.TestCase):
+class PathConversionTest(BeetsTestCase):
     def test_syspath_windows_format(self):
         with _common.platform_windows():
             path = os.path.join("a", "b", "c")
@@ -200,7 +201,7 @@ class PathConversionTest(_common.TestCase):
         self.assertEqual(outpath, "C:\\caf\xe9".encode())
 
 
-class PathTruncationTest(_common.TestCase):
+class PathTruncationTest(BeetsTestCase):
     def test_truncate_bytestring(self):
         with _common.platform_posix():
             p = util.truncate_path(b"abcde/fgh", 4)
diff --git a/test/test_vfs.py b/test/test_vfs.py
index 789356157..939d44f73 100644
--- a/test/test_vfs.py
+++ b/test/test_vfs.py
@@ -18,9 +18,10 @@ import unittest
 
 from beets import library, vfs
 from beets.test import _common
+from beets.test.helper import BeetsTestCase
 
 
-class VFSTest(_common.TestCase):
+class VFSTest(BeetsTestCase):
     def setUp(self):
         super().setUp()
         self.lib = library.Library(