Handle extra_tags the way they used to be handled

beets/util/__init__.py

@@ -803,7 +803,7 @@ def as_string(value: Any) -> str:
         return str(value)
 
 
-def plurality(objs: Sequence[T]) -> tuple[T, int]:
+def plurality(objs: Iterable[T]) -> tuple[T, int]:
     """Given a sequence of hashble objects, returns the object that
     is most common in the set and the its number of appearance. The
     sequence must contain at least one object.

beetsplug/musicbrainz.py

@@ -18,6 +18,7 @@ from __future__ import annotations
 
 import traceback
 from collections import Counter
+from functools import cached_property
 from itertools import product
 from typing import TYPE_CHECKING, Any
 from urllib.parse import urljoin
@@ -383,7 +384,7 @@ class MusicBrainzPlugin(BeetsPlugin):
                     "deezer": False,
                     "tidal": False,
                 },
-                "extra_tags": {},
+                "extra_tags": [],
             },
         )
         hostname = self.config["host"].as_str()
@@ -747,6 +748,46 @@ class MusicBrainzPlugin(BeetsPlugin):
 
         return info
 
+    @cached_property
+    def extra_mb_field_by_tag(self) -> dict[str, str]:
+        """Map configured extra tags to their MusicBrainz API field names.
+
+        Process user configuration to determine which additional MusicBrainz
+        fields should be included in search queries.
+        """
+        mb_field_by_tag = {
+            t: FIELDS_TO_MB_KEYS[t]
+            for t in self.config["extra_tags"].as_str_seq()
+            if t in FIELDS_TO_MB_KEYS
+        }
+        if mb_field_by_tag:
+            self._log.debug("Additional search terms: {}", mb_field_by_tag)
+
+        return mb_field_by_tag
+
+    def get_album_criteria(
+        self, items: list[Item], artist: str, album: str, va_likely: bool
+    ) -> dict[str, str]:
+        # Build search criteria.
+        criteria = {"release": album.lower().strip()}
+        if artist is not None:
+            criteria["artist"] = artist.lower().strip()
+        else:
+            # Various Artists search.
+            criteria["arid"] = VARIOUS_ARTISTS_ID
+        if track_count := len(items):
+            criteria["tracks"] = str(track_count)
+
+        for tag, mb_field in self.extra_mb_field_by_tag.items():
+            most_common, _ = util.plurality(i.get(tag) for i in items)
+            value = str(most_common).lower().strip()
+            if tag == "catalognum":
+                value = value.replace(" ", "")
+            if value:
+                criteria[mb_field] = value
+
+        return criteria
+
     def candidates(
         self,
         items: list[Item],
@@ -762,27 +803,7 @@ class MusicBrainzPlugin(BeetsPlugin):
         The query consists of an artist name, an album name, and,
         optionally, a number of tracks on the album and any other extra tags.
         """
-        # Build search criteria.
-        criteria = {"release": album.lower().strip()}
-        if artist is not None:
-            criteria["artist"] = artist.lower().strip()
-        else:
-            # Various Artists search.
-            criteria["arid"] = VARIOUS_ARTISTS_ID
-        if track_count := len(items):
-            criteria["tracks"] = str(track_count)
-
-        if self.config["extra_tags"]:
-            tag_list = self.config["extra_tags"].get()
-            self._log.debug("Additional search terms: {0}", tag_list)
-            for tag, value in tag_list.items():
-                if key := FIELDS_TO_MB_KEYS.get(tag):
-                    value = str(value).lower().strip()
-                    if key == "catno":
-                        value = value.replace(" ", "")
-                    if value:
-                        criteria[key] = value
-
+        criteria = self.get_album_criteria(items, artist, album, va_likely)
         # Abort if we have no search terms.
         if not any(criteria.values()):
             return

docs/changelog.rst

@@ -8,11 +8,22 @@ Unreleased
 
 New features:
 
+* :doc:`plugins/musicbrainz`: The MusicBrainz autotagger has been moved to
+  a separate plugin. The default :ref:`plugins-config` includes `musicbrainz`,
+  but if you've customized your `plugins` list in your configuration, you'll
+  need to explicitly add `musicbrainz` to continue using this functionality.
+  Configuration option `musicbrainz.enabled` has thus been deprecated.
+  :bug:`2686`
+  :bug:`4605`
 * :doc:`plugins/web`: Show notifications when a track plays. This uses the
   Media Session API to customize media notifications.
 
 Bug fixes:
 
+* :doc:`plugins/musicbrainz`: fix regression where user configured
+  ``extra_tags`` have been read incorrectly.
+  :bug:`5788`
+
 For packagers:
 
 Other changes:
@@ -39,13 +50,6 @@ been dropped.
 
 New features:
 
-* :doc:`plugins/musicbrainz`: The MusicBrainz autotagger has been moved to
-  a separate plugin. The default :ref:`plugins-config` includes `musicbrainz`,
-  but if you've customized your `plugins` list in your configuration, you'll
-  need to explicitly add `musicbrainz` to continue using this functionality.
-  Configuration option `musicbrainz.enabled` has thus been deprecated.
-  :bug:`2686`
-  :bug:`4605`
 * :doc:`plugins/lastgenre`: The new configuration option, ``keep_existing``,
   provides more fine-grained control over how pre-populated genre tags are
   handled. The ``force`` option now behaves in a more conventional manner.

test/plugins/test_musicbrainz.py

@@ -16,8 +16,11 @@
 
 from unittest import mock
 
+import pytest
+
 from beets import config
-from beets.test.helper import BeetsTestCase
+from beets.library import Item
+from beets.test.helper import BeetsTestCase, PluginMixin
 from beetsplug import musicbrainz
 
 
@@ -1063,3 +1066,42 @@ class MBLibraryTest(MusicBrainzTestCase):
             gp.side_effect = side_effect
             album = self.mb.album_for_id("d2a6f856-b553-40a0-ac54-a321e8e2da02")
             assert album.country is None
+
+
+class TestMusicBrainzPlugin(PluginMixin):
+    plugin = "musicbrainz"
+
+    @pytest.fixture
+    def mb_plugin(self, plugin_config):
+        self.config[self.plugin].set(plugin_config)
+
+        return musicbrainz.MusicBrainzPlugin()
+
+    @pytest.mark.parametrize(
+        "plugin_config,va_likely,expected_additional_criteria",
+        [
+            ({}, False, {"artist": "artist"}),
+            ({}, True, {"artist": "artist"}),
+            (
+                {"extra_tags": ["label", "catalognum"]},
+                False,
+                {"artist": "artist", "label": "abc", "catno": "abc123"},
+            ),
+        ],
+    )
+    def test_get_album_criteria(
+        self, mb_plugin, va_likely, expected_additional_criteria
+    ):
+        items = [
+            Item(catalognum="ABC 123", label="abc"),
+            Item(catalognum="ABC 123", label="abc"),
+            Item(catalognum="ABC 123", label="def"),
+        ]
+
+        assert mb_plugin.get_album_criteria(
+            items, "Artist ", " Album", va_likely
+        ) == {
+            "release": "album",
+            "tracks": str(len(items)),
+            **expected_additional_criteria,
+        }