Improve UUID validation and add comprehensive tests

Co-authored-by: snejus <16212750+snejus@users.noreply.github.com>

beetsplug/_utils/musicbrainz.py

@@ -197,9 +197,21 @@ class MusicBrainzAPI(RequestHandler):
         * Values are lowercased and stripped of whitespace.
         """
         def format_value(value: str) -> str:
-            """Format a filter value, quoting it unless it's a UUID."""
-            # Check if value is a UUID (MBID) - 8-4-4-4-12 format with hyphens
-            if len(value) == 36 and value.count("-") == 4:
+            """Format a filter value, quoting it unless it's a UUID.
+            
+            UUIDs are detected by checking for the 8-4-4-4-12 format:
+            - Total length of 36 characters
+            - Exactly 4 hyphens
+            - Hyphens at positions 8, 13, 18, and 23
+            """
+            if (
+                len(value) == 36
+                and value.count("-") == 4
+                and value[8] == "-"
+                and value[13] == "-"
+                and value[18] == "-"
+                and value[23] == "-"
+            ):
                 # Likely a UUID/MBID, don't quote it
                 return value
             # Regular string value, quote it

test/plugins/utils/test_musicbrainz.py

@@ -1,5 +1,7 @@
 from beetsplug._utils.musicbrainz import MusicBrainzAPI
 
+import pytest
+
 
 def test_group_relations():
     raw_release = {
@@ -80,3 +82,90 @@ def test_group_relations():
             },
         ],
     }
+
+
+class TestSearchQueryConstruction:
+    """Test query construction in the search method."""
+
+    @pytest.fixture
+    def api(self):
+        return MusicBrainzAPI()
+
+    @pytest.fixture
+    def mock_get_json(self, monkeypatch):
+        """Mock get_json to capture queries without making actual API calls."""
+        queries = []
+        
+        def capture_query(*args, **kwargs):
+            if 'params' in kwargs and 'query' in kwargs['params']:
+                queries.append(kwargs['params']['query'])
+            return {"releases": []}
+        
+        monkeypatch.setattr(
+            "beetsplug._utils.musicbrainz.MusicBrainzAPI.get_json",
+            capture_query
+        )
+        return queries
+
+    def test_uuid_not_quoted(self, api, mock_get_json):
+        """Test that valid UUIDs are not quoted in search queries."""
+        uuid = "89ad4ac3-39f7-470e-963a-56509c546377"
+        api.search("release", {"arid": uuid})
+        
+        assert len(mock_get_json) == 1
+        query = mock_get_json[0]
+        assert f"arid:{uuid}" in query
+        assert f'arid:"{uuid}"' not in query
+
+    def test_string_quoted(self, api, mock_get_json):
+        """Test that regular strings are quoted in search queries."""
+        api.search("release", {"artist": "Test Artist"})
+        
+        assert len(mock_get_json) == 1
+        query = mock_get_json[0]
+        assert 'artist:"test artist"' in query
+
+    def test_mixed_uuid_and_string(self, api, mock_get_json):
+        """Test that UUIDs and strings are formatted correctly together."""
+        uuid = "89ad4ac3-39f7-470e-963a-56509c546377"
+        api.search("release", {
+            "release": "Test Album",
+            "arid": uuid
+        })
+        
+        assert len(mock_get_json) == 1
+        query = mock_get_json[0]
+        assert 'release:"test album"' in query
+        assert f"arid:{uuid}" in query
+        assert f'arid:"{uuid}"' not in query
+
+    def test_invalid_uuid_quoted(self, api, mock_get_json):
+        """Test that invalid UUID-like strings are quoted."""
+        # Wrong length
+        api.search("release", {"test": "not-a-uuid-123"})
+        assert 'test:"not-a-uuid-123"' in mock_get_json[0]
+        
+        mock_get_json.clear()
+        
+        # Wrong hyphen positions
+        api.search("release", {"test": "abcd-efgh-ijkl-mnop-qrstuvwxyz123456"})
+        assert 'test:"abcd-efgh-ijkl-mnop-qrstuvwxyz123456"' in mock_get_json[0]
+        
+        mock_get_json.clear()
+        
+        # Correct length and hyphen count but wrong positions
+        api.search("release", {"test": "12345678-123-456-7890-123456789012"})
+        assert 'test:"12345678-123-456-7890-123456789012"' in mock_get_json[0]
+
+    def test_empty_value_filtered(self, api, mock_get_json):
+        """Test that empty values are filtered out of the query."""
+        api.search("release", {
+            "release": "Test Album",
+            "empty": ""
+        })
+        
+        assert len(mock_get_json) == 1
+        query = mock_get_json[0]
+        assert 'release:"test album"' in query
+        assert "empty" not in query
+