Fix strict type errors

.github/workflows/python-test.yml

@@ -29,6 +29,6 @@ jobs:
           # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
           flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
       - name: Type checking with mypy
-        run: mypy --ignore-missing-imports --strict .
+        run: mypy --ignore-missing-imports --strict beetsplug
       - name: Test with unittest
         run: python -m unittest discover -s tests

beetsplug/date_wrapper.py

@@ -1,5 +1,5 @@
 import datetime
-from typing import Optional
+from typing import Optional, TypeVar
 
 from dateutil import parser
 
@@ -12,7 +12,7 @@ class DateWrapper(datetime.datetime):
     """
 
     def __new__(cls, y: Optional[int] = None, m: Optional[int] = None, d: Optional[int] = None,
-                iso_string: Optional[str] = None):
+                iso_string: Optional[str] = None) -> DateWrapper:
         """
         Create a new datetime object using a convenience wrapper.
         Must specify at least one of either year or iso_string.
@@ -37,12 +37,12 @@ def __new__(cls, y: Optional[int] = None, m: Optional[int] = None, d: Optional[i
         return datetime.datetime.__new__(cls, year, month, day)
 
     @classmethod
-    def today(cls):
+    def today(cls) -> DateWrapper:
         today = datetime.date.today()
         return DateWrapper(today.year, today.month, today.day)
 
     def __init__(self, y: Optional[int] = None, m: Optional[int] = None, d: Optional[int] = None,
-                 iso_string: Optional[str] = None):
+                 iso_string: Optional[str] = None) -> None:
         if y is not None:
             self.y = min(max(y, datetime.MINYEAR), datetime.MAXYEAR)
             self.m = m if (m is None or 0 < m <= 12) else 1
@@ -74,7 +74,10 @@ def __init__(self, y: Optional[int] = None, m: Optional[int] = None, d: Optional
         else:
             raise TypeError("Must specify a value for year or a date string")
 
-    def __lt__(self, other):
+    def __lt__(self, other: datetime.date) -> bool:
+        if not isinstance(other, DateWrapper):
+            return NotImplemented
+
         if self.y != other.y:
             return self.y < other.y
         elif self.m is None:
@@ -93,7 +96,10 @@ def __lt__(self, other):
             else:
                 return self.m < other.m
 
-    def __eq__(self, other):
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, DateWrapper):
+            return NotImplemented
+
         if self.y != other.y:
             return False
         elif self.m is not None and other.m is not None:

beetsplug/oldestdate.py

@@ -17,6 +17,7 @@
 
 # Type alias
 Recording = dict[str, Any]
+Work = dict[str, Any]
 
 
 def _get_work_id_from_recording(recording: Recording) -> Optional[str]:
@@ -70,16 +71,17 @@ def _is_cover(recording: Recording) -> bool:
     return False
 
 
-def _fetch_work(work_id: str) -> Recording:
+def _fetch_work(work_id: str) -> dict[str, Any]:
     """Fetch work, including recording relations"""
-    return musicbrainzngs.get_work_by_id(work_id, ['recording-rels'])['work']
+    work: Work = musicbrainzngs.get_work_by_id(work_id, ['recording-rels'])['work']
+    return work
 
 
-class OldestDatePlugin(BeetsPlugin):
+class OldestDatePlugin(BeetsPlugin): # type: ignore
     _importing: bool = False
     _recordings_cache: dict[str, Recording] = dict()
 
-    def __init__(self):
+    def __init__(self) -> None:
         super(OldestDatePlugin, self).__init__()
         self.import_stages = [self._on_import]
         self.config.add({
@@ -122,7 +124,7 @@ def __init__(self):
                 mediafile.StorageStyle(recording_field))
             self.add_media_field(recording_field, field)
 
-    def commands(self):
+    def commands(self) -> list[ui.Subcommand]:
         recording_date_command = ui.Subcommand(
             'oldestdate',
             help="Retrieve the date of the oldest known recording or release of a track.",
@@ -240,7 +242,7 @@ def _process_file(self, item: Item) -> None:
 
     def _fetch_recording(self, recording_id: str) -> Recording:
         """Fetch and cache recording from MusicBrainz, including releases and work relations"""
-        recording = musicbrainzngs.get_recording_by_id(recording_id, ['artists', 'releases', 'work-rels'])['recording']
+        recording: Recording = musicbrainzngs.get_recording_by_id(recording_id, ['artists', 'releases', 'work-rels'])['recording']
         self._recordings_cache[recording_id] = recording
         return recording