Add type checking with ty

Author: flashcode

Makefile

@@ -23,10 +23,13 @@ all: check
 
 check: lint test
 
-lint: ruff
+lint: ruff ty
 
 ruff:
 	uvx ruff check
 
+ty:
+	uvx ty check
+
 test:
 	uv run pytest -vv --cov=msgcheck --cov-report=term-missing

src/msgcheck/po.py

@@ -134,7 +134,7 @@ def __init__(  # noqa: PLR0913
         self.filename = filename
         self.line = line
         # unescape strings
-        msg = {k: escape_decode(v)[0].decode(charset) for k, v in msg.items()}
+        msg = {k: escape_decode(v)[0].decode(charset) for k, v in msg.items()}  # ty: ignore[unresolved-attribute]
         # build messages as a list of tuples: (string, translation)
         self.messages = []
         if "msgid_plural" in msg:
@@ -544,7 +544,7 @@ def _get_language_checker(self, po_file: PoFile, reports: list[PoReport]) -> lis
                         tmp_file.flush()
                         _dict = DictWithPWL(lang, tmp_file.name)
                 else:
-                    _dict = DictWithPWL(lang, None)
+                    _dict = DictWithPWL(lang, None)  # ty: ignore[invalid-argument-type]
                 checker.append(SpellChecker(_dict))
             except DictNotFoundError:
                 reports.append(