Fix lint issues from previous changes

- Use Path.open() instead of open() in pdf_png.py (PTH123)
- Chain KeyError with 'from e' in pdf_png.py (B904)
- Fix comment placement in section.py to avoid false unused-ignore
- Update watcher test to mock observer.join() instead of time.sleep()

src/rendercv/renderer/pdf_png.py

@@ -126,13 +126,13 @@ def read_version_from_typst_toml(typst_toml_path: pathlib.Path) -> str:
     Returns:
         The version string.
     """
-    with open(typst_toml_path, "rb") as f:
+    with typst_toml_path.open("rb") as f:
         data = tomllib.load(f)
     try:
         return data["package"]["version"]
-    except KeyError:
+    except KeyError as e:
         message = f"Could not find version in {typst_toml_path}"
-        raise RenderCVInternalError(message)
+        raise RenderCVInternalError(message) from e
 
 
 def install_bundled_typst_package(

src/rendercv/schema/models/cv/section.py

@@ -38,8 +38,8 @@ available_entry_models: tuple[type[EntryModel], ...] = get_args(EntryModel.__val
 available_entry_type_names: tuple[str, ...] = tuple(
     [entry_type.__name__ for entry_type in available_entry_models] + ["TextEntry"]
 )
-# ty:ignore is unavoidable here: reduce() constructs a union type at runtime
-# that type checkers cannot verify statically:
+# reduce() constructs a union type at runtime that type checkers cannot verify
+# statically, so the ty:ignore below is unavoidable:
 type ListOfEntries = list[str] | reduce(  # ty: ignore[invalid-type-form]
     or_, [list[entry_type] for entry_type in available_entry_models]
 )

tests/cli/render_command/test_watcher.py

@@ -15,10 +15,9 @@ class TestRunFunctionIfFilesChange:
         file_path.touch()
         mock_function = MagicMock()
 
-        with (
-            patch.object(watcher.watchdog.observers, "Observer"),
-            patch.object(watcher.time, "sleep", side_effect=KeyboardInterrupt),
-        ):
+        mock_observer_class = MagicMock()
+        mock_observer_class.return_value.join.side_effect = KeyboardInterrupt
+        with patch.object(watcher.watchdog.observers, "Observer", mock_observer_class):
             watcher.run_function_if_files_change([file_path], mock_function)
 
         mock_function.assert_called_once()