Address MyPy issues

requirements_mypy.in

@@ -1,2 +1,3 @@
 mypy==0.812
 twisted
+hatchling  # for types

requirements_mypy.txt

@@ -12,6 +12,8 @@ automat==22.10.0
     # via twisted
 constantly==23.10.4
     # via twisted
+hatchling==1.25.0
+    # via -r requirements_mypy.in
 hyperlink==21.0.0
     # via twisted
 idna==3.7
@@ -22,8 +24,18 @@ mypy==0.812
     # via -r requirements_mypy.in
 mypy-extensions==0.4.4
     # via mypy
+packaging==24.1
+    # via hatchling
+pathspec==0.12.1
+    # via hatchling
+pluggy==1.5.0
+    # via hatchling
 six==1.16.0
     # via automat
+tomli==2.0.1
+    # via hatchling
+trove-classifiers==2024.7.2
+    # via hatchling
 twisted==24.3.0
     # via -r requirements_mypy.in
 typed-ast==1.4.3

src/incremental/_hatch.py

@@ -3,7 +3,7 @@
 
 import os
 import shlex
-from typing import TypedDict
+from typing import Any, Dict, List, Type, TypedDict
 
 from hatchling.version.source.plugin.interface import VersionSourceInterface
 from hatchling.plugin import hookimpl
@@ -18,11 +18,13 @@ class _VersionData(TypedDict):
 class IncrementalVersionSource(VersionSourceInterface):
     PLUGIN_NAME = "incremental"
 
-    def get_version_data(self) -> _VersionData:
-        config = _load_pyproject_toml(os.path.join(self.root, "./pyproject.toml"))
+    def get_version_data(self) -> _VersionData:  # type: ignore[override]
+        path = os.path.join(self.root, "./pyproject.toml")
+        config = _load_pyproject_toml(path)
+        assert config is not None, "Failed to read {}".format(path)
         return {"version": _existing_version(config.path).public()}
 
-    def set_version(self, version: str, version_data: dict):
+    def set_version(self, version: str, version_data: Dict[Any, Any]) -> None:
         raise NotImplementedError(
             f"Run `python -m incremental.version --newversion"
             f" {shlex.quote(version)}` to set the version.\n\n"
@@ -31,5 +33,5 @@ def set_version(self, version: str, version_data: dict):
 
 
 @hookimpl
-def hatch_register_version_source():
+def hatch_register_version_source() -> List[Type[VersionSourceInterface]]:
     return [IncrementalVersionSource]

src/incremental/tests/test_pyproject.py

@@ -4,7 +4,7 @@
 """Test handling of ``pyproject.toml`` configuration"""
 
 import os
-from typing import Optional
+from typing import cast, Optional, Union
 from pathlib import Path
 from twisted.trial.unittest import TestCase
 
@@ -15,7 +15,7 @@ class VerifyPyprojectDotTomlTests(TestCase):
     """Test the `_load_pyproject_toml` helper function"""
 
     def _loadToml(
-        self, toml: str, *, path: Optional[os.PathLike] = None
+        self, toml: str, *, path: Union[Path, str, None] = None
     ) -> Optional[_IncrementalConfig]:
         """
         Read a TOML snipped from a temporary file with `_load_pyproject_toml`
@@ -24,23 +24,29 @@ def _loadToml(
 
         @param path: Path to which the TOML is written
         """
-        path = path or self.mktemp()
+        path_: str
+        if path is None:
+            path_ = self.mktemp()  # type: ignore
+        else:
+            path_ = str(path)
 
-        with open(path, "w") as f:
+        with open(path_, "w") as f:
             f.write(toml)
 
         try:
-            return _load_pyproject_toml(path)
+            return _load_pyproject_toml(path_)
         except Exception as e:
             if hasattr(e, "add_note"):
-                e.add_note(f"While loading:\n\n{toml}")  # pragma: no coverage
+                e.add_note(  # type: ignore[attr-defined]
+                    f"While loading:\n\n{toml}"
+                )  # pragma: no coverage
             raise
 
     def test_fileNotFound(self):
         """
         An absent ``pyproject.toml`` file produces no result
         """
-        path = os.path.join(self.mktemp(), "pyproject.toml")
+        path = os.path.join(cast(str, self.mktemp()), "pyproject.toml")
         self.assertIsNone(_load_pyproject_toml(path))
 
     def test_nameMissing(self):