improve type hints

This makes static analyzers happy.

Author: dlech

pyproject.toml

@@ -9,7 +9,7 @@ description = "Python wrapper for the mpy-cross tool from MicroPython."
 readme = "README.md"
 
 [project.scripts]
-"mpy-cross-v6.3" = "mpy_cross_v6_3:_run"
+"mpy-cross-v6.3" = "mpy_cross_v6_3:run"
 
 [tool.setuptools.packages.find]
 where = ["src"]

src/mpy_cross_v6_3/__init__.py

@@ -7,7 +7,7 @@
 from typing import List, Optional, Tuple
 
 
-MPY_CROSS_PATH = (
+MPY_CROSS_PATH = str(
     (pathlib.Path(__file__).parent / "mpy-cross")
     .with_suffix(".exe" if platform.system() == "Windows" else "")
     .absolute()
@@ -42,7 +42,7 @@ def mpy_cross_compile(
     emit: Optional[Emitter] = None,
     heap_size: Optional[int] = None,
     extra_args: Optional[List[str]] = None,
-) -> Tuple[subprocess.CompletedProcess, Optional[bytes]]:
+) -> Tuple[subprocess.CompletedProcess[bytes], Optional[bytes]]:
     """
     Compiles a file using mpy-cross.
 
@@ -75,13 +75,13 @@ def mpy_cross_compile(
         ...
 
     """
-    with tempfile.TemporaryDirectory() as tmp_dir:
-        tmp_dir = pathlib.Path(tmp_dir)
+    with tempfile.TemporaryDirectory() as tmp_dir_name:
+        tmp_dir = pathlib.Path(tmp_dir_name)
 
         with open(tmp_dir / "tmp.py", "w") as in_file:
             in_file.write(file_contents)
 
-        args = [MPY_CROSS_PATH, in_file.name, "-s", file_name]
+        args: list[str] = [MPY_CROSS_PATH, in_file.name, "-s", file_name]
 
         if optimization_level is not None:
             if optimization_level not in range(4):
@@ -124,7 +124,7 @@ def mpy_cross_version() -> str:
     return proc.stdout.decode().strip()
 
 
-def _run():
+def run() -> None:
     """
     Run mpy-cross directly.
     """

src/mpy_cross_v6_3/__main__.py

@@ -1,4 +1,4 @@
-from . import _run
+from . import run
 
 if __name__ == "__main__":
-    _run()
+    run()

tests/test_mpy_cross.py

@@ -6,6 +6,7 @@
 def test_compile_no_opts():
     p, mpy = mpy_cross_compile("test.py", "")
     p.check_returncode()
+    assert mpy is not None
 
     magic, version, flags, small_int_bits = struct.unpack_from("BBBB", mpy)
 
@@ -18,6 +19,7 @@ def test_compile_no_opts():
 def test_compile_opt_small_int_bits():
     p, mpy = mpy_cross_compile("test.py", "", small_number_bits=63)
     p.check_returncode()
+    assert mpy is not None
 
     magic, version, flags, small_int_bits = struct.unpack_from("BBBB", mpy)