Ensure template works with pright in strict mode (#184)

Author: callumforrester

docs/how-to/strict-mode.md

@@ -0,0 +1,17 @@
+# Enable Pyright's Strict Mode
+
+For projects using pyright you can enable strict mode for stricter than normal type checking. See [the docs](https://github.com/microsoft/pyright/blob/main/docs/configuration.md) for a full breakdown. The primary benefits are increased confidence in code that has been more thoroughly analyzed and a shorter development time thanks to fast feedback from the type checker.
+
+## Configuration
+
+Add the `strict` line to `pyproject.toml` as follows:
+
+```toml
+[tool.pyright]
+strict = ["src", "tests"]
+reportMissingImports = false # Ignore missing stubs in imported modules
+```
+
+## Third Party Libraries
+
+Strict mode does not usually work well with libraries that do not have [type stubs](https://github.com/microsoft/pyright/blob/main/docs/type-stubs.md), you will likely need a `# type: ignore` on any line that directly uses the library code. This may limit the usefulness of pyright but it can still be worth doing to ensure your own code is internally consistent.

template/src/{{ package_name }}/__main__.py.jinja

@@ -1,14 +1,20 @@
 from argparse import ArgumentParser
+from collections.abc import Sequence
 
 from . import __version__
 
 __all__ = ["main"]
 
 
-def main(args=None):
+def main(args: Sequence[str] | None = None) -> None:
     parser = ArgumentParser()
-    parser.add_argument("-v", "--version", action="version", version=__version__)
-    args = parser.parse_args(args)
+    parser.add_argument(
+        "-v",
+        "--version",
+        action="version",
+        version=__version__,
+    )
+    parser.parse_args(args)
 
 
 # test with: python -m {{package_name}}

tests/conftest.py

@@ -1,4 +1,5 @@
 import os
+from typing import Any
 
 import pytest
 
@@ -7,9 +8,14 @@
 if os.getenv("PYTEST_RAISE", "0") == "1":
 
     @pytest.hookimpl(tryfirst=True)
-    def pytest_exception_interact(call):
-        raise call.excinfo.value
+    def pytest_exception_interact(call: pytest.CallInfo[Any]):
+        if call.excinfo is not None:
+            raise call.excinfo.value
+        else:
+            raise RuntimeError(
+                f"{call} has no exception data, an unknown error has occurred"
+            )
 
     @pytest.hookimpl(tryfirst=True)
-    def pytest_internalerror(excinfo):
+    def pytest_internalerror(excinfo: pytest.ExceptionInfo[Any]):
         raise excinfo.value

tests/test_example.py

@@ -149,3 +149,17 @@ def __init__(self):
         stream.write(code)
     with pytest.raises(AssertionError, match="SLF001 Private member accessed: `_bar`"):
         run("ruff check")
+
+
+def test_works_in_pyright_strict_mode(tmp_path: Path):
+    copy_project(tmp_path)
+    pyproject_toml = tmp_path / "pyproject.toml"
+
+    # Enable strict mode
+    run_pipe(
+        f'sed -i \'/\\[tool.pyright\\]/a\\strict = ["src", "tests"]\' {pyproject_toml}'
+    )
+
+    # Ensure pyright is still happy
+    run = make_venv(tmp_path)
+    run(f"./venv/bin/pyright {tmp_path}")