Typecheck typeshed's code with pyright (#9793)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

tests/check_consistent.py

@@ -10,6 +10,7 @@ import re
 import sys
 import urllib.parse
 from pathlib import Path
+from typing import TypedDict
 
 import yaml
 from packaging.requirements import Requirement
@@ -93,7 +94,7 @@ def check_no_symlinks() -> None:
 
 
 def check_versions() -> None:
-    versions = set()
+    versions = set[str]()
     with open("stdlib/VERSIONS", encoding="UTF-8") as f:
         data = f.read().splitlines()
     for line in data:
@@ -115,7 +116,7 @@ def check_versions() -> None:
 
 
 def _find_stdlib_modules() -> set[str]:
-    modules = set()
+    modules = set[str]()
     for path, _, files in os.walk("stdlib"):
         for filename in files:
             base_module = ".".join(os.path.normpath(path).split(os.sep)[1:])
@@ -140,11 +141,21 @@ def get_txt_requirements() -> dict[str, SpecifierSet]:
         return {requirement.name: requirement.specifier for requirement in requirements}
 
 
+class PreCommitConfigRepos(TypedDict):
+    hooks: list[dict[str, str]]
+    repo: str
+    rev: str
+
+
+class PreCommitConfig(TypedDict):
+    repos: list[PreCommitConfigRepos]
+
+
 def get_precommit_requirements() -> dict[str, SpecifierSet]:
     with open(".pre-commit-config.yaml", encoding="UTF-8") as precommit_file:
         precommit = precommit_file.read()
-    yam = yaml.load(precommit, Loader=yaml.Loader)
-    precommit_requirements = {}
+    yam: PreCommitConfig = yaml.load(precommit, Loader=yaml.Loader)
+    precommit_requirements: dict[str, SpecifierSet] = {}
     for repo in yam["repos"]:
         if not repo.get("python_requirement", True):
             continue

tests/check_new_syntax.py

@@ -9,7 +9,7 @@ from pathlib import Path
 
 
 def check_new_syntax(tree: ast.AST, path: Path, stub: str) -> list[str]:
-    errors = []
+    errors: list[str] = []
 
     class IfFinder(ast.NodeVisitor):
         def visit_If(self, node: ast.If) -> None:
@@ -31,7 +31,7 @@ def check_new_syntax(tree: ast.AST, path: Path, stub: str) -> list[str]:
 
 
 def main() -> None:
-    errors = []
+    errors: list[str] = []
     for path in chain(Path("stdlib").rglob("*.pyi"), Path("stubs").rglob("*.pyi")):
         with open(path, encoding="UTF-8") as f:
             stub = f.read()

tests/mypy_test.py

@@ -42,7 +42,7 @@ from utils import (
 
 # Fail early if mypy isn't installed
 try:
-    import mypy  # noqa: F401
+    import mypy  # pyright: ignore[reportUnusedImport]  # noqa: F401
 except ImportError:
     print_error("Cannot import mypy. Did you install it?")
     sys.exit(1)
@@ -57,7 +57,8 @@ VersionTuple: TypeAlias = Tuple[int, int]
 Platform: TypeAlias = Annotated[str, "Must be one of the entries in SUPPORTED_PLATFORMS"]
 
 
-class CommandLineArgs(argparse.Namespace):
+@dataclass(init=False)
+class CommandLineArgs:
     verbose: int
     filter: list[Path]
     exclude: list[Path] | None
@@ -158,7 +159,7 @@ def match(path: Path, args: TestConfig) -> bool:
 
 
 def parse_versions(fname: StrPath) -> dict[str, tuple[VersionTuple, VersionTuple]]:
-    result = {}
+    result: dict[str, tuple[VersionTuple, VersionTuple]] = {}
     with open(fname, encoding="UTF-8") as f:
         for line in f:
             line = strip_comments(line)
@@ -209,7 +210,8 @@ def add_configuration(configurations: list[MypyDistConf], distribution: str) ->
     with Path("stubs", distribution, "METADATA.toml").open("rb") as f:
         data = tomli.load(f)
 
-    mypy_tests_conf = data.get("mypy-tests")
+    # TODO: This could be added to parse_metadata.py, but is currently unused
+    mypy_tests_conf: dict[str, dict[str, Any]] = data.get("mypy-tests", {})
     if not mypy_tests_conf:
         return
 
@@ -221,8 +223,8 @@ def add_configuration(configurations: list[MypyDistConf], distribution: str) ->
         assert module_name is not None, f"{section_name} should have a module_name key"
         assert isinstance(module_name, str), f"{section_name} should be a key-value pair"
 
-        values = mypy_section.get("values")
-        assert values is not None, f"{section_name} should have a values section"
+        assert "values" in mypy_section, f"{section_name} should have a values section"
+        values: dict[str, dict[str, Any]] = mypy_section["values"]
         assert isinstance(values, dict), "values should be a section"
 
         configurations.append(MypyDistConf(module_name, values.copy()))

tests/parse_metadata.py

@@ -1,3 +1,6 @@
+# This module is made specifically to abstract away those type errors
+# pyright: reportUnknownVariableType=false, reportUnknownArgumentType=false, reportUnknownMemberType=false
+
 """Tools to help parse and validate information stored in METADATA.toml files."""
 from __future__ import annotations
 
@@ -188,7 +191,8 @@ def read_metadata(distribution: str) -> StubMetadata:
     uploaded_to_pypi = data.get("upload", True)
     assert type(uploaded_to_pypi) is bool
 
-    tools_settings = data.get("tool", {})
+    empty_tools: dict[str, dict[str, object]] = {}
+    tools_settings = data.get("tool", empty_tools)
     assert isinstance(tools_settings, dict)
     assert tools_settings.keys() <= _KNOWN_METADATA_TOOL_FIELDS.keys(), f"Unrecognised tool for {distribution!r}"
     for tool, tk in _KNOWN_METADATA_TOOL_FIELDS.items():
@@ -234,7 +238,8 @@ def read_dependencies(distribution: str) -> PackageDependencies:
     If a typeshed stub is removed, this function will consider it to be an external dependency.
     """
     pypi_name_to_typeshed_name_mapping = get_pypi_name_to_typeshed_name_mapping()
-    typeshed, external = [], []
+    typeshed: list[str] = []
+    external: list[str] = []
     for dependency in read_metadata(distribution).requires:
         maybe_typeshed_dependency = Requirement(dependency).name
         if maybe_typeshed_dependency in pypi_name_to_typeshed_name_mapping:

tests/pytype_test.py

@@ -1,4 +1,6 @@
 #!/usr/bin/env python3
+# Lack of pytype typing
+# pyright: reportUnknownVariableType=false, reportUnknownMemberType=false, reportUnknownArgumentType=false, reportMissingTypeStubs=false
 """Test runner for typeshed.
 
 Depends on pytype being installed.
@@ -19,11 +21,14 @@ import traceback
 from collections.abc import Iterable, Sequence
 
 import pkg_resources
-from pytype import config as pytype_config, load_pytd  # type: ignore[import]
-from pytype.imports import typeshed  # type: ignore[import]
 
 from parse_metadata import read_dependencies
 
+assert sys.platform != "win32"
+# pytype is not py.typed https://github.com/google/pytype/issues/1325
+from pytype import config as pytype_config, load_pytd  # type: ignore[import]  # noqa: E402
+from pytype.imports import typeshed  # type: ignore[import]  # noqa: E402
+
 TYPESHED_SUBDIRS = ["stdlib", "stubs"]
 TYPESHED_HOME = "TYPESHED_HOME"
 _LOADERS = {}
@@ -155,7 +160,11 @@ def get_missing_modules(files_to_test: Sequence[str]) -> Iterable[str]:
     for distribution in stub_distributions:
         for pkg in read_dependencies(distribution).external_pkgs:
             # See https://stackoverflow.com/a/54853084
-            top_level_file = os.path.join(pkg_resources.get_distribution(pkg).egg_info, "top_level.txt")  # type: ignore[attr-defined]
+            top_level_file = os.path.join(
+                # Fixed in #9747
+                pkg_resources.get_distribution(pkg).egg_info,  # type: ignore[attr-defined]  # pyright: ignore[reportGeneralTypeIssues]
+                "top_level.txt",
+            )
             with open(top_level_file) as f:
                 missing_modules.update(f.read().splitlines())
     return missing_modules

tests/typecheck_typeshed.py

@@ -15,11 +15,12 @@ ReturnCode: TypeAlias = int
 SUPPORTED_PLATFORMS = ("linux", "darwin", "win32")
 SUPPORTED_VERSIONS = ("3.11", "3.10", "3.9")
 DIRECTORIES_TO_TEST = ("scripts", "tests")
+EMPTY: list[str] = []
 
 parser = argparse.ArgumentParser(description="Run mypy on typeshed's own code in the `scripts` and `tests` directories.")
 parser.add_argument(
     "dir",
-    choices=DIRECTORIES_TO_TEST + ([],),
+    choices=DIRECTORIES_TO_TEST + (EMPTY,),
     nargs="*",
     action="extend",
     help=f"Test only these top-level typeshed directories (defaults to {DIRECTORIES_TO_TEST!r})",

tests/utils.py

@@ -135,4 +135,6 @@ def spec_matches_path(spec: pathspec.PathSpec, path: Path) -> bool:
     normalized_path = path.as_posix()
     if path.is_dir():
         normalized_path += "/"
-    return spec.match_file(normalized_path)
+    # pathspec.PathSpec.match_file has partially Unknown file parameter
+    # https://github.com/cpburnz/python-pathspec/pull/75
+    return spec.match_file(normalized_path)  # pyright: ignore[reportUnknownMemberType]