Use Ruff for from __future__ import annotations checks (#10910)

.github/workflows/tests.yml

@@ -45,6 +45,15 @@ jobs:
           python-version: "3.11"
       - run: ./tests/check_new_syntax.py
 
+  ruff:
+    name: Lint with Ruff
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: chartboost/ruff-action@v1
+        with:
+          version: "0.1.0" # must match .pre-commit-config.yaml and requirements-test.txt
+
   flake8:
     name: Lint with Flake8
     runs-on: ubuntu-latest

.pre-commit-config.yaml

@@ -20,10 +20,10 @@ repos:
       - id: isort
         name: isort (python)
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.1.0 # must match requirements-tests.txt
+    rev: v0.1.0 # must match requirements-tests.txt and tests.yml
     hooks:
       - id: ruff
-        args: [--exit-non-zero-on-fix]
+        args: [--exit-non-zero-on-fix, --fix-only]
   - repo: https://github.com/pycqa/flake8
     rev: 6.1.0 # must match requirements-tests.txt
     hooks:

pyproject.toml

@@ -60,15 +60,17 @@ known_first_party = ["parse_metadata", "utils"]
 
 [tool.ruff]
 line-length = 130
+# Oldest supported Python version
 target-version = "py37"
 fix = true
 exclude = [
-    # We're only interested in autofixes for our stubs
-    "*.py",
     # Ignore generated protobuf stubs
     "*_pb2.pyi",
-    # virtual environment, cache directories, etc.:
+    # virtual environment
     ".env",
+    ".venv",
+    "env",
+    # cache directories, etc.:
     ".git",
     ".mypy_cache",
     ".pytype",
@@ -80,6 +82,7 @@ exclude = [
 # only enable rules that are relevant to stubs
 select = [
     "F401", # Remove unused imports
+    "FA", # flake8-future-annotations
     "PYI009", # use `...`, not `pass`, in empty class bodies
     "PYI010", # function bodies must be empty
     "PYI012", # class bodies must not contain `pass`

requirements-tests.txt

@@ -10,7 +10,7 @@ isort==5.12.0            # must match .pre-commit-config.yaml
 mypy==1.6.1
 pre-commit-hooks==4.5.0  # must match .pre-commit-config.yaml
 pytype==2023.10.17; platform_system != "Windows" and python_version < "3.12"
-ruff==0.1.0              # must match .pre-commit-config.yaml
+ruff==0.1.0              # must match .pre-commit-config.yaml and tests.yml
 
 # Libraries used by our various scripts.
 aiohttp==3.8.5; python_version < "3.12"  # aiohttp can't be installed on 3.12 yet

tests/check_consistent.py

@@ -83,9 +83,6 @@ def check_test_cases() -> None:
         bad_test_case_filename = 'Files in a `test_cases` directory must have names starting with "check_"; got "{}"'
         for file in testcase_dir.rglob("*.py"):
             assert file.stem.startswith("check_"), bad_test_case_filename.format(file)
-            with open(file, encoding="UTF-8") as f:
-                lines = {line.strip() for line in f}
-            assert "from __future__ import annotations" in lines, "Test-case files should use modern typing syntax where possible"
 
 
 def check_no_symlinks() -> None: