[CHORE] Add ruff annotation checks to check-typing recipe

[oberstet]

Summary

Enhance the just check-typing recipe to include ruff check --select ANN,UP alongside the existing ty check, making it easier for contributors to validate type annotations locally before pushing.

This was suggested by @bblommers in PR #1838 and aligns with the typed subset initiative in #1839.

Current State

justfile check-typing recipe

Currently only runs ty check with many --ignore flags:

ty check \
    --python "${VENV_PATH}/bin/python" \
    --ignore unresolved-import \
    --ignore unresolved-attribute \
    --ignore unresolved-reference \
    --ignore possibly-missing-attribute \
    --ignore call-non-callable \
    --ignore invalid-assignment \
    --ignore invalid-argument-type \
    --ignore invalid-method-override \
    --ignore invalid-type-form \
    --ignore unsupported-operator \
    --ignore too-many-positional-arguments \
    --ignore unknown-argument \
    --ignore not-subscriptable \
    --ignore not-iterable \
    --ignore no-matching-overload \
    --ignore conflicting-declarations \
    src/autobahn/

Missing: ruff check --select ANN,UP for annotation presence and modern syntax.

CI workflow (main.yml)

The quality-checks job runs:

• just check-format cpy314 — ruff formatting/linting
• just check-typing cpy314 — ty type checking

Once we update the check-typing recipe, CI will automatically pick up the changes.

Proposed Changes

1. Add ruff annotation checks to check-typing

# Add before ty check:
echo "==> Checking type annotation presence and style (via ruff)..."
ruff check --select ANN,UP,TCH src/autobahn/

echo "==> Running static type checks (via ty)..."
ty check ...

Rule sets:

Rule	Purpose
ANN	flake8-annotations — missing type annotations
UP	pyupgrade — modernize syntax (Optional → X | None, etc.)
TCH	flake8-type-checking — proper TYPE_CHECKING imports

2. Configure ruff in pyproject.toml

Add/update ruff configuration to match the style guide from #1839:

[tool.ruff]
target-version = "py311"
line-length = 120

[tool.ruff.lint]
select = [
    "ANN",  # flake8-annotations
    "I",    # isort
    "E",    # pycodestyle errors
    "F",    # pyflakes
    "W",    # pycodestyle warnings
    "UP",   # pyupgrade
    "TCH",  # flake8-type-checking
]

[tool.ruff.lint.flake8-annotations]
mypy-init-return = true
suppress-none-returning = false
allow-star-arg-any = false

[tool.ruff.lint.isort]
required-imports = ["from __future__ import annotations"]

3. Gradual ignore removal

The current ty check has many --ignore flags with a FIXME comment. As typing coverage improves per #1839, these should be progressively removed:

Phase 1 (now): Add ruff ANN,UP,TCH checks (may need --ignore initially)
Phase 2 (ongoing): As modules get typed, remove corresponding --ignore flags
Phase 3 (goal): Zero ignores — full strict mode

4. Verify CI integration

After updating check-typing, verify that:

• just check-typing cpy314 passes locally
• CI quality-checks job runs the updated recipe
• Any new ruff errors are either fixed or explicitly ignored with inline comments

Implementation Notes

Option A: Strict from the start

• Run ruff check --select ANN,UP,TCH without ignores
• Fix all violations before merging
• Cleaner but more work upfront

Option B: Gradual adoption

• Add ruff checks with --ignore for specific rules initially
• Remove ignores as files are typed
• Matches the "piece by piece" approach

Recommend Option B to avoid blocking on full codebase typing.

Acceptance Criteria

• just check-typing runs both ruff check --select ANN,UP,TCH and ty check
• pyproject.toml has ruff configuration matching style guide
• CI quality-checks job passes with updated recipe
• Documentation updated (if any contributor docs exist)

Related

• [FEATURE] Constrain codebase to statically typed and region-based lifetimes Python subset #1839 — Constrain codebase to statically typed Python subset (parent issue)
• Autobahn WebSocket Protocol - Improve typing #1838 — Initial typing contribution by @bblommers (merged)
• [FEATURE] Constraint code base to statically typed Python subset txaio#214 — Same initiative for txaio

References

• ruff ANN rules
• ruff UP rules
• ruff TCH rules

Checklist

• I have searched existing issues to avoid duplicates
• I have described the problem clearly
• I have provided use cases
• I have considered alternatives
• I have assessed impact and breaking changes