[iloveitaly]

Motivation

Pyright was the Python type checker in lint, config, and the editor. Pyrefly is the replacement.

Description

• Swap the pyright[nodejs] dev dependency for pyrefly 1.4.0.
• Replace [tool.pyright] with [tool.pyrefly]. infer-with-first-use = false keeps empty containers as Any, matching pyright standard mode. Project excludes stay on local clones, generated migrations, playground, and tmp. Pyrefly already excludes node_modules, caches, and virtualenvs.
• just py_lint runs pyrefly check. The default . passes no paths so project-excludes apply. CI uses --output-format=full-text-with-github and rewrites absolute paths to repo-relative annotation paths.
• Editor: recommend meta.pyrefly, set python.languageServer to None, and disable Cursor's Pyright language services.
• Drop PYRIGHT_PYTHON_PYLANCE_VERSION.
• Fixes required for a clean check: production breakpoints use a no-op hook (None made breakpoint() raise TypeError), location fixtures are a TypedDict, and invalid quarters go through model_validate. posthog.default_client and TypeIDType.raw() keep a pyrefly ignore because the stubs do not describe the runtime types.

Screenshots / Test

• just py_lint exits 0. Pyrefly reports 0 errors.
• CI=1 just py_lint exits 0, including the GitHub annotation format.
• just py_lint app/utils/address.py app/routes/utils/pydantic_lists.py exits 0 after the old pyright ignores were removed.
• Invalid quarter numbers 0 and 5 still raise ValidationError.
• pytest tests/unit/dates_test.py did not collect here: app startup could not resolve redis.workspace.orb.local.

Three warnings do not fail the command: deprecated client.charges, unreachable code after the early return in migrations/sanitize_production.py, and missing stubs for psutil.

Links

• https://pyrefly.org/en/docs/migrating-from-pyright/