ci: run statement tests against sqlite and postgresql drivers - #9

Motivation

CI currently only runs the framework's own unit tests (uv run pytest -vs tests/ in .github/workflows/test.yaml) — no ADBC driver is ever exercised. Changes to the validation suite get zero real-driver execution before merging; driver repositories only run the suite at their pinned revision, so breakage is discovered late.

What this adds

A minimal, CI-only smoke harness under smoke/ (not shipped as part of the package) plus a new Driver Smoke Test workflow that runs the driver-facing statement tests (adbc_drivers_validation/tests/statement.py) against two real drivers:

• sqlite job: the released adbc-driver-sqlite PyPI wheel against a local SQLite database file.
• postgresql job: the released adbc-driver-postgresql PyPI wheel against a postgres:18 service container.

The harness (smoke/tests/) defines minimal SQLiteQuirks/PostgreSQLQuirks (only what the statement tests need), re-exports the shared fixtures from adbc_drivers_validation.tests.conftest, and selects the driver via the SMOKE_DRIVER environment variable so one harness serves both jobs. Statement tests only for now — query/ingest/connection tests need per-vendor query corpora and fuller quirks, and can be layered on later.

Supporting tweaks:

• pyproject.toml: scope setuptools package discovery to adbc_drivers_validation* (the new top-level smoke/ directory otherwise breaks flat-layout auto-discovery).
• pytest.ini: set testpaths = tests so a bare pytest run keeps collecting only the framework unit tests; the smoke tests use their own smoke/pytest.ini.
• .rat-excludes: exclude the empty smoke/queries/.gitkeep placeholder.

Local verification

• SQLite job command: 6 passed, 1 skipped (test_execute_schema_noalias — the released wheel raises NOT_IMPLEMENTED for execute_schema).
• PostgreSQL job command against a local postgres:18 container: all 7 statement tests passed (test_parameter_execute, test_parameter_schema, test_prepare, test_execute_schema_noalias, test_rows_affected, test_transaction_toggle, test_nonascii_queries).
• uv run pytest -vs tests/: 211 passed, 1 skipped.
• uv run ty check: clean.
• pre-commit run --all-files: all hooks pass (including Apache RAT license check).
• uvx zizmor .github/workflows/driver-smoke.yaml: no findings.

🤖 Generated with Claude Code

https://claude.ai/code/session_01VsDgjiYuJYrp59oto64m9D