(clean) strict project.toml, cleaned pylint issues and refactored and clean code

Author: stefankumarasinghe

.gitignore

@@ -9,4 +9,5 @@ __pycache__/
 .ruff_cache
 .coverage
 .vscode/
-.hypothesis/
+.hypothesis/
+.venv/

.pre-commit-config.yaml

@@ -4,7 +4,14 @@ repos:
       - id: resolver-unit-tests
         name: Resolver unit tests
         language: system
-        entry: bash -lc 'python -m pytest -q'
+        entry: >-
+          bash -lc 'R="$(git rev-parse --show-toplevel 2>/dev/null || echo "$PWD")";
+          cd "$R" || exit 1;
+          P=""; for c in "$PWD/.venv/bin/python" "$PWD/venv/bin/python" "$(command -v python3)" "$(command -v python)"; do
+          [[ -n "$c" && -x "$c" ]] || continue;
+          "$c" -c "import pytest" 2>/dev/null && { P="$c"; break; }; done;
+          [[ -n "$P" ]] || { echo "error: no Python with pytest; use .venv and pip install -e .[dev]" >&2; exit 1; };
+          "$P" -m pytest -q'
         pass_filenames: false
         files: \.py$
         exclude: (^|/)tests/
@@ -14,13 +21,14 @@ repos:
         name: Resolver mypy
         language: system
         entry: >-
-          bash -lc 'APP_ENV=development
-          ENVIRONMENT=development
-          RESOLVER_DATABASE_URL=postgresql://ci_user:ci_password_123@localhost:5432/resolver
-          RESOLVER_EXPECTED_SERVICE_TOKEN=ci_resolver_expected_service_token_123456789
-          RESOLVER_CONTEXT_VERIFY_KEY=ci_resolver_context_verify_key_12345678901234567890
-          PYTHONPATH=$PWD
-          mypy --config-file "$PWD/pyproject.toml" "$@"' --
+          bash -lc 'R="$(git rev-parse --show-toplevel 2>/dev/null || echo "$PWD")";
+          cd "$R" || exit 1;
+          P=""; for c in "$PWD/.venv/bin/python" "$PWD/venv/bin/python" "$(command -v python3)" "$(command -v python)"; do
+          [[ -n "$c" && -x "$c" ]] || continue;
+          "$c" -c "import mypy, numpy, sqlalchemy, pydantic, httpx" 2>/dev/null && { P="$c"; break; }; done;
+          [[ -n "$P" ]] || { echo "error: no Python with mypy + resolver deps; pip install -e .[dev] in resolver/" >&2; exit 1; };
+          APP_ENV=development ENVIRONMENT=development RESOLVER_DATABASE_URL=postgresql://ci_user:ci_password_123@localhost:5432/resolver RESOLVER_EXPECTED_SERVICE_TOKEN=ci_resolver_expected_service_token_123456789 RESOLVER_CONTEXT_VERIFY_KEY=ci_resolver_context_verify_key_12345678901234567890 PYTHONPATH="$PWD" "$P" -m mypy --python-executable "$P" --cache-dir /tmp/resolver-mypy-cache --config-file "$PWD/pyproject.toml" .'
+        pass_filenames: false
         files: \.py$
         exclude: (^|/)tests/
         types: [python]
@@ -29,13 +37,14 @@ repos:
         name: Resolver pylint
         language: system
         entry: >-
-          bash -lc 'APP_ENV=development
-          ENVIRONMENT=development
-          RESOLVER_DATABASE_URL=postgresql://ci_user:ci_password_123@localhost:5432/resolver
-          RESOLVER_EXPECTED_SERVICE_TOKEN=ci_resolver_expected_service_token_123456789
-          RESOLVER_CONTEXT_VERIFY_KEY=ci_resolver_context_verify_key_12345678901234567890
-          PYTHONPATH=$PWD
-          pylint --rcfile "$PWD/pyproject.toml" "$@"' --
+          bash -lc 'R="$(git rev-parse --show-toplevel 2>/dev/null || echo "$PWD")";
+          cd "$R" || exit 1;
+          P=""; for c in "$PWD/.venv/bin/python" "$PWD/venv/bin/python" "$(command -v python3)" "$(command -v python)"; do
+          [[ -n "$c" && -x "$c" ]] || continue;
+          "$c" -c "import pylint, numpy, sqlalchemy, pydantic, httpx" 2>/dev/null && { P="$c"; break; }; done;
+          [[ -n "$P" ]] || { echo "error: no Python with pylint + resolver deps; pip install -e .[dev] in resolver/" >&2; exit 1; };
+          APP_ENV=development ENVIRONMENT=development RESOLVER_DATABASE_URL=postgresql://ci_user:ci_password_123@localhost:5432/resolver RESOLVER_EXPECTED_SERVICE_TOKEN=ci_resolver_expected_service_token_123456789 RESOLVER_CONTEXT_VERIFY_KEY=ci_resolver_context_verify_key_12345678901234567890 PYTHONPATH="$PWD" "$P" -m pylint --rcfile "$PWD/pyproject.toml" .'
+        pass_filenames: false
         files: \.py$
         exclude: (^|/)tests/
         types: [python]

database.py

@@ -14,7 +14,7 @@
 import re
 import logging
 from contextlib import contextmanager
-from typing import Callable, Iterator, Optional
+from typing import Iterator, Optional, Protocol
 
 from sqlalchemy import create_engine, text
 from sqlalchemy.exc import SQLAlchemyError
@@ -25,8 +25,18 @@
 from db_models import Base
 
 logger = logging.getLogger(__name__)
+
+
+class _SessionFactory(Protocol):
+    def __call__(self) -> Session: ...
+
+
+def _new_session(factory: _SessionFactory) -> Session:
+    return factory()
+
+
 _ENGINE: Optional[Engine] = None
-_SESSION_FACTORY: Optional[Callable[[], Session]] = None
+_SESSION_FACTORY: Optional[_SessionFactory] = None
 
 
 def _ensure_postgres_database_exists(database_url: str) -> None:
@@ -68,19 +78,23 @@ def init_database(database_url: str) -> None:
         pool_timeout=int(os.getenv("RESOLVER_DB_POOL_TIMEOUT", "30")),
         pool_recycle=int(os.getenv("RESOLVER_DB_POOL_RECYCLE", "1800")),
     )
-    session_factory = sessionmaker(bind=engine, autoflush=False, expire_on_commit=False)
+    factory = sessionmaker(bind=engine, autoflush=False, expire_on_commit=False)
     globals()["_ENGINE"] = engine
-    globals()["_SESSION_FACTORY"] = session_factory
+    globals()["_SESSION_FACTORY"] = factory
+
+
+def _require_session_factory() -> _SessionFactory:
+    factory = _SESSION_FACTORY
+    if factory is None or not callable(factory):
+        raise RuntimeError("Database not initialized")
+    return factory
 
 
 @contextmanager
 def get_db_session() -> Iterator[Session]:
-    if _ENGINE is None or _SESSION_FACTORY is None:
-        raise RuntimeError("Database not initialized")
-    session_factory = _SESSION_FACTORY
-    if not callable(session_factory):
+    if _ENGINE is None:
         raise RuntimeError("Database not initialized")
-    session = session_factory()
+    session = _new_session(_require_session_factory())
     try:
         yield session
         session.commit()