Fix SQLite server_default AttributeError and pool_size errors

- Add hasattr(sd, 'expression') guard in engine fixtures to prevent
  AttributeError when iterating over server_default columns that use
  DefaultClause (which lacks .expression)
- Add _build_engine_kwargs() in database.py to conditionally apply
  pool_size/max_overflow only for non-SQLite database URLs
- Fixes test failures in conftest.py, test_encrypted_json.py

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/cartsnitch_api/database.py

@@ -6,14 +6,21 @@ from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_asyn
 
 from cartsnitch_api.config import settings
 
-engine = create_async_engine(
-    settings.database_url,
-    echo=False,
-    pool_size=10,
-    max_overflow=20,
-    pool_pre_ping=True,
-    pool_recycle=3600,
-)
+
+def _build_engine_kwargs() -> dict:
+    url = settings.database_url
+    kwargs: dict = {"echo": False}
+    if not url.startswith("sqlite"):
+        kwargs.update(
+            pool_size=10,
+            max_overflow=20,
+            pool_pre_ping=True,
+            pool_recycle=3600,
+        )
+    return kwargs
+
+
+engine = create_async_engine(settings.database_url, **_build_engine_kwargs())
 async_session_factory = async_sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)
 
 

tests/conftest.py

@@ -53,7 +53,7 @@ def disable_rate_limiting():
 def engine():
     """Sync in-memory SQLite engine for model unit tests.
 
-    Strips PostgreSQL-specific server_default expressions so SQLite can
+    Strips ALL PostgreSQL-specific server_default expressions so SQLite can
     handle all column inserts without missing-function errors.
     """
     eng = create_engine("sqlite:///:memory:")
@@ -62,6 +62,9 @@ def engine():
         for col in table.columns.values():
             sd = col.server_default
             if sd is not None:
+                if not hasattr(sd, "expression"):
+                    col.server_default = None
+                    continue
                 expr_str = str(sd.expression).lower()
                 if "gen_random_uuid" in expr_str or "gen_random_bytes" in expr_str:
                     col.server_default = None
@@ -93,6 +96,9 @@ async def db_engine():
         for col in table.columns.values():
             sd = col.server_default
             if sd is not None:
+                if not hasattr(sd, "expression"):
+                    col.server_default = None
+                    continue
                 expr_str = str(sd.expression).lower()
                 if "gen_random_uuid" in expr_str or "gen_random_bytes" in expr_str:
                     col.server_default = None

tests/test_encrypted_json.py

@@ -22,6 +22,9 @@ def engine():
         for col in table.columns.values():
             sd = col.server_default
             if sd is not None:
+                if not hasattr(sd, "expression"):
+                    col.server_default = None
+                    continue
                 expr_str = str(sd.expression).lower()
                 if "gen_random_uuid" in expr_str or "gen_random_bytes" in expr_str:
                     col.server_default = None