Add tests for idempotency in migraionts

libs/checkpoint-postgres/tests/test_async_store.py

@@ -69,6 +69,10 @@ async def store(request) -> AsyncIterator[AsyncPostgresStore]:
                 for mig in store.MIGRATIONS
             ]
             await store.setup()
+            async with store._cursor() as cur:
+                # drop the migration index
+                await cur.execute("DROP TABLE IF EXISTS store_migrations")
+            await store.setup()  # Will fail if migrations aren't idempotent
 
         if request.param == "pipe":
             async with AsyncPostgresStore.from_conn_string(

libs/checkpoint-postgres/tests/test_store.py

@@ -415,6 +415,10 @@ def _create_vector_store(
             ttl={"default_ttl": 2, "refresh_on_read": True} if enable_ttl else None,
         ) as store:
             store.setup()
+            with store._cursor() as cur:
+                # drop the migration index
+                cur.execute("DROP TABLE IF EXISTS store_migrations")
+            store.setup()  # Will fail if migrations aren't idempotent
             yield store
     finally:
         with Connection.connect(admin_conn_string, autocommit=True) as conn: