tests/onegov/core/test_orm.py::test_schema_init_query_count

Flake rate in main: 100.00% (Passed 0 times, Failed 1 times)

Stack Traces | 0.17s run time

postgres_dsn = 'postgresql://postgres@127.0.0.1:42201/test'

    def test_schema_init_query_count(postgres_dsn: str) -> None:
        class Base(DeclarativeBase, ModelBase):
            registry = registry()
    
        # create enough tables so the difference between O(1) and O(N) is clear
        for i in range(20):
            type(f'Table{i}', (Base,), {
                '__tablename__': f'table_{i}',
                'id': mapped_column(Integer, primary_key=True),
            })
    
        mgr = SessionManager(postgres_dsn, Base)
    
        query_count = 0
    
        def count_queries(*args: Any, **kwargs: Any) -> None:
            nonlocal query_count
            query_count += 1
    
        event.listen(mgr.engine, 'before_cursor_execute', count_queries)
        mgr.ensure_schema_exists('test_query_count')
    
        table_count = len(Base.metadata.sorted_tables)
        # O(1) implementation: fixed overhead + 1 get_table_names call
        # O(N) implementation: fixed overhead + 1 has_table call per table
        print('query count:', query_count, 'table count:', table_count)
>       assert query_count < 2 * table_count
E       assert 48 < (2 * 20)

.../onegov/core/test_orm.py:207: AssertionError