Function assert_engine

lib/sqlalchemy/testing/assertsql.py:478–519

(engine)

@contextlib.contextmanager
def assert_engine(engine):
    asserter = SQLAsserter()

    orig = []

    @event.listens_for(engine, "before_execute")
    def connection_execute(
        conn, clauseelement, multiparams, params, execution_options
    ):
        # grab the original statement + params before any cursor
        # execution
        orig[:] = clauseelement, multiparams, params

    @event.listens_for(engine, "after_cursor_execute")
    def cursor_execute(
        conn, cursor, statement, parameters, context, executemany
    ):
        if not context:
            return
        # then grab real cursor statements and associate them all
        # around a single context
        if (
            asserter.accumulated
            and asserter.accumulated[-1].context is context
        ):
            obs = asserter.accumulated[-1]
        else:
            obs = SQLExecuteObserved(context, orig[0], orig[1], orig[2])
            asserter.accumulated.append(obs)

        obs.statements.append(
            SQLCursorExecuteObserved(
                statement, parameters, context, executemany
            )
        )

    try:
        yield asserter
    finally:
        event.remove(engine, "after_cursor_execute", cursor_execute)
        event.remove(engine, "before_execute", connection_execute)
        asserter._close()