Function plan_count_wildcard

datafusion/core/src/execution/session_state.rs:2567–2583

A helper method for planning count wildcard with or without expr planners.

(
            with_expr_planners: bool,
        )

    async fn test_with_expr_planners() -> Result<()> {
        // A helper method for planning count wildcard with or without expr planners.
        async fn plan_count_wildcard(
            with_expr_planners: bool,
        ) -> Result<Arc<dyn ExecutionPlan>> {
            let mut context_provider = MyContextProvider::new().with_table(
                "t",
                provider_as_source(Arc::new(EmptyTable::new(Schema::empty().into()))),
            );
            if with_expr_planners {
                context_provider = context_provider.with_expr_planners();
            }

            let state = &context_provider.state;
            let statement =
                state.sql_to_statement("select count(*) from t", &Dialect::MySQL)?;
            let plan = SqlToRel::new(&context_provider).statement_to_plan(statement)?;
            state.create_physical_plan(&plan).await
        }

        // Planning count wildcard without expr planners should fail.
        let got = plan_count_wildcard(false).await;