Function read_empty_table

datafusion/core/src/datasource/listing/table.rs:374–415

()

    #[tokio::test]
    async fn read_empty_table() -> Result<()> {
        let ctx = SessionContext::new();
        let path = String::from("table/p1=v1/file.json");
        register_test_store(&ctx, &[(&path, 100)]);

        let format = JsonFormat::default();
        let ext = format.get_ext();

        let opt = ListingOptions::new(Arc::new(format))
            .with_file_extension(ext)
            .with_table_partition_cols(vec![(String::from("p1"), DataType::Utf8)])
            .with_target_partitions(4);

        let table_path = ListingTableUrl::parse("test:///table/")?;
        let file_schema =
            Arc::new(Schema::new(vec![Field::new("a", DataType::Boolean, false)]));
        let config = ListingTableConfig::new(table_path)
            .with_listing_options(opt)
            .with_schema(file_schema);
        let table = ListingTable::try_new(config)?;

        assert_eq!(
            columns(&table.schema()),
            vec!["a".to_owned(), "p1".to_owned()]
        );

        // this will filter out the only file in the store
        let filter = Expr::not_eq(col("p1"), lit("v1"));

        let scan = table
            .scan(&ctx.state(), None, &[filter], None)
            .await
            .expect("Empty execution plan");

        assert!(scan.is::<EmptyExec>());
        assert_eq!(
            columns(&scan.schema()),
            vec!["a".to_owned(), "p1".to_owned()]
        );

        Ok(())
    }

    async fn load_table(
        ctx: &SessionContext,