Unnested fields are not filterable when using subqueries. #16695

use datafusion::common::DataFusionError;
use datafusion::prelude::{NdJsonReadOptions, SessionContext};

#[tokio::test]
async fn test_bug() -> Result<(), DataFusionError> {
    let ctx = SessionContext::new();
    ctx.register_json(
        "mock",
        "tests/fixtures/nested.ndjson",
        NdJsonReadOptions::default().file_extension("ndjson")
    ).await?;

    let query = r#"
    WITH one AS (SELECT unnest(metadata) FROM mock),
         two AS (SELECT unnest("__unnest_placeholder(mock.metadata).product") FROM one)
    SELECT * FROM two WHERE "__unnest_placeholder(one.__unnest_placeholder(mock.metadata).product).name" == 'Product Name'
    "#;

    let frame = ctx.sql(query).await?;
    frame.show().await?;

    Ok(())
}