fix: ensure arrow reader returns Unsupported when delete files present in a file scan task

Author: sdd

crates/iceberg/src/arrow/reader.rs

@@ -167,6 +167,14 @@ impl ArrowReader {
         row_group_filtering_enabled: bool,
         row_selection_enabled: bool,
     ) -> Result<ArrowRecordBatchStream> {
+        // TODO: add support for delete files
+        if !task.deletes.is_empty() {
+            return Err(Error::new(
+                ErrorKind::FeatureUnsupported,
+                "Delete files are not yet supported",
+            ));
+        }
+
         // Get the metadata for the Parquet file we need to read and build
         // a reader for the data within
         let parquet_file = file_io.new_input(&task.data_file_path)?;

crates/integration_tests/tests/read_positional_deletes.rs

@@ -17,6 +17,7 @@
 
 //! Integration tests for rest catalog.
 
+use futures::TryStreamExt;
 use iceberg::ErrorKind::FeatureUnsupported;
 use iceberg::{Catalog, TableIdent};
 use iceberg_integration_tests::set_test_fixture;
@@ -35,16 +36,31 @@ async fn test_read_table_with_positional_deletes() {
         .await
         .unwrap();
 
-    let scan = table.scan().build().unwrap();
+    let scan = table
+        .scan()
+        .with_delete_file_processing_enabled(true)
+        .build()
+        .unwrap();
     println!("{:?}", scan);
 
-    assert!(scan
-        .to_arrow()
+    let plan: Vec<_> = scan
+        .plan_files()
+        .await
+        .unwrap()
+        .try_collect()
         .await
-        .is_err_and(|e| e.kind() == FeatureUnsupported));
+        .unwrap();
+    println!("{:?}", plan);
+
+    // Scan plan phase should include delete files in file plan
+    // when with_delete_file_processing_enabled == true
+    assert_eq!(plan[0].deletes.len(), 2);
 
     // 😱 If we don't support positional deletes, we should fail when we try to read a table that
     // has positional deletes. The table has 12 rows, and 2 are deleted, see provision.py
+    let result = scan.to_arrow().await.unwrap().try_collect::<Vec<_>>().await;
+
+    assert!(result.is_err_and(|e| e.kind() == FeatureUnsupported));
 
     // When we get support for it:
     // let batch_stream = scan.to_arrow().await.unwrap();