Cannot cast string dictionary to binary view #8841
Description
Describe the bug
When casting a dictionary with string value to binary view, run into an unexpected error.
To Reproduce
This test should pass:
// arrow-cast/src/cast/mod.rs
#[test]
fn test_string_dict_to_binary_view() {
let values = StringArray::from_iter(VIEW_TEST_DATA);
let keys = Int8Array::from_iter([Some(1), Some(0), None, Some(3), None, Some(1), Some(4)]);
let string_dict_array =
DictionaryArray::<Int8Type>::try_new(keys, Arc::new(values)).unwrap();
let casted = cast(&string_dict_array, &DataType::BinaryView).unwrap();
assert_eq!(casted.data_type(), &DataType::BinaryView);
}Currently failing:
thread 'cast::tests::test_string_dict_to_binary_view' (4994586) panicked at arrow-cast/src/cast/mod.rs:6651:70:
called `Result::unwrap()` on an `Err` value: ComputeError("Internal Error: Cannot cast BinaryView to BinaryArray of expected type")
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
test cast::tests::test_string_dict_to_binary_view ... FAILEDExpected behavior
Should successfully cast to a binary view.
Additional context
Discovered in DataFusion: apache/datafusion#18662 (comment)
Related code is here:
arrow-rs/arrow-cast/src/cast/dictionary.rs
Lines 107 to 125 in 2bc269c
- It's likely the same will happen for vice-versa situation, i.e. binary dictionary to string view (see above arm)
Related PR: #5871