add doc test

Signed-off-by: jayzhan211 <[email protected]>

datafusion/common/src/utils.rs

@@ -17,6 +17,7 @@
 
 //! This module provides the bisect function, which implements binary search.
 
+use crate::error::_internal_err;
 use crate::{DataFusionError, Result, ScalarValue};
 use arrow::array::{ArrayRef, PrimitiveArray};
 use arrow::buffer::OffsetBuffer;
@@ -337,12 +338,28 @@ pub fn longest_consecutive_prefix<T: Borrow<usize>>(
 }
 
 /// Wrap arrays into a single element `ListArray`.
-/// For example `[1, 2, 3]` would be converted into `[[1, 2, 3]]`
+///
+/// Example:
+/// ```
+/// use arrow::array::{Int32Array, ListArray};
+/// use arrow::datatypes::{Int32Type, Field};
+///
+/// let arr1 = Int32Array::from(vec![1, 2, 3]);
+/// let arr2 = Int32Array::from(vec![4, 5, 6]);
+///
+/// let list_arr = datafusion_common::utils::wrap_into_list_array(&[&arr1, &arr2]).unwrap();
+///
+/// let expected = ListArray::from_iter_primitive::<Int32Type, _, _>(
+///    vec![
+///     Some(vec![Some(1), Some(2), Some(3)]),
+///     Some(vec![Some(4), Some(5), Some(6)]),
+///    ]
+/// );
+///
+/// assert_eq!(list_arr, expected);
 pub fn wrap_into_list_array(arr: &[&dyn Array]) -> Result<ListArray> {
     if arr.is_empty() {
-        return Err(DataFusionError::Internal(
-            "Cannot wrap empty array into list array".to_owned(),
-        ));
+        return _internal_err!("Cannot wrap empty array into list array");
     }
 
     let lens = arr.iter().map(|x| x.len()).collect::<Vec<_>>();