fix: re-add test_utils module

Author: Sl1mb0

host/tests/integration_tests/mod.rs

@@ -1,2 +1,3 @@
 mod python;
 mod rust;
+mod test_utils;

host/tests/integration_tests/python/runtime/http.rs

@@ -17,7 +17,10 @@ use tokio::runtime::Handle;
 use wasmtime_wasi_http::types::DEFAULT_FORBIDDEN_HEADERS;
 use wiremock::{Mock, MockServer, ResponseTemplate, matchers};
 
-use crate::integration_tests::python::test_utils::{python_component, python_scalar_udf};
+use crate::integration_tests::{
+    python::test_utils::{python_component, python_scalar_udf},
+    test_utils::ColumnarValueExt,
+};
 
 #[tokio::test(flavor = "multi_thread")]
 async fn test_requests_simple() {

host/tests/integration_tests/test_utils.rs

@@ -0,0 +1,22 @@
+use arrow::array::ArrayRef;
+use datafusion_expr::ColumnarValue;
+
+/// Extension trait for [`ColumnarValue`] for easier testing.
+pub(crate) trait ColumnarValueExt {
+    /// Extracts [`ColumnarValue::Array`] variant.
+    ///
+    /// # Panic
+    /// Panics if this is not an array.
+    #[track_caller]
+    fn unwrap_array(self) -> ArrayRef;
+}
+
+impl ColumnarValueExt for ColumnarValue {
+    #[track_caller]
+    fn unwrap_array(self) -> ArrayRef {
+        match self {
+            Self::Array(array) => array,
+            Self::Scalar(_) => panic!("expected an array but got a scalar"),
+        }
+    }
+}