Show unexpected type in error (#10)

Author: samuelcolvin

src/common.rs

@@ -11,12 +11,12 @@ pub fn check_args(args: &[DataType], fn_name: &str) -> DataFusionResult<()> {
         return plan_err!("The '{fn_name}' function requires one or more arguments.");
     };
     if !matches!(first, DataType::Utf8 | DataType::LargeUtf8) {
-        return plan_err!("Unexpected argument type to '{fn_name}' at position 1, expected a string.");
+        return plan_err!("Unexpected argument type to '{fn_name}' at position 1, expected a string, got {first:?}.");
     }
     args[1..].iter().enumerate().try_for_each(|(index, arg)| match arg {
         DataType::Utf8 | DataType::LargeUtf8 | DataType::UInt64 | DataType::Int64 => Ok(()),
-        _ => plan_err!(
-            "Unexpected argument type to '{fn_name}' at position {}, expected string or int.",
+        t => plan_err!(
+            "Unexpected argument type to '{fn_name}' at position {}, expected string or int, got {t:?}.",
             index + 2
         ),
     })

tests/main.rs

@@ -185,7 +185,7 @@ async fn test_json_get_str_null() {
 
     assert_eq!(
         e.to_string(),
-        "Error during planning: Unexpected argument type to 'json_get_str' at position 2, expected string or int."
+        "Error during planning: Unexpected argument type to 'json_get_str' at position 2, expected string or int, got Null."
     );
 }
 
@@ -207,6 +207,12 @@ async fn test_json_get_int() {
     assert_eq!(display_val(batches).await, (DataType::Int64, "2".to_string()));
 }
 
+#[tokio::test]
+async fn test_json_get_path() {
+    let batches = run_query(r#"select json_get('{"i": 19}', 'i')::int<20"#).await.unwrap();
+    assert_eq!(display_val(batches).await, (DataType::Boolean, "true".to_string()));
+}
+
 #[tokio::test]
 async fn test_json_get_cast_int() {
     let sql = r#"select json_get('{"foo": 42}', 'foo')::int"#;