chore(execution-engine) This commit adds a dedicated triplet resoluti…

…on error for call (#500)

air/src/execution_step/errors/catchable_errors.rs

@@ -86,6 +86,13 @@ pub enum CatchableError {
     /// This error type is occurred when the length functor applied to a value of non-array type.
     #[error("the length functor could applied only to an array-like value, but it's applied to '{0}'")]
     LengthFunctorAppliedToNotArray(JValue),
+
+    /// Call gets non-string JValue resolving triplet parts.
+    #[error("call cannot resolve non-String triplet variable part `{variable_name}` with value '{actual_value}'")]
+    NonStringValueInTripletResolution {
+        variable_name: String,
+        actual_value: JValue,
+    },
 }
 
 impl From<LambdaError> for Rc<CatchableError> {

air/src/execution_step/instructions/call/triplet.rs

@@ -91,10 +91,9 @@ pub(crate) fn resolve_to_string<'i>(
 fn try_jvalue_to_string(jvalue: JValue, variable_name: impl Into<String>) -> ExecutionResult<String> {
     match jvalue {
         JValue::String(s) => Ok(s),
-        _ => Err(CatchableError::IncompatibleJValueType {
+        _ => Err(CatchableError::NonStringValueInTripletResolution {
             variable_name: variable_name.into(),
             actual_value: jvalue,
-            expected_value_type: "string",
         }
         .into()),
     }

air/tests/test_module/features/errors/last_error.rs

@@ -204,7 +204,7 @@ fn variable_names_shown_in_error() {
     assert_eq!(
         trace[1.into()],
         executed_state::scalar(json!(
-            "expected JValue type 'string' for the variable `-relay-`, but got '1'"
+            "call cannot resolve non-String triplet variable part `-relay-` with value '1'"
         ))
     );
 }