handle errors

assets/tests/ruby/call_script_function_that_causes_runtime_error.rb

@@ -0,0 +1,3 @@
+def test_func
+	print("abc" + 5)
+end

assets/tests/ruby/return_via_promise.rb

@@ -0,0 +1,9 @@
+STATE = {
+  'x' => nil
+}
+
+def test_func
+  rust_func.and_then do |x|
+    STATE['x'] = x
+  end
+end

src/lib.rs

@@ -280,9 +280,9 @@ const ENTITY_VAR_NAME: &str = "entity";
 #[derive(Error, Debug)]
 pub enum ScriptingError {
     #[error("script runtime error: {0}")]
-    RuntimeError(Box<dyn std::error::Error>),
+    RuntimeError(Box<dyn std::error::Error + Send>),
     #[error("script compilation error: {0}")]
-    CompileError(Box<dyn std::error::Error>),
+    CompileError(Box<dyn std::error::Error + Send>),
     #[error("no runtime resource present")]
     NoRuntimeResource,
     #[error("no settings resource present")]

src/runtimes/ruby.rs

@@ -12,6 +12,7 @@ use std::{
     thread::{self, JoinHandle},
 };
 
+use anyhow::anyhow;
 use bevy::{
     asset::Asset,
     ecs::{
@@ -19,6 +20,7 @@ use bevy::{
         schedule::ScheduleLabel,
     },
     reflect::TypePath,
+    tasks::futures_lite::io,
 };
 use magnus::{function, method::ReturnValue, IntoValue, Ruby, TryConvert};
 use magnus::{prelude::*, rb_sys::FromRawValue};
@@ -28,7 +30,7 @@ use serde::Deserialize;
 use crate::{
     assets::GetExtensions,
     callback::{FromRuntimeValueWithEngine, IntoRuntimeValueWithEngine},
-    FuncArgs, Runtime,
+    FuncArgs, Runtime, ScriptingError,
 };
 
 #[derive(Resource)]
@@ -263,8 +265,7 @@ impl Runtime for RubyRuntime {
         args: impl for<'a> crate::FuncArgs<'a, Self::Value, Self> + Send + 'static,
     ) -> Result<Self::Value, crate::ScriptingError> {
         let name = name.to_string();
-        Ok(self
-            .ruby_thread
+        self.ruby_thread
             .as_ref()
             .unwrap()
             .execute(Box::new(move |ruby| {
@@ -273,9 +274,14 @@ impl Runtime for RubyRuntime {
                     .into_iter()
                     .map(|a| ruby.get_inner(a.0))
                     .collect();
-                let _: magnus::Value = ruby.class_object().funcall(name, args.as_slice()).unwrap();
-                RubyValue::nil(&ruby)
-            })))
+                let return_value: magnus::Value = ruby
+                    .class_object()
+                    .funcall(name, args.as_slice())
+                    .map_err(|e| {
+                        ScriptingError::RuntimeError(Box::new(io::Error::other(e.to_string())))
+                    })?;
+                Ok(RubyValue::new(return_value))
+            }))
     }
 
     fn call_fn_from_value(

tests/tests.rs

@@ -274,7 +274,7 @@ macro_rules! scripting_tests {
         }
 
         #[test]
-        fn test_call_script_function_that_does_not_exist() {
+        fn test_call_script_function_that_causes_runtime_error() {
             let mut app = build_test_app();
 
             app.add_scripting::<$runtime>(|_| {});
@@ -297,7 +297,7 @@ macro_rules! scripting_tests {
         }
 
         #[test]
-        fn test_script_function_gets_called_from_rust_without_params() {
+        fn test_script_function_gets_called_from_rust() {
             let mut app = build_test_app();
 
             app.add_scripting::<$runtime>(|_| {});
@@ -316,7 +316,7 @@ macro_rules! scripting_tests {
         }
 
         #[test]
-        fn test_promise() {
+        fn test_return_via_promise() {
             let mut app = build_test_app();
 
             app.add_scripting::<$runtime>(|runtime| {