handle panic in rust fn

Author: dr-bonez

duk-derive/Cargo.toml

@@ -14,6 +14,6 @@ repository = "https://github.com/dflemstr/duk"
 proc-macro = true
 
 [dependencies]
-proc-macro2 = "1.0.18"
-quote = "1.0.6"
-syn = { version = "1.0.30", features = ["full", "extra-traits"] }
+proc-macro2 = "1.0.36"
+quote = "1.0.15"
+syn = { version = "1.0.86", features = ["full", "extra-traits"] }

duk-derive/src/lib.rs

@@ -30,7 +30,7 @@ pub fn duktape_fn(_attr: TokenStream, mut item: TokenStream) -> TokenStream {
                     duk::duk_sys::duk_push_error_object(
                         ctx,
                         duk::duk_sys::DUK_ERR_TYPE_ERROR as i32,
-                        std::ffi::CString::new(format!("{}", e)).into_raw(),
+                        std::ffi::CString::new(format!("{}", e)).unwrap_or_default().into_raw(),
                     );
                     duk::duk_sys::duk_throw_raw(ctx);
                     return 0;
@@ -49,7 +49,7 @@ pub fn duktape_fn(_attr: TokenStream, mut item: TokenStream) -> TokenStream {
                     duk::duk_sys::duk_push_error_object(
                         ctx,
                         duk::duk_sys::DUK_ERR_TYPE_ERROR as i32,
-                        std::ffi::CString::new(format!("{}", e)).into_raw(),
+                        std::ffi::CString::new(format!("{}", e)).unwrap_or_default().into_raw(),
                     );
                     duk::duk_sys::duk_throw_raw(ctx);
                     0
@@ -74,9 +74,27 @@ pub fn duktape_fn(_attr: TokenStream, mut item: TokenStream) -> TokenStream {
                     #(
                         #args
                     )*
-                    let res = fn_impl(#(
+                    let res = match std::panic::catch_unwind(|| fn_impl(#(
                         #arg_names,
-                    )*);
+                    )*)) {
+                        Ok(res) => res,
+                        Err(e) => {
+                            let error = if let Some(msg) = e.downcast_ref::<&str>() {
+                                format!("panic: {}", *msg)
+                            } else if let Some(msg) = e.downcast_ref::<String>() {
+                                format!("panic: {}", msg)
+                            } else {
+                                "panic: unknown error".into()
+                            };
+                            duk::duk_sys::duk_push_error_object(
+                                ctx,
+                                duk::duk_sys::DUK_ERR_ERROR as i32,
+                                std::ffi::CString::new(error).unwrap_or_default().into_raw(),
+                            );
+                            duk::duk_sys::duk_throw_raw(ctx);
+                            return 0;
+                        }
+                    };
                     #ret
                 }
             }

src/lib.rs

@@ -1468,6 +1468,11 @@ mod tests {
         input
     }
 
+    #[cfg_attr(feature = "derive", duktape_fn)]
+    fn test_rust_panic_fn() {
+        panic!("panicked successfully")
+    }
+
     #[derive(Debug, serde::Deserialize, serde::Serialize, PartialEq)]
     enum TestEnum {
         A,
@@ -1497,6 +1502,7 @@ mod tests {
 
         add_global_fn!(ctx, test_rust_fn);
         add_global_fn!(ctx, test_rust_complex_fn);
+        add_global_fn!(ctx, test_rust_panic_fn);
 
         let val = ctx.eval_string(r#"test_rust_fn(5.5)"#).unwrap().to_value();
         assert_eq!(Value::String("test 5".to_owned()), val);
@@ -1534,5 +1540,7 @@ mod tests {
             },
             val
         );
+
+        assert!(ctx.eval_string(r"test_rust_panic_fn()").is_err());
     }
 }