From 4cb60fa26649a917b40eeae29e8139e2dd269ab2 Mon Sep 17 00:00:00 2001
From: Benoit Daloze <eregontp@gmail.com>
Date: Wed, 2 Mar 2022 17:14:12 +0100
Subject: [PATCH] Adapt ExecJS::GraalJSRuntime to foreign exception changes in
 TruffleRuby

* Foreign exceptions are no longer translated to ::RuntimeError but
  remain as foreign exceptions and are given the class Polyglot::ForeignException.
* The backtrace can be nil, notably when throwing a JS string.
---
 lib/execjs/graaljs_runtime.rb | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/execjs/graaljs_runtime.rb b/lib/execjs/graaljs_runtime.rb
index 01d652d..d3cab2a 100644
--- a/lib/execjs/graaljs_runtime.rb
+++ b/lib/execjs/graaljs_runtime.rb
@@ -46,16 +46,18 @@ def call(source, *args)
 
       private
 
+      ForeignException = defined?(Polyglot::ForeignException) ? Polyglot::ForeignException : ::RuntimeError
+
       def translate
         convert_js_to_ruby yield
-      rescue ::RuntimeError => e
+      rescue ForeignException => e
         if e.message.start_with?('SyntaxError:')
           error_class = ExecJS::RuntimeError
         else
           error_class = ExecJS::ProgramError
         end
 
-        backtrace = e.backtrace.map { |line| line.sub('(eval)', '(execjs)') }
+        backtrace = (e.backtrace || []).map { |line| line.sub('(eval)', '(execjs)') }
         raise error_class, e.message, backtrace
       end