From 4fe8f1cc5430d9932db65ffa55fe9a373537555a Mon Sep 17 00:00:00 2001
From: Andrew Konchin <andrii.konchyn@oracle.com>
Date: Wed, 18 Dec 2024 16:03:23 +0200
Subject: [PATCH] Fix NoMethodError#message when receiver is an instance of an
 anonymous class

---
 spec/ruby/core/exception/no_method_error_spec.rb      | 11 +++++++++++
 spec/tags/core/exception/no_method_error_tags.txt     |  2 --
 .../truffleruby/core/truffle/exception_operations.rb  | 11 ++++-------
 3 files changed, 15 insertions(+), 9 deletions(-)
 delete mode 100644 spec/tags/core/exception/no_method_error_tags.txt

diff --git a/spec/ruby/core/exception/no_method_error_spec.rb b/spec/ruby/core/exception/no_method_error_spec.rb
index 78fafcaa28f3..9fbaa901295a 100644
--- a/spec/ruby/core/exception/no_method_error_spec.rb
+++ b/spec/ruby/core/exception/no_method_error_spec.rb
@@ -166,6 +166,17 @@ def inspect
       end
     end
 
+    it "uses class' string representation when receiver is a singleton class" do
+      obj = Object.new
+      singleton_class = obj.singleton_class
+
+      begin
+        singleton_class.foo
+      rescue NoMethodError => error
+        error.message.should =~ /\Aundefined method [`']foo' for class #<Class:#<Object:0x\h+>>\Z/
+      end
+    end
+
     it "uses #name when receiver is a module" do
       begin
         NoMethodErrorSpecs::AModule.foo
diff --git a/spec/tags/core/exception/no_method_error_tags.txt b/spec/tags/core/exception/no_method_error_tags.txt
deleted file mode 100644
index 0a1d27b5d5d4..000000000000
--- a/spec/tags/core/exception/no_method_error_tags.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-fails:NoMethodError#message uses class string representation when receiver is an instance of anonymous class
-fails:NoMethodError#message does not call #inspect when calling Exception#message
diff --git a/src/main/ruby/truffleruby/core/truffle/exception_operations.rb b/src/main/ruby/truffleruby/core/truffle/exception_operations.rb
index 8a4513f1769d..41c78b492702 100644
--- a/src/main/ruby/truffleruby/core/truffle/exception_operations.rb
+++ b/src/main/ruby/truffleruby/core/truffle/exception_operations.rb
@@ -79,18 +79,15 @@ def self.receiver_string(receiver)
         when NilClass, TrueClass, FalseClass
           Truffle::Type.rb_inspect(receiver)
         when Class
-          unless receiver.singleton_class?
-            "class #{receiver}"
-          end
-          # otherwise fall through to rb_any_to_s
+          "class #{receiver}"
         when Module
           "module #{receiver}"
         else
           klass = Primitive.metaclass(receiver)
-          if klass.name
-            "an instance of #{klass.name}"
+          unless klass.singleton_class?
+            "an instance of #{klass}"
           end
-          # else fall through to rb_any_to_s
+          # otherwise fall through to rb_any_to_s
         end
       rescue Exception # rubocop:disable Lint/RescueException
         nil