Make {Nil,True,False}Class#singleton_method always raise NameError

{Nil,True,False}Class#singleton_methods always returns [] indicating
that there are no singleton methods defined, so #singleton_method
should be consistent with that.

Fixes [Bug #11064]

1 files changed, 15 insertions, 0 deletions

diff --git a/spec/ruby/core/true/singleton_method_spec.rb b/spec/ruby/core/true/singleton_method_spec.rb
new file mode 100644
index 0000000000..f765054c5f
--- /dev/null
+++ b/spec/ruby/core/true/singleton_method_spec.rb
@@ -0,0 +1,15 @@
+require_relative '../../spec_helper'
+
+describe "TrueClass#singleton_method" do
+  ruby_version_is '3.3' do
+    it "raises regardless of whether TrueClass defines the method" do
+      proc{true.singleton_method(:foo)}.should raise_error(NameError)
+      begin
+        def true.foo; end
+        proc{true.singleton_method(:foo)}.should raise_error(NameError)
+      ensure
+        TrueClass.send(:remove_method, :foo)
+      end
+    end
+  end
+end