stdin seems always treated as UTF-8 on Ruby 4.0 on Windows

Author: eregon

language/magic_comment_spec.rb

@@ -45,10 +45,19 @@
 
 describe "Magic comments" do
   describe "in stdin" do
-    it_behaves_like :magic_comments, :locale, -> file {
-      print_at_exit = fixture(__FILE__, "print_magic_comment_result_at_exit.rb")
-      ruby_exe(nil, args: "< #{fixture(__FILE__, file)}", options: "-r#{print_at_exit}")
-    }
+    ruby_version_is ""..."4.0" do
+      it_behaves_like :magic_comments, :locale, -> file {
+        print_at_exit = fixture(__FILE__, "print_magic_comment_result_at_exit.rb")
+        ruby_exe(nil, args: "< #{fixture(__FILE__, file)}", options: "-r#{print_at_exit}")
+      }
+    end
+
+    ruby_version_is "4.0" do
+      it_behaves_like :magic_comments, :UTF8, -> file {
+        print_at_exit = fixture(__FILE__, "print_magic_comment_result_at_exit.rb")
+        ruby_exe(nil, args: "< #{fixture(__FILE__, file)}", options: "-r#{print_at_exit}")
+      }
+    end
   end
 
   platform_is_not :windows do