3 files changed, 25 insertions, 18 deletions
diff --git a/lib/syntax_suggest/api.rb b/lib/syntax_suggest/api.rb
index 65660ec5e5..46c9c8adac 100644
--- a/lib/syntax_suggest/api.rb
+++ b/lib/syntax_suggest/api.rb
@@ -227,6 +227,7 @@ require_relative "lex_all"
 require_relative "code_line"
 require_relative "code_block"
 require_relative "block_expand"
+require_relative "mini_stringio"
 require_relative "priority_queue"
 require_relative "unvisited_lines"
 require_relative "around_block_scan"
diff --git a/lib/syntax_suggest/core_ext.rb b/lib/syntax_suggest/core_ext.rb
index c299627bb7..94f57ba605 100644
--- a/lib/syntax_suggest/core_ext.rb
+++ b/lib/syntax_suggest/core_ext.rb
@@ -3,24 +3,6 @@
 # Ruby 3.2+ has a cleaner way to hook into Ruby that doesn't use `require`
 if SyntaxError.method_defined?(:detailed_message)
   module SyntaxSuggest
-    # Mini String IO [Private]
-    #
-    # Acts like a StringIO with reduced API, but without having to require that
-    # class.
-    class MiniStringIO
-      def initialize(isatty: $stderr.isatty)
-        @string = +""
-        @isatty = isatty
-      end
-
-      attr_reader :isatty
-      def puts(value = $/, **)
-        @string << value
-      end
-
-      attr_reader :string
-    end
-
     # SyntaxSuggest.module_for_detailed_message [Private]
     #
     # Used to monkeypatch SyntaxError via Module.prepend
diff --git a/lib/syntax_suggest/mini_stringio.rb b/lib/syntax_suggest/mini_stringio.rb
new file mode 100644
index 0000000000..ee5192ba90
--- /dev/null
+++ b/lib/syntax_suggest/mini_stringio.rb
@@ -0,0 +1,24 @@
+module SyntaxSuggest
+  # Mini String IO [Private]
+  #
+  # Acts like a StringIO with reduced API, but without having to require that
+  # class.
+  class MiniStringIO
+    EMPTY_ARG = Object.new
+
+    def initialize(isatty: $stderr.isatty)
+      @string = +""
+      @isatty = isatty
+    end
+
+    attr_reader :isatty
+    def puts(value = EMPTY_ARG, **)
+      if !value.equal?(EMPTY_ARG)
+        @string << value
+      end
+      @string << $/
+    end
+
+    attr_reader :string
+  end
+end