1 files changed, 30 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/module/anonymous.rb b/activesupport/lib/active_support/core_ext/module/anonymous.rb
new file mode 100644
index 0000000000..d1c86b8722
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/module/anonymous.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+class Module
+  # A module may or may not have a name.
+  #
+  #   module M; end
+  #   M.name # => "M"
+  #
+  #   m = Module.new
+  #   m.name # => nil
+  #
+  # +anonymous?+ method returns true if module does not have a name, false otherwise:
+  #
+  #   Module.new.anonymous? # => true
+  #
+  #   module M; end
+  #   M.anonymous?          # => false
+  #
+  # A module gets a name when it is first assigned to a constant. Either
+  # via the +module+ or +class+ keyword or by an explicit assignment:
+  #
+  #   m = Module.new # creates an anonymous module
+  #   m.anonymous?   # => true
+  #   M = m          # m gets a name here as a side-effect
+  #   m.name         # => "M"
+  #   m.anonymous?   # => false
+  def anonymous?
+    name.nil?
+  end
+end