defines Module#anonymous?

activesupport/lib/active_support/core_ext/module.rb

 require 'active_support/core_ext/module/aliasing'
 require 'active_support/core_ext/module/introspection'
-
+require 'active_support/core_ext/module/anonymous'
 require 'active_support/core_ext/module/attribute_accessors'
 require 'active_support/core_ext/module/attr_internal'
 require 'active_support/core_ext/module/attr_accessor_with_default'

activesupport/lib/active_support/core_ext/module/anonymous.rb

+class Module  
+  # A module may or may not have a name.
+  #
+  #   module M; end
+  #   M.name # => "M"
+  #
+  #   m = Module.new
+  #   m.name # => ""
+  #
+  # 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 = m          # => m gets a name here as a side-effect
+  #   m.name         # => "M"
+  #
+  def anonymous?
+    name == ''
+  end
+end

activesupport/test/core_ext/module/anonymous_test.rb

+require 'abstract_unit'
+require 'active_support/core_ext/module/anonymous'
+
+class AnonymousTest < ActiveSupport::TestCase
+  test "an anonymous class or module are anonymous" do
+    assert Module.new.anonymous?
+    assert Class.new.anonymous?
+  end
+  
+  test "a named class or module are not anonymous" do
+    assert !Kernel.anonymous?
+    assert !Object.anonymous?
+  end
+end
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