class RuboCop::Cop::Naming::ClassAndModuleCamelCase

end
class module_parent::MyModule
end
module MyModule
end
class MyClass
# good
end
module My_Module
end
class My_Class
# bad
@example
`my_class`, ‘my_class::User`, `App::my_class`, `App::my_class::User`, etc.
eg. Adding `my_class` to the `AllowedNames` config will allow names like
These names can be full class/module names or part of the name.
Its default value is `[’module_parent’]‘.
`AllowedNames` config takes an array of permitted names.
an underscore in them.
Checks for class and module names with

def on_class(node) 

def on_class(node)
  return unless node.loc.name.source.include?('_')
  allowed = /#{cop_config['AllowedNames'].join('|')}/
  name = node.loc.name.source.gsub(allowed, '')
  return unless name.include?('_')
  add_offense(node.loc.name)
end