Class: RuboCop::Cop::Style::StaticClass

Inherits:
Base
  • Object
show all
Includes:
VisibilityHelp
Defined in:
lib/rubocop/cop/style/static_class.rb

Overview

This cop checks for places where classes with only class methods can be replaced with a module. Classes should be used only when it makes sense to create instances out of them.

This cop is marked as unsafe, because it is possible that this class is a parent for some other subclass, monkey-patched with instance methods or a dummy instance is instantiated from it somewhere.

Examples:

# bad
class SomeClass
  def self.some_method
    # body omitted
  end

  def self.some_other_method
    # body omitted
  end
end

# good
module SomeModule
  module_function

  def some_method
    # body omitted
  end

  def some_other_method
    # body omitted
  end
end

# good - has instance method
class SomeClass
  def instance_method; end
  def self.class_method; end
end

Constant Summary collapse

MSG = 
'Prefer modules to classes with only class methods.'

Constants included from VisibilityHelp

VisibilityHelp::VISIBILITY_SCOPES

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Instance Method Details

#on_class(class_node) ⇒ Object 


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# File 'lib/rubocop/cop/style/static_class.rb', line 50

def on_class(class_node)
  return if class_node.parent_class

  add_offense(class_node) if class_convertible_to_module?(class_node)
end