Class: RuboCop::Cop::Style::ModuleFunction

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
ConfigurableEnforcedStyle
Defined in:
lib/rubocop/cop/style/module_function.rb

Overview

Checks for use of extend self or module_function in a module.

Supported styles are: module_function (default), extend_self and forbidden.

A couple of things to keep in mind:

  • forbidden style prohibits the usage of both styles

  • in default mode (module_function), the cop won’t be activated when the module contains any private methods

Examples:

EnforcedStyle: module_function (default)

# bad
module Test
  extend self
  # ...
end

# good
module Test
  module_function
  # ...
end

# good
module Test
  extend self
  # ...
  private
  # ...
end

# good
module Test
  class << self
    # ...
  end
end

EnforcedStyle: extend_self

# bad
module Test
  module_function
  # ...
end

# good
module Test
  extend self
  # ...
end

# good
module Test
  class << self
    # ...
  end
end

EnforcedStyle: forbidden

# bad
module Test
  module_function
  # ...
end

# bad
module Test
  extend self
  # ...
end

# bad
module Test
  extend self
  # ...
  private
  # ...
end

# good
module Test
  class << self
    # ...
  end
end

Cop Safety Information:

  • Autocorrection is unsafe (and is disabled by default) because extend self and module_function do not behave exactly the same.

Constant Summary collapse

MODULE_FUNCTION_MSG = 
'Use `module_function` instead of `extend self`.'
EXTEND_SELF_MSG = 
'Use `extend self` instead of `module_function`.'
FORBIDDEN_MSG = 
'Do not use `module_function` or `extend self`.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods included from ConfigurableEnforcedStyle

#alternative_style, #alternative_styles, #ambiguous_style_detected, #correct_style_detected, #detected_style, #detected_style=, #no_acceptable_style!, #no_acceptable_style?, #opposite_style_detected, #style, #style_configured?, #style_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #begin_investigation, 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, #inspect, joining_forces, lint?, match?, #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?, #autocorrect_with_disable_uncorrectable?, #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

#extend_self_node?(node) ⇒ Object 



107
 
# File 'lib/rubocop/cop/style/module_function.rb', line 107

def_node_matcher :extend_self_node?, '(send nil? :extend self)'

#module_function_node?(node) ⇒ Object 



104
 
# File 'lib/rubocop/cop/style/module_function.rb', line 104

def_node_matcher :module_function_node?, '(send nil? :module_function)'

#on_module(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/module_function.rb', line 112

def on_module(node)
  return unless node.body&.begin_type?

  each_wrong_style(node.body.children) do |child_node|
    add_offense(child_node) do |corrector|
      next if style == :forbidden

      if extend_self_node?(child_node)
        corrector.replace(child_node, 'module_function')
      else
        corrector.replace(child_node, 'extend self')
      end
    end
  end
end

#private_directive?(node) ⇒ Object 



110
 
# File 'lib/rubocop/cop/style/module_function.rb', line 110

def_node_matcher :private_directive?, '(send nil? :private ...)'