Class: RuboCop::Cop::Lint::MissingSuper

Inherits:
Base
  • Object
show all
Defined in:
lib/rubocop/cop/lint/missing_super.rb

Overview

Checks for the presence of constructors and lifecycle callbacks without calls to ‘super`.

This cop does not consider ‘method_missing` (and `respond_to_missing?`) because in some cases it makes sense to overtake what is considered a missing method. In other cases, the theoretical ideal handling could be challenging or verbose for no actual gain.

Autocorrection is not supported because the position of ‘super` cannot be determined automatically.

Examples:

# bad
class Employee < Person
  def initialize(name, salary)
    @salary = salary
  end
end

# good
class Employee < Person
  def initialize(name, salary)
    super(name)
    @salary = salary
  end
end

# bad
Employee = Class.new(Person) do
  def initialize(name, salary)
    @salary = salary
  end
end

# good
Employee = Class.new(Person) do
  def initialize(name, salary)
    super(name)
    @salary = salary
  end
end

# bad
class Parent
  def self.inherited(base)
    do_something
  end
end

# good
class Parent
  def self.inherited(base)
    super
    do_something
  end
end

Constant Summary collapse

CONSTRUCTOR_MSG = 
'Call `super` to initialize state of the parent class.'
CALLBACK_MSG = 
'Call `super` to invoke callback defined in the parent class.'
STATELESS_CLASSES = 
%w[BasicObject Object].freeze
CLASS_LIFECYCLE_CALLBACKS = 
%i[inherited].freeze
METHOD_LIFECYCLE_CALLBACKS = 
%i[method_added method_removed method_undefined
singleton_method_added singleton_method_removed
singleton_method_undefined].freeze
CALLBACKS = 
(CLASS_LIFECYCLE_CALLBACKS + METHOD_LIFECYCLE_CALLBACKS).to_set.freeze

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

#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?, #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?, #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

#class_new_block(node) ⇒ Object 



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# File 'lib/rubocop/cop/lint/missing_super.rb', line 77

def_node_matcher :class_new_block, <<~RUBY
  ({block numblock}
    (send
      (const {nil? cbase} :Class) :new $_) ...)
RUBY

#on_def(node) ⇒ Object 



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# File 'lib/rubocop/cop/lint/missing_super.rb', line 83

def on_def(node)
  return unless offender?(node)

  if node.method?(:initialize) && inside_class_with_stateful_parent?(node)
    add_offense(node, message: CONSTRUCTOR_MSG)
  elsif callback_method_def?(node)
    add_offense(node, message: CALLBACK_MSG)
  end
end

#on_defs(node) ⇒ Object 



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# File 'lib/rubocop/cop/lint/missing_super.rb', line 93

def on_defs(node)
  return if !callback_method_def?(node) || contains_super?(node)

  add_offense(node, message: CALLBACK_MSG)
end