Class: RuboCop::Cop::Style::ClassVars

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/style/class_vars.rb

Overview

This cop checks for uses of class variables. Offenses are signaled only on assignment to class variables to reduce the number of offenses that would be reported.

You have to be careful when setting a value for a class variable; if a class has been inherited, changing the value of a class variable also affects the inheriting classes. This means that it’s almost always better to use a class instance variable instead.

Examples:

# bad
class A
  @@test = 10
end

# good
class A
  @test = 10
end

class A
  def test
    @@test # you can access class variable without offence
  end
end

Constant Summary collapse

MSG = 
'Replace class var %<class_var>s with a class ' \
'instance var.'.freeze

Constants included from Util

Util::ASGN_NODES, Util::CONDITIONAL_NODES, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::LOGICAL_OPERATOR_NODES, Util::MODIFIER_NODES, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, #correct, department, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from AST::Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, operator?, parentheses?, same_line?, to_string_literal, to_supported_styles, tokens

Methods included from PathUtil

absolute?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

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

Instance Method Details

#message(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/class_vars.rb', line 41

def message(node)
  class_var, = *node
  format(MSG, class_var: class_var)
end

#on_cvasgn(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/class_vars.rb', line 37

def on_cvasgn(node)
  add_offense(node, location: :name)
end