Class: RuboCop::Cop::Lint::UnusedMethodArgument

Inherits:
Cop
  • Object
show all
Includes:
UnusedArgument
Defined in:
lib/rubocop/cop/lint/unused_method_argument.rb

Overview

This cop checks for unused method arguments.

Examples:


def some_method(used, unused, _unused_but_allowed)
  puts used
end

Constant Summary

Constants included from Util

Util::ASGN_NODES, Util::EQUALS_ASGN_NODES, Util::OPERATOR_METHODS, Util::PROC_NEW_NODE, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods included from UnusedArgument

#after_leaving_scope, #autocorrect, #join_force?

Methods inherited from Cop

#add_offense, all, #autocorrect?, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, cop_name_with_namespace, cop_type, #debug?, #display_cop_names?, inherited, #initialize, #join_force?, lint?, non_rails, qualified_cop_name, rails?, #relevant_file?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, block_length, command?, comment_line?, const_name, first_part_of_call_chain, lambda?, lambda_or_proc?, line_range, numeric_range_size, on_node, operator?, parentheses?, proc?, range_with_surrounding_space, source_range, strip_quotes, within_node?

Methods included from PathUtil

issue_deprecation_warning, match_path?, relative_path

Constructor Details

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

Instance Method Details

#check_argument(variable) ⇒ Object


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# File 'lib/rubocop/cop/lint/unused_method_argument.rb', line 16

def check_argument(variable)
  return unless variable.method_argument?
  super
end

#message(variable) ⇒ Object


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# File 'lib/rubocop/cop/lint/unused_method_argument.rb', line 21

def message(variable)
  message = "Unused method argument - `#{variable.name}`."

  unless variable.keyword_argument?
    message << " If it's necessary, use `_` or `_#{variable.name}` " \
               "as an argument name to indicate that it won't be used."
  end

  scope = variable.scope
  all_arguments = scope.variables.each_value.select(&:method_argument?)

  if all_arguments.none?(&:referenced?)
    message << " You can also write as `#{scope.name}(*)` " \
               'if you want the method to accept any arguments ' \
               "but don't care about them."
  end

  message
end