Class: RuboCop::Cop::Style::RedundantArgument

Inherits:

Base

• Object
• Base
• RuboCop::Cop::Style::RedundantArgument

Extended by:

AutoCorrector

Includes:

RangeHelp

Defined in:

lib/rubocop/cop/style/redundant_argument.rb

Overview

Checks for a redundant argument passed to certain methods.

Note	This cop is limited to methods with single parameter.

Method names and their redundant arguments can be configured like this:

Methods:
  join: ''
  sum: 0
  split: ' '
  chomp: "\n"
  chomp!: "\n"
  foo: 2

Examples:

# bad
array.join('')
[1, 2, 3].join("")
array.sum(0)
exit(true)
exit!(false)
string.split(" ")
"first\nsecond".split(" ")
string.chomp("\n")
string.chomp!("\n")
A.foo(2)

# good
array.join
[1, 2, 3].join
array.sum
exit
exit!
string.split
"first second".split
string.chomp
string.chomp!
A.foo

Cop Safety Information:

• This cop is unsafe because of the following limitations:

  1. This cop matches by method names only and hence cannot tell apart methods with same name in different classes.

  2. This cop may be unsafe if certain special global variables (e.g. $;, $/) are set. That depends on the nature of the target methods, of course. For example, the default argument to join is $OUTPUT_FIELD_SEPARATOR (or $,) rather than '', and if that global is changed, '' is no longer a redundant argument.

Constant Summary

MSG =

'Argument %<arg>s is redundant because it is implied by default.'

NO_RECEIVER_METHODS =

%i[exit exit!].freeze

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary

• #on_send(node) ⇒ Object

Methods included from AutoCorrector

support_autocorrect?

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

#on_send(node) ⇒ Object

# File 'lib/rubocop/cop/style/redundant_argument.rb', line 64

def on_send(node)
  return if !NO_RECEIVER_METHODS.include?(node.method_name) && node.receiver.nil?
  return if node.arguments.count != 1
  return unless redundant_argument?(node)

  offense_range = argument_range(node)
  message = format(MSG, arg: node.arguments.first.source)

  add_offense(offense_range, message: message) do |corrector|
    corrector.remove(offense_range)
  end
end