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

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

Overview

This cop checks for a redundant argument passed to certain methods.

Limitations:

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

  2. This cop is limited to methods with single parameter.

  3. This cop is unsafe if certain special global variables (e.g. `$;`, `$/`) are set. That depends on the nature of the target methods, of course.

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

Methods:

join: ''
split: ' '
chomp: "\n"
chomp!: "\n"
foo: 2

Examples:

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

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

Constant Summary collapse

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

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 inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #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, 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?, #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 


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# File 'lib/rubocop/cop/style/redundant_argument.rb', line 49

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

  add_offense(node, message: format(MSG, arg: node.arguments.first.source)) do |corrector|
    corrector.remove(argument_range(node))
  end
end