Class: RuboCop::Cop::InternalAffairs::NodeFirstOrLastArgument

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

Overview

Checks for the use of ‘node.arguments.first` or `node.arguments.last` and suggests the use of `node.first_argument` or `node.last_argument` instead.

Examples:

# bad
node.arguments.first
node.arguments[0]
node.arguments.last
node.arguments[-1]

# good
node.first_argument
node.last_argument

Constant Summary collapse

MSG =
'Use `#%<correct>s` instead of `#%<incorrect>s`.'
RESTRICT_ON_SEND =
%i[arguments].freeze

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

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 RuboCop::Cop::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

#arguments_first_or_last?(node) ⇒ Object



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# File 'lib/rubocop/cop/internal_affairs/node_first_or_last_argument.rb', line 28

def_node_matcher :arguments_first_or_last?, <<~PATTERN
  {
    (send (send !nil? :arguments) ${:first :last})
    (send (send !nil? :arguments) :[] (int ${0 -1}))
  }
PATTERN

#on_send(node) ⇒ Object



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# File 'lib/rubocop/cop/internal_affairs/node_first_or_last_argument.rb', line 35

def on_send(node)
  arguments_first_or_last?(node.parent) do |end_or_index|
    range = range_between(node.loc.selector.begin_pos, node.parent.source_range.end_pos)
    correct = case end_or_index
              when :first, 0 then 'first_argument'
              when :last, -1 then 'last_argument'
              else raise "Unknown end_or_index: #{end_or_index}"
              end
    message = format(MSG, correct: correct, incorrect: range.source)

    add_offense(range, message: message) do |corrector|
      corrector.replace(range, correct)
    end
  end
end