Class: RuboCop::Cop::Style::EmptyLiteral

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
FrozenStringLiteral, RangeHelp, RuboCop::Cop::StringLiteralsHelp
Defined in:
lib/rubocop/cop/style/empty_literal.rb

Overview

Checks for the use of a method, the result of which would be a literal, like an empty array, hash, or string.

Examples:

# bad
a = Array.new
a = Array[]
h = Hash.new
h = Hash[]
s = String.new

# good
a = []
h = {}
s = ''

Constant Summary collapse

ARR_MSG = 
'Use array literal `[]` instead of `%<current>s`.'
HASH_MSG = 
'Use hash literal `{}` instead of `%<current>s`.'
STR_MSG = 
'Use string literal `%<prefer>s` instead of `String.new`.'
RESTRICT_ON_SEND = 
%i[new [] Array Hash].freeze

Constants included from FrozenStringLiteral

FrozenStringLiteral::FROZEN_STRING_LITERAL, FrozenStringLiteral::FROZEN_STRING_LITERAL_ENABLED

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods included from FrozenStringLiteral

frozen_string_literal_comment_exists?

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #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, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, 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

#array_node(node) ⇒ Object 



34
 
# File 'lib/rubocop/cop/style/empty_literal.rb', line 34

def_node_matcher :array_node, '(send (const {nil? cbase} :Array) :new (array)?)'

#array_with_block(node) ⇒ Object 



43
 
# File 'lib/rubocop/cop/style/empty_literal.rb', line 43

def_node_matcher :array_with_block, '(block (send (const {nil? cbase} :Array) :new) args _)'

#array_with_index(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/empty_literal.rb', line 54

def_node_matcher :array_with_index, <<~PATTERN
  {
    (send (const {nil? cbase} :Array) :[])
    (send nil? :Array (array))
  }
PATTERN

#hash_node(node) ⇒ Object 



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

def_node_matcher :hash_node, '(send (const {nil? cbase} :Hash) :new)'

#hash_with_block(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/empty_literal.rb', line 46

def_node_matcher :hash_with_block, <<~PATTERN
  {
    (block (send (const {nil? cbase} :Hash) :new) args _)
    (numblock (send (const {nil? cbase} :Hash) :new) ...)
  }
PATTERN

#hash_with_index(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/empty_literal.rb', line 62

def_node_matcher :hash_with_index, <<~PATTERN
  {
    (send (const {nil? cbase} :Hash) :[])
    (send nil? :Hash (array))
  }
PATTERN

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/empty_literal.rb', line 69

def on_send(node)
  return unless (message = offense_message(node))

  add_offense(node, message: message) do |corrector|
    corrector.replace(replacement_range(node), correction(node))
  end
end

#str_node(node) ⇒ Object 



40
 
# File 'lib/rubocop/cop/style/empty_literal.rb', line 40

def_node_matcher :str_node, '(send (const {nil? cbase} :String) :new)'