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

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/style/empty_literal.rb

Overview

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

Constant Summary collapse

ARR_MSG =
'Use array literal [] instead of Array.new.'
HASH_MSG =
'Use hash literal {} instead of Hash.new.'
STR_MSG =
"Use string literal '' instead of String.new."
ARRAY_NODE =

Empty array node

(send (const nil :Array) :new)

s(:send, s(:const, nil, :Array), :new)
HASH_NODE =

Empty hash node

(send (const nil :Hash) :new)

s(:send, s(:const, nil, :Hash), :new)
STR_NODE =

Empty string node

(send (const nil :String) :new)

s(:send, s(:const, nil, :String), :new)

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 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?, #message, 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

#autocorrect(node) ⇒ Object


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# File 'lib/rubocop/cop/style/empty_literal.rb', line 47

def autocorrect(node)
  @corrections << lambda do |corrector|
    name = case node
           when ARRAY_NODE then '[]'
           when HASH_NODE then '{}'
           when STR_NODE then "''"
           end
    corrector.replace(node.loc.expression, name)
  end
end

#on_send(node) ⇒ Object


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# File 'lib/rubocop/cop/style/empty_literal.rb', line 31

def on_send(node)
  return if part_of_ignored_node?(node)

  case node
  when ARRAY_NODE
    add_offense(node, :expression, ARR_MSG)
  when HASH_NODE
    add_offense(node, :expression, HASH_MSG)
  when STR_NODE
    add_offense(node, :expression, STR_MSG)
  end
end