Class: RuboCop::Cop::Legion::Singleton::UseInstance

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Defined in:
lib/rubocop/cop/legion/singleton/use_instance.rb

Overview

Detects ‘.new` calls on singleton classes and auto-corrects to `.instance`.

Examples:

# bad
TokenCache.new
Registry.new(arg)

# good
TokenCache.instance
Registry.instance

Constant Summary collapse

RESTRICT_ON_SEND = 
%i[new].freeze
MSG = 
'Use `%<class_name>s.instance` instead of `.new` for singleton classes.'

Instance Method Summary collapse

Instance Method Details

#on_send(node) ⇒ Object 



24
25
26
27
28
29
30
31
32
33
34
35
36
 
# File 'lib/rubocop/cop/legion/singleton/use_instance.rb', line 24

def on_send(node)
  receiver = node.receiver
  return unless receiver&.const_type?

  class_name = receiver.children.last.to_s
  return unless singleton_classes.include?(class_name)

  message = format(MSG, class_name: class_name)
  add_offense(node, message: message, severity: :error) do |corrector|
    # Replace the entire send expression: Receiver.new(args) -> Receiver.instance
    corrector.replace(node, "#{class_name}.instance")
  end
end