Class: RuboCop::Cop::Style::ConcatArrayLiterals

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

Overview

Enforces the use of ‘Array#push(item)` instead of `Array#concat()` to avoid redundant array literals.

Examples:


# bad
list.concat([foo])
list.concat([bar, baz])
list.concat([qux, quux], [corge])

# good
list.push(foo)
list.push(bar, baz)
list.push(qux, quux, corge)

Constant Summary collapse

MSG = 
'Use `%<prefer>s` instead of `%<current>s`.'
MSG_FOR_PERCENT_LITERALS = 
'Use `push` with elements as arguments without array brackets instead of `%<current>s`.'
RESTRICT_ON_SEND = 
i[concat].freeze

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Instance Method Details

#on_send(node) ⇒ Object Also known as: on_csend

rubocop:disable Metrics



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

def on_send(node)
  return if node.arguments.empty?
  return unless node.arguments.all?(&:array_type?)

  offense = offense_range(node)
  current = offense.source

  if (use_percent_literal = node.arguments.any?(&:percent_literal?))
    if percent_literals_includes_only_basic_literals?(node)
      prefer = preferred_method(node)
      message = format(MSG, prefer: prefer, current: current)
    else
      message = format(MSG_FOR_PERCENT_LITERALS, current: current)
    end
  else
    prefer = preferred_method(node)
    message = format(MSG, prefer: prefer, current: current)
  end

  add_offense(offense, message: message) do |corrector|
    if use_percent_literal
      corrector.replace(offense, prefer)
    else
      corrector.replace(node.loc.selector, 'push')
      node.arguments.each do |argument|
        corrector.remove(argument.loc.begin)
        corrector.remove(argument.loc.end)
      end
    end
  end
end