class RuboCop::Cop::Style::FrozenStringLiteralComment

This cop is designed to help upgrade to Ruby 3.0. It will add the comment `# frozen_string_literal: true` to the top of files to enable frozen string literals. Frozen string literals will be default in Ruby 3.0. The comment will be added below a shebang and encoding comment. The frozen string literal comment is only valid in Ruby 2.3+.

Constants

MSG
MSG_UNNECESSARY
SHEBANG

Public Instance Methods

autocorrect(node) click to toggle source
# File lib/rubocop/cop/style/frozen_string_literal_comment.rb, line 30
def autocorrect(node)
  lambda do |corrector|
    if style == :never
      corrector.remove(range_with_surrounding_space(node.pos, :right))
    else
      last_special_comment = last_special_comment(processed_source)
      if last_special_comment.nil?
        corrector.insert_before(processed_source.tokens[0].pos,
                                "#{FROZEN_STRING_LITERAL_ENABLED}\n")
      else
        corrector.insert_after(last_special_comment.pos,
                               "\n#{FROZEN_STRING_LITERAL_ENABLED}")
      end
    end
  end
end
investigate(processed_source) click to toggle source
# File lib/rubocop/cop/style/frozen_string_literal_comment.rb, line 19
def investigate(processed_source)
  return if style == :when_needed && target_ruby_version < 2.3
  return if processed_source.tokens.empty?

  if frozen_string_literal_comment_exists?
    check_for_no_comment(processed_source)
  else
    check_for_comment(processed_source)
  end
end

Private Instance Methods

check_for_comment(processed_source) click to toggle source
# File lib/rubocop/cop/style/frozen_string_literal_comment.rb, line 53
def check_for_comment(processed_source)
  offense(processed_source) unless style == :never
end
check_for_no_comment(processed_source) click to toggle source
# File lib/rubocop/cop/style/frozen_string_literal_comment.rb, line 49
def check_for_no_comment(processed_source)
  unnecessary_comment_offense(processed_source) if style == :never
end
frozen_string_literal_comment(processed_source) click to toggle source
# File lib/rubocop/cop/style/frozen_string_literal_comment.rb, line 72
def frozen_string_literal_comment(processed_source)
  processed_source.tokens.find do |token|
    token.text.start_with?(FrozenStringLiteral::FROZEN_STRING_LITERAL)
  end
end
last_special_comment(processed_source) click to toggle source
# File lib/rubocop/cop/style/frozen_string_literal_comment.rb, line 57
def last_special_comment(processed_source)
  token_number = 0
  if processed_source.tokens[token_number].text.start_with?(SHEBANG)
    token = processed_source.tokens[token_number]
    token_number += 1
  end

  if processed_source.tokens[token_number].text =~
     Encoding::ENCODING_PATTERN
    token = processed_source.tokens[token_number]
  end

  token
end
offense(processed_source) click to toggle source
# File lib/rubocop/cop/style/frozen_string_literal_comment.rb, line 78
def offense(processed_source)
  last_special_comment = last_special_comment(processed_source)
  range = source_range(processed_source.buffer, 0, 0)

  add_offense(last_special_comment, location: range)
end
unnecessary_comment_offense(processed_source) click to toggle source
# File lib/rubocop/cop/style/frozen_string_literal_comment.rb, line 85
def unnecessary_comment_offense(processed_source)
  frozen_string_literal_comment =
    frozen_string_literal_comment(processed_source)

  add_offense(frozen_string_literal_comment,
              location: frozen_string_literal_comment.pos,
              message: MSG_UNNECESSARY)
end