gitlab-org--gitlab-foss/danger/frozen_string/Dangerfile

# frozen_string_literal: true

FILE_EXTENSION = ".rb"
MAGIC_COMMENT = "# frozen_string_literal: true"

def get_files_with_no_magic_comment(files)
  files.select do |file|
    file.end_with?(FILE_EXTENSION) &&
      !File.open(file, &:gets)&.start_with?(MAGIC_COMMENT)
  end
end

files_to_fix = get_files_with_no_magic_comment(git.added_files)

if files_to_fix.any?
  warn 'This merge request adds files that do not enforce frozen string literal. ' \
    'See https://gitlab.com/gitlab-org/gitlab-ce/issues/47424 for more information.'

  markdown(<<~MARKDOWN)
    ## Enable Frozen String Literal

    The following files should have `#{MAGIC_COMMENT}` on the first line:

    * #{files_to_fix.map { |path| "`#{path}`" }.join("\n* ")}
  MARKDOWN
end