RSpec::Matchers.define :have_linux_line_endings do
  match do |file|
    !file.content.include?("\r\n")
  end

  failure_message do |file|
    "Expected file '#{file.name}' to have linux line endings, but it didn't"
  end

  failure_message_when_negated do |file|
    "Expected file '#{file.name}' to not have linux line endings, but it did"
  end
end