class Shoulda::Matchers::ActiveRecord::HaveDbIndexMatcher

def correct_unique?
  return true unless @options.key?(:unique)
  is_unique = matched_index.unique
  is_unique = !is_unique unless @options[:unique]
  unless is_unique
    @missing = "#{table_name} has an index named #{matched_index.name} " <<
    "of unique #{matched_index.unique}, not #{@options[:unique]}."
  end
  is_unique
end