assert_deprecated

# File activesupport/lib/active_support/testing/deprecation.rb, line 6
      def assert_deprecated(match = nil, &block)
        result, warnings = collect_deprecations(&block)
        assert !warnings.empty?, "Expected a deprecation warning within the block but received none"
        if match
          match = Regexp.new(Regexp.escape(match)) unless match.is_a?(Regexp)
          assert warnings.any? { |w| w =~ match }, "No deprecation warning matched #{match}: #{warnings.join(', ')}"
        end
        result
      end