module Minitest::Assertions

def assert_equal exp, act, msg = nil
  msg = message(msg, E) { diff exp, act }
  result = assert exp == act, msg
  if nil == exp then
    if Minitest::VERSION =~ /^6/ then
      refute_nil exp, "Use assert_nil if expecting nil."
    else
      warn "DEPRECATED: Use assert_nil if expecting nil from #{_where}. This will fail in Minitest 6."
    end
  end
  result
end