--log('hello test case')

function check(output, ...)
  local s = tostring(solution(...))
  local inputs = table.concat({...}, ", ")
  if s == output then
    log("OK: "..inputs.." => "..output)
  else
    log("Oops: "..inputs.." => "..s.." (expected: "..output..")")
    error("verification failed")
  end
end

i = [[<a href="https://play.google.com/store/apps/details?id=de.appwerft.tinybrain"><img src="http://tinybrain.de/tb/images/tinybrain-qrlogo.png" width="120" height="120"></a><br>]]

o = [[<a href="http://tinybrain.de/tb/images/tinybrain-qrlogo.png"><img src="http://tinybrain.de/tb/images/tinybrain-qrlogo.png" width="120" height="120"></a><br>]]

check(o, i, "copy src to href")

return true -- hmm. so easy to forget... but we need it!