URI query parse errors during parameter extraction throw an unhandled IllegalUriException

[hgiddens]

If parsing the URI query fails during parameter extraction, the resulting IllegalUriException is unhandled, leading to (by default) a 500 being sent back to the client, rather than a 400 as might be expected.

For example, if we curl -i http://localhost:8080/?a== the following route (appropriately bound):

def route: Route =
  parameter('a) { _ =>
    complete(StatusCodes.OK)
  }

We see in the logs:

/?a==
akka.http.scaladsl.model.IllegalUriException: Illegal query: Invalid input '=', expected part, '&' or 'EOI' (line 1, column 3): a==
  ^

The client receives:

± curl -i 'http://localhost:8080/?a=='
HTTP/1.1 500 Internal Server Error
Server: akka-http/10.0.5
Date: Thu, 20 Apr 2017 14:58:37 GMT
Content-Type: text/plain; charset=UTF-8
Content-Length: 35

There was an internal server error.