How would I go about unittesting a vibe.d app?

[rinfz via Digitalmars-d-learn]

For example, I am trying to test a route. Within the unittest I 
setup the server locally (note: is it possible to start the 
server once for all unit tests?), then call listenHTTP. After the 
listen call I make a client request to localhost with requestHTTP 
and I get the following error:

WARNING: HTTPClientResponse not fully processed before being 
finalized

The code for reference:

unittest {
// imports...
auto listener = setupServer(); // makes the listenHTTP call
scope(exit) listener.stopListening();

requestHTTP(
  environment["HOST"] ~ "/register",
  (scope req) {
    req.method = HTTPMethod.POST;
    req.writeFormBody(["foo": "bar"]);
  },
  (scope res) {
    assert (res.statusCode == 200);
  },
);
}

Note: I am running tests using dub if that is relevant.