Optional query parameters do not work as expected

[jroylance]

Routes with optional query parameters return a 400 response when the query parameter is not provided. Below is a minimal repro example:

package app

import scala.annotation.nowarn

@nowarn
object MinimalApplication extends cask.MainRoutes {
  @cask.get("/")
  def hello(param: Option[String]) = {
    "Hello World!"
  }

  initialize()
}

I ran this application and then ran the following in my terminal:

$ curl http://localhost:8080?param=asdf
Hello World!
$ curl http://localhost:8080
Missing argument: (param: Option[String])

Arguments provided did not match expected signature:

hello
  param  Option[String]

The expected behavior is that both curl requests succeed.

[jroylance]

Found a workaround, or perhaps the intended way of using optional query parameters - by using a default of None:

package app

import scala.annotation.nowarn

@nowarn
object MinimalApplication extends cask.MainRoutes {
  @cask.get("/")
  def hello(param: Option[String] = None) = {
    "Hello World!"
  }

  initialize()
}

This solves my problem, and apologies for the spam