[Bug] Empty request path segment matching

[goodmove]

Problem

1. Path matching behavior depends on the order, in which the endpoints are defined
2. capture[String]('id) matches empty string in paths like /resource/{id}, but capture[Int] does not

How to reproduce

Typed Schema version: v0.12.0

Consider having two API endpoints:

• GET /resource/{id}
• GET /resource/

Currently, the api endpoints definition using typed-schema would be:

  def listBooks =
    prefix('books) :>
      PathEnd :>
      get :>
      key('listBooks) :>
      $$[List[String]]

  def getBook =
    prefix('books) :>
      capture[String]('bookId) :>
      PathEnd :>
      get :>
      key('getBook) :>
      $$[String]

and a handler for that could look like this:

class TestController[F[_]: Sync: RoutedPlus] { self =>
  private val books = Map(
    "1" -> "Book1",
    "2" -> "Book2",
    "3" -> "Book3",
    "4" -> "Book4",
  )

  def routes: H[Response] = MkService[H](api)(self)
  def listBooks(): List[String] = books.values.toList
  def getBook(bookId: String): String = books.getOrElse(bookId, "Not found")

}

where PathEnd checks that all symbols in the request path have been consumed.

Case 1: Definition order

1.1

Final definition:

  def api = getBook <|> listBooks

Actual:

> curl http://localhost:8080/books
< "Not found"

Expected:

> curl http://localhost:8080/books
< ["Book1","Book2","Book3","Book4"]

1.2

Final definition:

  def api = listBooks  <|> getBook

Actual matches expected

> curl http://localhost:8080/books
< ["Book1","Book2","Book3","Book4"]

Case 2: Matching inconsistency

Final definition:

  def api = getBook <|> listBooks

Let's modify getBook to accept Int:

  def getBook =
    prefix('books) :>
      capture[Int]('bookId) :>
      PathEnd :>
      get :>
      key('getBook) :>
      $$[String]

And call the API again (actual matches expected):

> curl http://localhost:8080/books
< ["Book1","Book2","Book3","Book4"]

[REDNBLACK]

Fixed in #442