Spring Web Flux (reactive) functional route not working as expected with Kotlin

Question

Hello good people interested in writing spring apps in Kotlin. I am playing with Spring Boot 2.0.0 snapshot and spring-webflux. This piece of code:

@Component
class TestRouter() : RouterFunction<ServerResponse> {
  override fun route(request: ServerRequest) = route(request) {
    "/".route {
      GET("/hello") { ServerResponse.ok().body(BodyInserters.fromObject("World")) }
      "/{id}".route {
        GET("/hello") { ServerResponse.ok().body(BodyInserters.fromObject("World ${request.pathVariable("id")}")) }
      }
    }
  }
}

does not work as expected (at least as I would expect:))

➜  ~ curl -i http://localhost:8080/hello
HTTP/1.1 200 OK
transfer-encoding: chunked
Content-Type: text/plain;charset=UTF-8

World

but:

➜  ~ curl -i http://localhost:8080/1/hello
HTTP/1.1 404 Not Found
content-length: 0

Working case trace:

2017-03-03 00:58:03.865 TRACE 7666 --- [ctor-http-nio-4] o.s.w.r.f.server.RequestPredicates       : Pattern "//**" matches against value "/hello"
2017-03-03 00:58:03.865 DEBUG 7666 --- [ctor-http-nio-4] o.s.w.r.function.server.RouterFunctions  : Nested predicate "//**" matches against "GET /hello"
2017-03-03 00:58:03.865 TRACE 7666 --- [ctor-http-nio-4] o.s.w.r.f.server.RequestPredicates       : Method "GET" matches against value "GET"
2017-03-03 00:58:03.866 TRACE 7666 --- [ctor-http-nio-4] o.s.w.r.f.server.RequestPredicates       : Pattern "/hello" matches against value "/hello"
2017-03-03 00:58:03.866 DEBUG 7666 --- [ctor-http-nio-4] o.s.w.r.function.server.RouterFunctions  : Predicate "(GET && /hello)" matches against "GET /hello"

Not working case trace:

2017-03-03 00:59:26.958 TRACE 7666 --- [ctor-http-nio-1] o.s.w.r.f.server.RequestPredicates       : Pattern "//**" matches against value "/1/hello"
2017-03-03 00:59:26.958 DEBUG 7666 --- [ctor-http-nio-1] o.s.w.r.function.server.RouterFunctions  : Nested predicate "//**" matches against "GET /1/hello"
2017-03-03 00:59:26.958 TRACE 7666 --- [ctor-http-nio-1] o.s.w.r.f.server.RequestPredicates       : Method "GET" matches against value "GET"
2017-03-03 00:59:26.958 TRACE 7666 --- [ctor-http-nio-1] o.s.w.r.f.server.RequestPredicates       : Pattern "/hello" does not match against value "/1/hello"
2017-03-03 00:59:26.959 TRACE 7666 --- [ctor-http-nio-1] o.s.w.r.f.server.RequestPredicates       : Pattern "/{id}/**" matches against value "/1/hello"
2017-03-03 00:59:26.959 DEBUG 7666 --- [ctor-http-nio-1] o.s.w.r.function.server.RouterFunctions  : Nested predicate "/{id}/**" matches against "GET /1/hello"
2017-03-03 00:59:26.959 TRACE 7666 --- [ctor-http-nio-1] o.s.w.r.f.server.RequestPredicates       : Method "GET" matches against value "GET"
2017-03-03 00:59:26.959 TRACE 7666 --- [ctor-http-nio-1] o.s.w.r.f.server.RequestPredicates       : Pattern "/hello" does not match against value "/1/hello"

This seems like a bug (as the "/{id}".route {...} supposedly is using RouterFunctions.nest), but I could be wrong. Your thoughts and help are welcome.

I obviously know that I can make /1/hello work by just writing GET("/{id}/hello") { ... }, but I am interested in the nested .route { ...} variant as it supports my use case of adding nested routes from another location (like a map, etc).

Answer 1

This issue has been fixed in SPR-15310.