Polish Kotlin Web functional DSL

Issue: SPR-15065

spring-web-reactive/src/main/kotlin/org/springframework/web/reactive/function/server/RouterFunctionExtensions.kt

@@ -13,12 +13,12 @@ import reactor.core.publisher.Mono
  * fun route(request: ServerRequest) = route(request) {
  * 		accept(TEXT_HTML).apply {
  * 			(GET("/user/") or GET("/users/")) { findAllView() }
- * 			GET("/user/{login}") { findViewById() }
+ * 			GET("/user/{login}", ::findViewById)
  * 		}
  * 		accept(APPLICATION_JSON).apply {
  * 			(GET("/api/user/") or GET("/api/users/")) { findAll() }
- * 			POST("/api/user/") { create() }
- * 			POST("/api/user/{login}") { findOne() }
+ * 			POST("/api/user/", ::create)
+ * 			POST("/api/user/{login}", ::findOne)
  * 		}
  * 	}
  * ```
@@ -35,62 +35,62 @@ class RouterDsl {
 	val children = mutableListOf<RouterDsl>()
 	val routes = mutableListOf<RouterFunction<ServerResponse>>()
 
-	operator fun RequestPredicate.invoke(f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(this, f())
-	}
-
 	infix fun RequestPredicate.and(other: RequestPredicate): RequestPredicate = this.and(other)
 
 	infix fun RequestPredicate.or(other: RequestPredicate): RequestPredicate = this.or(other)
 
 	operator fun RequestPredicate.not(): RequestPredicate = this.negate()
 
-	fun GET(pattern: String, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.GET(pattern), f())
+	operator fun RequestPredicate.invoke(f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(this, HandlerFunction { f(it) })
+	}
+
+	fun GET(pattern: String, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.GET(pattern), HandlerFunction { f(it) } )
 	}
 
-	fun HEAD(pattern: String, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.HEAD(pattern), f())
+	fun HEAD(pattern: String, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.HEAD(pattern), HandlerFunction { f(it) })
 	}
 
-	fun POST(pattern: String, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.POST(pattern), f())
+	fun POST(pattern: String, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.POST(pattern), HandlerFunction { f(it) })
 	}
 
-	fun PUT(pattern: String, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.PUT(pattern), f())
+	fun PUT(pattern: String, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.PUT(pattern), HandlerFunction { f(it) })
 	}
 
-	fun PATCH(pattern: String, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.PATCH(pattern), f())
+	fun PATCH(pattern: String, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.PATCH(pattern), HandlerFunction { f(it) })
 	}
 
-	fun DELETE(pattern: String, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.DELETE(pattern), f())
+	fun DELETE(pattern: String, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.DELETE(pattern), HandlerFunction { f(it) })
 	}
 
-	fun OPTIONS(pattern: String, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.OPTIONS(pattern), f())
+	fun OPTIONS(pattern: String, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.OPTIONS(pattern), HandlerFunction { f(it) })
 	}
 
-	fun accept(vararg mediaType: MediaType, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.accept(*mediaType), f())
+	fun accept(mediaType: MediaType, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.accept(mediaType), HandlerFunction { f(it) })
 	}
 
-	fun contentType(vararg mediaType: MediaType, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.contentType(*mediaType), f())
+	fun contentType(mediaType: MediaType, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.contentType(mediaType), HandlerFunction { f(it) })
 	}
 
-	fun headers(headerPredicate: (ServerRequest.Headers)->Boolean, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.headers(headerPredicate), f())
+	fun headers(headerPredicate: (ServerRequest.Headers)->Boolean, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.headers(headerPredicate), HandlerFunction { f(it) })
 	}
 
-	fun method(httpMethod: HttpMethod, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.method(httpMethod), f())
+	fun method(httpMethod: HttpMethod, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.method(httpMethod), HandlerFunction { f(it) })
 	}
 
-	fun path(pattern: String, f: () -> HandlerFunction<ServerResponse>) {
-		routes += RouterFunctions.route(RequestPredicates.path(pattern), f())
+	fun path(pattern: String, f: (ServerRequest) -> Mono<ServerResponse>) {
+		routes += RouterFunctions.route(RequestPredicates.path(pattern), HandlerFunction { f(it) })
 	}
 
 	fun resources(path: String, location: Resource) {

spring-web-reactive/src/test/kotlin/org/springframework/web/reactive/function/server/RouterFunctionExtensionsTests.kt

@@ -92,23 +92,22 @@ class RouterFunctionExtensionsTests {
 				.verifyComplete()
 	}
 
-
 	class FooController : RouterFunction<ServerResponse> {
 
-		override fun route(request: ServerRequest) = route(request) {
-			(GET("/foo/") or GET("/foos/")) { handle() }
+		override fun route(req: ServerRequest) = route(req) {
+			(GET("/foo/") or GET("/foos/")) { handle(req) }
 			accept(APPLICATION_JSON).apply {
-				POST("/api/foo/") { handle() }
-				PUT("/api/foo/") { handle() }
-				DELETE("/api/foo/") { handle() }
+				POST("/api/foo/", ::handle)
+				PUT("/api/foo/", ::handle)
+				DELETE("/api/foo/", ::handle)
 			}
-			accept(APPLICATION_ATOM_XML) { handle() }
-			contentType(APPLICATION_OCTET_STREAM) { handle() }
-			method(HttpMethod.PATCH) { handle() }
+			accept(APPLICATION_ATOM_XML, ::handle)
+			contentType(APPLICATION_OCTET_STREAM) { handle(req) }
+			method(HttpMethod.PATCH) { handle(req) }
 			headers({ it.accept().contains(APPLICATION_JSON) }).apply {
-				GET("/api/foo/") { handle() }
+				GET("/api/foo/", ::handle)
 			}
-			headers({ it.header("bar").isNotEmpty() }) { handle() }
+			headers({ it.header("bar").isNotEmpty() }, ::handle)
 			resources("/org/springframework/web/reactive/function/**",
 					ClassPathResource("/org/springframework/web/reactive/function/response.txt"))
 			resources {
@@ -119,11 +118,10 @@ class RouterFunctionExtensionsTests {
 					Mono.empty()
 				}
 			}
-			path("/baz") { handle() }
+			path("/baz") { handle(req) }
 		}
-
-		fun handle() = HandlerFunction { ok().build() }
-
 	}
-
 }
+
+private fun handle(req: ServerRequest) = ok().build()
+