Use PathPattern.getPathRemaining in WebFlux fn

This commit uses the newly introduced
`PathPattern.getPathRemaining(String)` in the functional web framework.
With this change, all path predicates can be used for nested router
functions, so the `pathPrefix` predicate is no longer required and has
been removed.

Issue: SPR-15336

spring-webflux/src/test/java/org/springframework/web/reactive/function/server/NestedRouteIntegrationTests.java

@@ -18,6 +18,7 @@ package org.springframework.web.reactive.function.server;
 
 import org.junit.Ignore;
 import org.junit.Test;
+import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 import org.springframework.http.HttpStatus;
@@ -25,9 +26,11 @@ import org.springframework.http.ResponseEntity;
 import org.springframework.web.client.RestTemplate;
 
 import static org.junit.Assert.*;
-import static org.springframework.web.reactive.function.BodyInserters.*;
-import static org.springframework.web.reactive.function.server.RequestPredicates.*;
-import static org.springframework.web.reactive.function.server.RouterFunctions.*;
+import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
+import static org.springframework.web.reactive.function.server.RequestPredicates.path;
+import static org.springframework.web.reactive.function.server.RouterFunctions.nest;
+import static org.springframework.web.reactive.function.server.RouterFunctions.route;
 
 /**
  * @author Arjen Poutsma
@@ -40,9 +43,12 @@ public class NestedRouteIntegrationTests extends AbstractRouterFunctionIntegrati
 	@Override
 	protected RouterFunction<?> routerFunction() {
 		NestedHandler nestedHandler = new NestedHandler();
-		return nest(pathPrefix("/foo"),
+		return nest(path("/foo/"),
 				route(GET("/bar"), nestedHandler::bar)
-				.andRoute(GET("/baz"), nestedHandler::baz));
+						.andRoute(GET("/baz"), nestedHandler::baz))
+				.andNest(GET("/{foo}"),
+						nest(GET("/{bar}"),
+								route(GET("/{baz}"), nestedHandler::variables)));
 	}
 
 
@@ -56,7 +62,6 @@ public class NestedRouteIntegrationTests extends AbstractRouterFunctionIntegrati
 	}
 
 	@Test
-	@Ignore
 	public void baz() throws Exception {
 		ResponseEntity<String> result =
 				restTemplate.getForEntity("http://localhost:" + port + "/foo/baz", String.class);
@@ -65,6 +70,16 @@ public class NestedRouteIntegrationTests extends AbstractRouterFunctionIntegrati
 		assertEquals("baz", result.getBody());
 	}
 
+	@Test
+	@Ignore("SPR-15419")
+	public void variables() throws Exception {
+		ResponseEntity<String> result =
+				restTemplate.getForEntity("http://localhost:" + port + "/1/2/3", String.class);
+
+		assertEquals(HttpStatus.OK, result.getStatusCode());
+		assertEquals("1-2-3", result.getBody());
+	}
+
 
 	private static class NestedHandler {
 
@@ -75,6 +90,13 @@ public class NestedRouteIntegrationTests extends AbstractRouterFunctionIntegrati
 		public Mono<ServerResponse> baz(ServerRequest request) {
 			return ServerResponse.ok().body(fromObject("baz"));
 		}
+
+		public Mono<ServerResponse> variables(ServerRequest request) {
+			Flux<String> responseBody =
+					Flux.just(request.pathVariable("foo"), "-", request.pathVariable("bar"), "-",
+							request.pathVariable("baz"));
+			return ServerResponse.ok().body(responseBody, String.class);
+		}
 	}
 
 }

spring-webflux/src/test/java/org/springframework/web/reactive/function/server/RequestPredicatesTests.java

@@ -163,23 +163,6 @@ public class RequestPredicatesTests {
 		assertFalse(predicate.test(request));
 	}
 
-	@Test
-	public void pathPrefix() throws Exception {
-		RequestPredicate predicate = RequestPredicates.pathPrefix("/foo");
-
-		URI uri = URI.create("http://localhost/foo/bar");
-		MockServerRequest request = MockServerRequest.builder().uri(uri).build();
-		assertTrue(predicate.test(request));
-
-		uri = URI.create("http://localhost/foo");
-		request = MockServerRequest.builder().uri(uri).build();
-		assertTrue(predicate.test(request));
-
-		uri = URI.create("http://localhost/bar");
-		request = MockServerRequest.builder().uri(uri).build();
-		assertFalse(predicate.test(request));
-	}
-
 	@Test
 	public void queryParam() throws Exception {
 		MockServerRequest request = MockServerRequest.builder().queryParam("foo", "bar").build();

spring-webflux/src/test/java/org/springframework/web/reactive/function/server/RouterFunctionsTests.java

@@ -16,6 +16,8 @@
 
 package org.springframework.web.reactive.function.server;
 
+import java.util.Optional;
+
 import org.junit.Test;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
@@ -82,7 +84,7 @@ public class RouterFunctionsTests {
 
 		MockServerRequest request = MockServerRequest.builder().build();
 		RequestPredicate requestPredicate = mock(RequestPredicate.class);
-		when(requestPredicate.test(request)).thenReturn(true);
+		when(requestPredicate.nest(request)).thenReturn(Optional.of(request));
 
 		RouterFunction<ServerResponse> result = RouterFunctions.nest(requestPredicate, routerFunction);
 		assertNotNull(result);
@@ -101,7 +103,7 @@ public class RouterFunctionsTests {
 
 		MockServerRequest request = MockServerRequest.builder().build();
 		RequestPredicate requestPredicate = mock(RequestPredicate.class);
-		when(requestPredicate.test(request)).thenReturn(false);
+		when(requestPredicate.nest(request)).thenReturn(Optional.empty());
 
 		RouterFunction<ServerResponse> result = RouterFunctions.nest(requestPredicate, routerFunction);
 		assertNotNull(result);