From 665d7df1e6eb6f9f340c27a0b4f9baa7fad2a16d Mon Sep 17 00:00:00 2001
From: Spencer Gibb <sgibb@pivotal.io>
Date: Fri, 29 Oct 2021 15:00:37 -0400
Subject: [PATCH] Adds Visitor pattern to visit each node of Predicate. (#2423)

This allows users to inspect the configuration of predicates and perform work on them.
---
 .../cloud/gateway/handler/AsyncPredicate.java | 28 +++++++-
 .../predicate/AfterRoutePredicateFactory.java |  5 ++
 .../BeforeRoutePredicateFactory.java          |  5 ++
 .../BetweenRoutePredicateFactory.java         |  5 ++
 .../CookieRoutePredicateFactory.java          |  5 ++
 .../handler/predicate/GatewayPredicate.java   | 33 ++++++++-
 .../HeaderRoutePredicateFactory.java          |  5 ++
 .../predicate/HostRoutePredicateFactory.java  |  5 ++
 .../predicate/PathRoutePredicateFactory.java  |  5 ++
 .../predicate/QueryRoutePredicateFactory.java |  5 ++
 .../ReadBodyRoutePredicateFactory.java        |  5 ++
 .../RemoteAddrRoutePredicateFactory.java      |  5 ++
 .../WeightRoutePredicateFactory.java          |  5 ++
 .../cloud/gateway/support/HasConfig.java      | 25 +++++++
 .../cloud/gateway/support/Visitor.java        | 30 ++++++++
 .../GatewayPredicateVisitorTests.java         | 70 +++++++++++++++++++
 16 files changed, 239 insertions(+), 2 deletions(-)
 create mode 100644 spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/HasConfig.java
 create mode 100644 spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/Visitor.java
 create mode 100644 spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/handler/predicate/GatewayPredicateVisitorTests.java

diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/AsyncPredicate.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/AsyncPredicate.java
index 73e43408..e15694eb 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/AsyncPredicate.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/AsyncPredicate.java
@@ -23,13 +23,15 @@ import org.reactivestreams.Publisher;
 import reactor.core.publisher.Mono;
 
 import org.springframework.cloud.gateway.handler.predicate.GatewayPredicate;
+import org.springframework.cloud.gateway.support.HasConfig;
+import org.springframework.cloud.gateway.support.Visitor;
 import org.springframework.util.Assert;
 import org.springframework.web.server.ServerWebExchange;
 
 /**
  * @author Ben Hale
  */
-public interface AsyncPredicate<T> extends Function<T, Publisher<Boolean>> {
+public interface AsyncPredicate<T> extends Function<T, Publisher<Boolean>>, HasConfig {
 
 	default AsyncPredicate<T> and(AsyncPredicate<? super T> other) {
 		return new AndAsyncPredicate<>(this, other);
@@ -47,6 +49,10 @@ public interface AsyncPredicate<T> extends Function<T, Publisher<Boolean>> {
 		return new OrAsyncPredicate<>(this, other);
 	}
 
+	default void accept(Visitor visitor) {
+		visitor.visit(this);
+	}
+
 	static AsyncPredicate<ServerWebExchange> from(Predicate<? super ServerWebExchange> predicate) {
 		return new DefaultAsyncPredicate<>(GatewayPredicate.wrapIfNeeded(predicate));
 	}
@@ -69,6 +75,14 @@ public interface AsyncPredicate<T> extends Function<T, Publisher<Boolean>> {
 			return this.delegate.toString();
 		}
 
+		@Override
+		public void accept(Visitor visitor) {
+			if (delegate instanceof GatewayPredicate) {
+				GatewayPredicate gatewayPredicate = (GatewayPredicate) delegate;
+				gatewayPredicate.accept(visitor);
+			}
+		}
+
 	}
 
 	class NegateAsyncPredicate<T> implements AsyncPredicate<T> {
@@ -110,6 +124,12 @@ public interface AsyncPredicate<T> extends Function<T, Publisher<Boolean>> {
 			return Mono.from(left.apply(t)).flatMap(result -> !result ? Mono.just(false) : Mono.from(right.apply(t)));
 		}
 
+		@Override
+		public void accept(Visitor visitor) {
+			left.accept(visitor);
+			right.accept(visitor);
+		}
+
 		@Override
 		public String toString() {
 			return String.format("(%s && %s)", this.left, this.right);
@@ -135,6 +155,12 @@ public interface AsyncPredicate<T> extends Function<T, Publisher<Boolean>> {
 			return Mono.from(left.apply(t)).flatMap(result -> result ? Mono.just(true) : Mono.from(right.apply(t)));
 		}
 
+		@Override
+		public void accept(Visitor visitor) {
+			left.accept(visitor);
+			right.accept(visitor);
+		}
+
 		@Override
 		public String toString() {
 			return String.format("(%s || %s)", this.left, this.right);
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/AfterRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/AfterRoutePredicateFactory.java
index 3256de86..e8cd073e 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/AfterRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/AfterRoutePredicateFactory.java
@@ -53,6 +53,11 @@ public class AfterRoutePredicateFactory extends AbstractRoutePredicateFactory<Af
 				return now.isAfter(config.getDatetime());
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("After: %s", config.getDatetime());
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/BeforeRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/BeforeRoutePredicateFactory.java
index bae5fb01..47037e8c 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/BeforeRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/BeforeRoutePredicateFactory.java
@@ -51,6 +51,11 @@ public class BeforeRoutePredicateFactory extends AbstractRoutePredicateFactory<B
 				return now.isBefore(config.getDatetime());
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("Before: %s", config.getDatetime());
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/BetweenRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/BetweenRoutePredicateFactory.java
index 8f595ca8..e4c6f089 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/BetweenRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/BetweenRoutePredicateFactory.java
@@ -63,6 +63,11 @@ public class BetweenRoutePredicateFactory extends AbstractRoutePredicateFactory<
 				return now.isAfter(config.getDatetime1()) && now.isBefore(config.getDatetime2());
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("Between: %s and %s", config.getDatetime1(), config.getDatetime2());
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/CookieRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/CookieRoutePredicateFactory.java
index eb556474..7f0363be 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/CookieRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/CookieRoutePredicateFactory.java
@@ -67,6 +67,11 @@ public class CookieRoutePredicateFactory extends AbstractRoutePredicateFactory<C
 				return false;
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("Cookie: name=%s regexp=%s", config.name, config.regexp);
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/GatewayPredicate.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/GatewayPredicate.java
index f781c75e..c373296a 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/GatewayPredicate.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/GatewayPredicate.java
@@ -18,10 +18,12 @@ package org.springframework.cloud.gateway.handler.predicate;
 
 import java.util.function.Predicate;
 
+import org.springframework.cloud.gateway.support.HasConfig;
+import org.springframework.cloud.gateway.support.Visitor;
 import org.springframework.util.Assert;
 import org.springframework.web.server.ServerWebExchange;
 
-public interface GatewayPredicate extends Predicate<ServerWebExchange> {
+public interface GatewayPredicate extends Predicate<ServerWebExchange>, HasConfig {
 
 	@Override
 	default Predicate<ServerWebExchange> and(Predicate<? super ServerWebExchange> other) {
@@ -38,6 +40,10 @@ public interface GatewayPredicate extends Predicate<ServerWebExchange> {
 		return new OrGatewayPredicate(this, wrapIfNeeded(other));
 	}
 
+	default void accept(Visitor visitor) {
+		visitor.visit(this);
+	}
+
 	static GatewayPredicate wrapIfNeeded(Predicate<? super ServerWebExchange> other) {
 		GatewayPredicate right;
 
@@ -64,6 +70,14 @@ public interface GatewayPredicate extends Predicate<ServerWebExchange> {
 			return this.delegate.test(exchange);
 		}
 
+		@Override
+		public void accept(Visitor visitor) {
+			if (delegate instanceof GatewayPredicate) {
+				GatewayPredicate gatewayPredicate = (GatewayPredicate) delegate;
+				gatewayPredicate.accept(visitor);
+			}
+		}
+
 		@Override
 		public String toString() {
 			return this.delegate.getClass().getSimpleName();
@@ -85,6 +99,11 @@ public interface GatewayPredicate extends Predicate<ServerWebExchange> {
 			return !this.predicate.test(t);
 		}
 
+		@Override
+		public void accept(Visitor visitor) {
+			predicate.accept(visitor);
+		}
+
 		@Override
 		public String toString() {
 			return String.format("!%s", this.predicate);
@@ -110,6 +129,12 @@ public interface GatewayPredicate extends Predicate<ServerWebExchange> {
 			return (this.left.test(t) && this.right.test(t));
 		}
 
+		@Override
+		public void accept(Visitor visitor) {
+			left.accept(visitor);
+			right.accept(visitor);
+		}
+
 		@Override
 		public String toString() {
 			return String.format("(%s && %s)", this.left, this.right);
@@ -135,6 +160,12 @@ public interface GatewayPredicate extends Predicate<ServerWebExchange> {
 			return (this.left.test(t) || this.right.test(t));
 		}
 
+		@Override
+		public void accept(Visitor visitor) {
+			left.accept(visitor);
+			right.accept(visitor);
+		}
+
 		@Override
 		public String toString() {
 			return String.format("(%s || %s)", this.left, this.right);
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/HeaderRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/HeaderRoutePredicateFactory.java
index 19e32813..3be06201 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/HeaderRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/HeaderRoutePredicateFactory.java
@@ -79,6 +79,11 @@ public class HeaderRoutePredicateFactory extends AbstractRoutePredicateFactory<H
 				return true;
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("Header: %s regexp=%s", config.header, config.regexp);
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/HostRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/HostRoutePredicateFactory.java
index 767b1540..f9b51114 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/HostRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/HostRoutePredicateFactory.java
@@ -78,6 +78,11 @@ public class HostRoutePredicateFactory extends AbstractRoutePredicateFactory<Hos
 				return false;
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("Hosts: %s", config.getPatterns());
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/PathRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/PathRoutePredicateFactory.java
index 982492ff..dae3e483 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/PathRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/PathRoutePredicateFactory.java
@@ -109,6 +109,11 @@ public class PathRoutePredicateFactory extends AbstractRoutePredicateFactory<Pat
 				}
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("Paths: %s, match trailing slash: %b", config.getPatterns(),
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/QueryRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/QueryRoutePredicateFactory.java
index 6f280d31..d868e5dd 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/QueryRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/QueryRoutePredicateFactory.java
@@ -72,6 +72,11 @@ public class QueryRoutePredicateFactory extends AbstractRoutePredicateFactory<Qu
 				return false;
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("Query: param=%s regexp=%s", config.getParam(), config.getRegexp());
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/ReadBodyRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/ReadBodyRoutePredicateFactory.java
index 09187744..ae4e8ce5 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/ReadBodyRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/ReadBodyRoutePredicateFactory.java
@@ -97,6 +97,11 @@ public class ReadBodyRoutePredicateFactory extends AbstractRoutePredicateFactory
 				}
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("ReadBody: %s", config.getInClass());
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/RemoteAddrRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/RemoteAddrRoutePredicateFactory.java
index 688d36b9..02b5d7be 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/RemoteAddrRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/RemoteAddrRoutePredicateFactory.java
@@ -94,6 +94,11 @@ public class RemoteAddrRoutePredicateFactory
 				return false;
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("RemoteAddrs: %s", config.getSources());
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/WeightRoutePredicateFactory.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/WeightRoutePredicateFactory.java
index fe91fc80..a702a9cd 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/WeightRoutePredicateFactory.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/handler/predicate/WeightRoutePredicateFactory.java
@@ -110,6 +110,11 @@ public class WeightRoutePredicateFactory extends AbstractRoutePredicateFactory<W
 				return false;
 			}
 
+			@Override
+			public Object getConfig() {
+				return config;
+			}
+
 			@Override
 			public String toString() {
 				return String.format("Weight: %s %s", config.getGroup(), config.getWeight());
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/HasConfig.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/HasConfig.java
new file mode 100644
index 00000000..1cb587d4
--- /dev/null
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/HasConfig.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.gateway.support;
+
+public interface HasConfig {
+
+	default Object getConfig() {
+		return null;
+	}
+
+}
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/Visitor.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/Visitor.java
new file mode 100644
index 00000000..7430f95a
--- /dev/null
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/Visitor.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2013-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.gateway.support;
+
+/**
+ * Simple visitor interface that allows users to inspect a graph of objects.
+ *
+ * @author Spencer Gibb
+ * @since 3.1.0
+ */
+@FunctionalInterface
+public interface Visitor {
+
+	void visit(HasConfig hasConfig);
+
+}
diff --git a/spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/handler/predicate/GatewayPredicateVisitorTests.java b/spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/handler/predicate/GatewayPredicateVisitorTests.java
new file mode 100644
index 00000000..fea0a4c4
--- /dev/null
+++ b/spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/handler/predicate/GatewayPredicateVisitorTests.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.gateway.handler.predicate;
+
+import java.util.ArrayList;
+import java.util.function.Predicate;
+
+import org.junit.Test;
+
+import org.springframework.cloud.gateway.handler.AsyncPredicate;
+import org.springframework.cloud.gateway.route.Route;
+import org.springframework.web.server.ServerWebExchange;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Spencer Gibb
+ */
+public class GatewayPredicateVisitorTests {
+
+	@Test
+	public void asyncPredicateVisitVisitsEachNode() {
+		PathRoutePredicateFactory pathRoutePredicateFactory = new PathRoutePredicateFactory();
+		HostRoutePredicateFactory hostRoutePredicateFactory = new HostRoutePredicateFactory();
+		ReadBodyRoutePredicateFactory readBodyRoutePredicateFactory1 = new ReadBodyRoutePredicateFactory();
+		ReadBodyRoutePredicateFactory readBodyRoutePredicateFactory2 = new ReadBodyRoutePredicateFactory();
+		AsyncPredicate<ServerWebExchange> predicate = AsyncPredicate.from(pathRoutePredicateFactory.apply(pathRoutePredicateFactory.newConfig()))
+				.and(AsyncPredicate.from(hostRoutePredicateFactory.apply(hostRoutePredicateFactory.newConfig())))
+				.and(readBodyRoutePredicateFactory1.applyAsync(readBodyRoutePredicateFactory1.newConfig()))
+				.and(readBodyRoutePredicateFactory2.applyAsync(readBodyRoutePredicateFactory2.newConfig()));
+
+		Route route = Route.async().id("git").uri("http://myuri").asyncPredicate(predicate).build();
+		ArrayList<Object> configs = new ArrayList<>();
+		route.getPredicate().accept(p -> configs.add(p.getConfig()));
+
+		assertThat(configs).hasSize(4).hasExactlyElementsOfTypes(PathRoutePredicateFactory.Config.class,
+				HostRoutePredicateFactory.Config.class, ReadBodyRoutePredicateFactory.Config.class,
+				ReadBodyRoutePredicateFactory.Config.class);
+	}
+
+	@Test
+	public void predicateVisitVisitsEachNode() {
+		PathRoutePredicateFactory pathRoutePredicateFactory = new PathRoutePredicateFactory();
+		HostRoutePredicateFactory hostRoutePredicateFactory = new HostRoutePredicateFactory();
+		Predicate<ServerWebExchange> predicate = pathRoutePredicateFactory.apply(pathRoutePredicateFactory.newConfig())
+				.and(hostRoutePredicateFactory.apply(hostRoutePredicateFactory.newConfig()));
+
+		Route route = Route.async().id("git").uri("http://myuri").predicate(predicate).build();
+		ArrayList<Object> configs = new ArrayList<>();
+		route.getPredicate().accept(p -> configs.add(p.getConfig()));
+
+		assertThat(configs).hasSize(2).hasExactlyElementsOfTypes(PathRoutePredicateFactory.Config.class,
+				HostRoutePredicateFactory.Config.class);
+	}
+
+}