Merge pull request #28569 from christophejan:fix/28567

* gh-28567:
  Polish
  Add minimal Kotlin DSL RouterFunction attributes support
  Add test case on nested RouterFunction attributes

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -586,6 +586,30 @@ class CoRouterFunctionDsl internal constructor (private val init: (CoRouterFunct
 		}
 	}
 
+	/**
+	 * Add an attribute with the given name and value to the last route built with this builder.
+	 * @param name the attribute name
+	 * @param value the attribute value
+-	 * @since 6.0
+	 */
+	fun withAttribute(name: String, value: Any) {
+		builder.withAttribute(name, value)
+	}
+
+	/**
+	 * Manipulate the attributes of the last route built with the given consumer.
+	 *
+	 * The map provided to the consumer is "live", so that the consumer can be used
+	 * to [overwrite][MutableMap.put] existing attributes,
+	 * [remove][MutableMap.remove] attributes, or use any of the other
+	 * [MutableMap] methods.
+	 * @param attributesConsumer a function that consumes the attributes map
+	 * @since 6.0
+	 */
+	fun withAttributes(attributesConsumer: (MutableMap<String, Any>) -> Unit) {
+		builder.withAttributes(attributesConsumer)
+	}
+
 	/**
 	 * Return a composed routing function created from all the registered routes.
 	 */

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -702,6 +702,30 @@ class RouterFunctionDsl internal constructor (private val init: RouterFunctionDs
 		builder.onError({it is E}, responseProvider)
 	}
 
+	/**
+	 * Add an attribute with the given name and value to the last route built with this builder.
+	 * @param name the attribute name
+	 * @param value the attribute value
+	 * @since 6.0
+	 */
+	fun withAttribute(name: String, value: Any) {
+		builder.withAttribute(name, value)
+	}
+
+	/**
+	 * Manipulate the attributes of the last route built with the given consumer.
+	 *
+	 * The map provided to the consumer is "live", so that the consumer can be used
+	 * to [overwrite][MutableMap.put] existing attributes,
+	 * [remove][MutableMap.remove] attributes, or use any of the other
+	 * [MutableMap] methods.
+	 * @param attributesConsumer a function that consumes the attributes map
+	 * @since 6.0
+	 */
+	fun withAttributes(attributesConsumer: (MutableMap<String, Any>) -> Unit) {
+		builder.withAttributes(attributesConsumer)
+	}
+
 	/**
 	 * Return a composed routing function created from all the registered routes.
 	 * @since 5.1

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -16,43 +16,60 @@
 
 package org.springframework.web.reactive.function.server;
 
+import java.util.Deque;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import reactor.core.publisher.Mono;
 
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
 
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.entry;
-
 /**
  * @author Arjen Poutsma
  */
 class AttributesTestVisitor implements RouterFunctions.Visitor {
 
+	private Deque<Map<String, Object>> nestedAttributes = new LinkedList<>();
+
 	@Nullable
 	private Map<String, Object> attributes;
 
+	private List<List<Map<String, Object>>> routerFunctionsAttributes = new LinkedList<>();
+
 	private int visitCount;
 
+	public List<List<Map<String, Object>>> routerFunctionsAttributes() {
+		return this.routerFunctionsAttributes;
+	}
+
 	public int visitCount() {
 		return this.visitCount;
 	}
 
 	@Override
 	public void startNested(RequestPredicate predicate) {
+		nestedAttributes.addFirst(attributes);
+		attributes = null;
 	}
 
 	@Override
 	public void endNested(RequestPredicate predicate) {
+		attributes = nestedAttributes.removeFirst();
 	}
 
 	@Override
 	public void route(RequestPredicate predicate, HandlerFunction<?> handlerFunction) {
-		assertThat(this.attributes).isNotNull();
+		Stream<Map<String, Object>> current = Optional.ofNullable(attributes).stream();
-		this.attributes = null;
+		Stream<Map<String, Object>> nested = nestedAttributes.stream().filter(Objects::nonNull);
+		routerFunctionsAttributes.add(Stream.concat(current, nested).collect(Collectors.toUnmodifiableList()));
+		attributes = null;
 	}
 
 	@Override
@@ -61,7 +78,6 @@ class AttributesTestVisitor implements RouterFunctions.Visitor {
 
 	@Override
 	public void attributes(Map<String, Object> attributes) {
-		assertThat(attributes).containsExactly(entry("foo", "bar"), entry("baz", "qux"));
 		this.attributes = attributes;
 		this.visitCount++;
 	}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -18,6 +18,8 @@ package org.springframework.web.reactive.function.server;
 
 import java.io.IOException;
 import java.util.Collections;
+import java.util.List;
+import java.util.Map;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.junit.jupiter.api.Test;
@@ -236,12 +238,28 @@ public class RouterFunctionBuilderTests {
 					atts.put("foo", "bar");
 					atts.put("baz", "qux");
 				})
+				.path("/atts", b1 -> b1
+					.GET("/3", request -> ServerResponse.ok().build())
+					.withAttribute("foo", "bar")
+					.GET("/4", request -> ServerResponse.ok().build())
+					.withAttribute("baz", "qux")
+					.path("/5", b2 -> b2
+						.GET(request -> ServerResponse.ok().build())
+						.withAttribute("foo", "n3"))
+					.withAttribute("foo", "n2")
+				)
+				.withAttribute("foo", "n1")
 				.build();
 
 		AttributesTestVisitor visitor = new AttributesTestVisitor();
 		route.accept(visitor);
-		assertThat(visitor.visitCount()).isEqualTo(2);
+		assertThat(visitor.routerFunctionsAttributes()).containsExactly(
+				List.of(Map.of("foo", "bar", "baz", "qux")),
+				List.of(Map.of("foo", "bar", "baz", "qux")),
+				List.of(Map.of("foo", "bar"), Map.of("foo", "n1")),
+				List.of(Map.of("baz", "qux"), Map.of("foo", "n1")),
+				List.of(Map.of("foo", "n3"), Map.of("foo", "n2"), Map.of("foo", "n1"))
+		);
+		assertThat(visitor.visitCount()).isEqualTo(7);
 	}
-
-
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -17,6 +17,8 @@
 package org.springframework.web.reactive.function.server;
 
 import java.util.Collections;
+import java.util.List;
+import java.util.Map;
 
 import org.junit.jupiter.api.Test;
 import reactor.core.publisher.Mono;
@@ -26,7 +28,10 @@ import org.springframework.web.testfixture.http.server.reactive.MockServerHttpRe
 import org.springframework.web.testfixture.server.MockServerWebExchange;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.http.HttpMethod.GET;
 import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
+import static org.springframework.web.reactive.function.server.RequestPredicates.method;
+import static org.springframework.web.reactive.function.server.RequestPredicates.path;
 
 /**
  * @author Arjen Poutsma
@@ -137,11 +142,28 @@ public class RouterFunctionTests {
 				.withAttributes(atts -> {
 					atts.put("foo", "bar");
 					atts.put("baz", "qux");
-				}));
+				}))
+				.and(RouterFunctions.nest(path("/atts"),
+						RouterFunctions.route(GET("/3"), request -> ServerResponse.ok().build())
+						.withAttribute("foo", "bar")
+						.and(RouterFunctions.route(GET("/4"), request -> ServerResponse.ok().build())
+						.withAttribute("baz", "qux"))
+						.and(RouterFunctions.nest(path("/5"),
+								RouterFunctions.route(method(GET), request -> ServerResponse.ok().build())
+								.withAttribute("foo", "n3"))
+						.withAttribute("foo", "n2")))
+				.withAttribute("foo", "n1"));
 
 		AttributesTestVisitor visitor = new AttributesTestVisitor();
 		route.accept(visitor);
-		assertThat(visitor.visitCount()).isEqualTo(2);
+		assertThat(visitor.routerFunctionsAttributes()).containsExactly(
+				List.of(Map.of("foo", "bar", "baz", "qux")),
+				List.of(Map.of("foo", "bar", "baz", "qux")),
+				List.of(Map.of("foo", "bar"), Map.of("foo", "n1")),
+				List.of(Map.of("baz", "qux"), Map.of("foo", "n1")),
+				List.of(Map.of("foo", "n3"), Map.of("foo", "n2"), Map.of("foo", "n1"))
+		);
+		assertThat(visitor.visitCount()).isEqualTo(7);
 	}
 
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.web.reactive.function.server
 
+import org.assertj.core.api.Assertions.assertThat
 import org.assertj.core.api.Assertions.assertThatExceptionOfType
 import org.junit.jupiter.api.Test
 import org.springframework.core.io.ClassPathResource
@@ -25,6 +26,7 @@ import org.springframework.http.HttpStatus
 import org.springframework.http.MediaType.*
 import org.springframework.web.testfixture.http.server.reactive.MockServerHttpRequest.*
 import org.springframework.web.testfixture.server.MockServerWebExchange
+import org.springframework.web.reactive.function.server.AttributesTestVisitor
 import reactor.test.StepVerifier
 
 /**
@@ -163,6 +165,20 @@ class CoRouterFunctionDslTests {
 			.verifyComplete()
 	}
 
+	@Test
+	fun attributes() {
+		val visitor = AttributesTestVisitor()
+		attributesRouter.accept(visitor)
+		assertThat(visitor.routerFunctionsAttributes()).containsExactly(
+			listOf(mapOf("foo" to "bar", "baz" to "qux")),
+			listOf(mapOf("foo" to "bar", "baz" to "qux")),
+			listOf(mapOf("foo" to "bar"), mapOf("foo" to "n1")),
+			listOf(mapOf("baz" to "qux"), mapOf("foo" to "n1")),
+			listOf(mapOf("foo" to "n3"), mapOf("foo" to "n2"), mapOf("foo" to "n1"))
+		);
+		assertThat(visitor.visitCount()).isEqualTo(7);
+	}
+
 	private fun sampleRouter() = coRouter {
 		(GET("/foo/") or GET("/foos/")) { req -> handle(req) }
 		"/api".nest {
@@ -231,6 +247,39 @@ class CoRouterFunctionDslTests {
 		}
 	}
 
+	private val attributesRouter = router {
+		GET("/atts/1") {
+			ok().build()
+		}
+		withAttribute("foo", "bar")
+		withAttribute("baz", "qux")
+		GET("/atts/2") {
+			ok().build()
+		}
+		withAttributes { atts ->
+			atts["foo"] = "bar"
+			atts["baz"] = "qux"
+		}
+		"/atts".nest {
+			GET("/3") {
+				ok().build()
+			}
+			withAttribute("foo", "bar")
+			GET("/4") {
+				ok().build()
+			}
+			withAttribute("baz", "qux")
+			"/5".nest {
+				GET {
+					ok().build()
+				}
+				withAttribute("foo", "n3")
+			}
+			withAttribute("foo", "n2")
+		}
+		withAttribute("foo", "n1")
+	}
+
 	@Suppress("UNUSED_PARAMETER")
 	private suspend fun handleFromClass(req: ServerRequest) = ServerResponse.ok().buildAndAwait()
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.web.reactive.function.server
 
+import org.assertj.core.api.Assertions.assertThat
 import org.assertj.core.api.Assertions.assertThatExceptionOfType
 import org.junit.jupiter.api.Test
 import org.springframework.core.io.ClassPathResource
@@ -25,6 +26,7 @@ import org.springframework.http.HttpStatus
 import org.springframework.http.MediaType.*
 import org.springframework.web.testfixture.http.server.reactive.MockServerHttpRequest.*
 import org.springframework.web.testfixture.server.MockServerWebExchange
+import org.springframework.web.reactive.function.server.AttributesTestVisitor
 import reactor.core.publisher.Mono
 import reactor.test.StepVerifier
 
@@ -153,6 +155,19 @@ class RouterFunctionDslTests {
 		}
 	}
 
+	@Test
+	fun attributes() {
+		val visitor = AttributesTestVisitor()
+		attributesRouter.accept(visitor)
+		assertThat(visitor.routerFunctionsAttributes()).containsExactly(
+			listOf(mapOf("foo" to "bar", "baz" to "qux")),
+			listOf(mapOf("foo" to "bar", "baz" to "qux")),
+			listOf(mapOf("foo" to "bar"), mapOf("foo" to "n1")),
+			listOf(mapOf("baz" to "qux"), mapOf("foo" to "n1")),
+			listOf(mapOf("foo" to "n3"), mapOf("foo" to "n2"), mapOf("foo" to "n1"))
+		);
+		assertThat(visitor.visitCount()).isEqualTo(7);
+	}
 
 	private fun sampleRouter() = router {
 		(GET("/foo/") or GET("/foos/")) { req -> handle(req) }
@@ -210,6 +225,39 @@ class RouterFunctionDslTests {
 		}
 	}
 
+	private val attributesRouter = router {
+		GET("/atts/1") {
+			ok().build()
+		}
+		withAttribute("foo", "bar")
+		withAttribute("baz", "qux")
+		GET("/atts/2") {
+			ok().build()
+		}
+		withAttributes { atts ->
+			atts["foo"] = "bar"
+			atts["baz"] = "qux"
+		}
+		"/atts".nest {
+			GET("/3") {
+				ok().build()
+			}
+			withAttribute("foo", "bar")
+			GET("/4") {
+				ok().build()
+			}
+			withAttribute("baz", "qux")
+			"/5".nest {
+				GET {
+					ok().build()
+				}
+				withAttribute("foo", "n3")
+			}
+			withAttribute("foo", "n2")
+		}
+		withAttribute("foo", "n1")
+	}
+
 	@Suppress("UNUSED_PARAMETER")
 	private fun handleFromClass(req: ServerRequest) = ServerResponse.ok().build()
 }

spring-webmvc/src/main/kotlin/org/springframework/web/servlet/function/RouterFunctionDsl.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -21,7 +21,7 @@ import org.springframework.http.HttpMethod
 import org.springframework.http.HttpStatusCode
 import org.springframework.http.MediaType
 import java.net.URI
-import java.util.*
+import java.util.Optional
 import java.util.function.Supplier
 
 /**
@@ -699,6 +699,30 @@ class RouterFunctionDsl internal constructor (private val init: (RouterFunctionD
 		builder.onError({it is E}, responseProvider)
 	}
 
+	/**
+	 * Add an attribute with the given name and value to the last route built with this builder.
+	 * @param name the attribute name
+	 * @param value the attribute value
+	 * @since 6.0
+	 */
+	fun withAttribute(name: String, value: Any) {
+		builder.withAttribute(name, value)
+	}
+
+	/**
+	 * Manipulate the attributes of the last route built with the given consumer.
+	 *
+	 * The map provided to the consumer is "live", so that the consumer can be used
+	 * to [overwrite][MutableMap.put] existing attributes,
+	 * [remove][MutableMap.remove] attributes, or use any of the other
+	 * [MutableMap] methods.
+	 * @param attributesConsumer a function that consumes the attributes map
+	 * @since 6.0
+	 */
+	fun withAttributes(attributesConsumer: (MutableMap<String, Any>) -> Unit) {
+		builder.withAttributes(attributesConsumer)
+	}
+
 	/**
 	 * Return a composed routing function created from all the registered routes.
 	 */

spring-webmvc/src/test/java/org/springframework/web/servlet/function/AttributesTestVisitor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -16,42 +16,58 @@
 
 package org.springframework.web.servlet.function;
 
+import java.util.Deque;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
 
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.entry;
-
 /**
  * @author Arjen Poutsma
  */
 class AttributesTestVisitor implements RouterFunctions.Visitor {
 
+	private Deque<Map<String, Object>> nestedAttributes = new LinkedList<>();
+
 	@Nullable
 	private Map<String, Object> attributes;
 
+	private List<List<Map<String, Object>>> routerFunctionsAttributes = new LinkedList<>();
+
 	private int visitCount;
 
+	public List<List<Map<String, Object>>> routerFunctionsAttributes() {
+		return this.routerFunctionsAttributes;
+	}
+
 	public int visitCount() {
 		return this.visitCount;
 	}
 
 	@Override
 	public void startNested(RequestPredicate predicate) {
+		nestedAttributes.addFirst(attributes);
+		attributes = null;
 	}
 
 	@Override
 	public void endNested(RequestPredicate predicate) {
+		attributes = nestedAttributes.removeFirst();
 	}
 
 	@Override
 	public void route(RequestPredicate predicate, HandlerFunction<?> handlerFunction) {
-		assertThat(this.attributes).isNotNull();
+		Stream<Map<String, Object>> current = Optional.ofNullable(attributes).stream();
-		this.attributes = null;
+		Stream<Map<String, Object>> nested = nestedAttributes.stream().filter(Objects::nonNull);
+		routerFunctionsAttributes.add(Stream.concat(current, nested).collect(Collectors.toUnmodifiableList()));
+		attributes = null;
 	}
 
 	@Override
@@ -60,7 +76,6 @@ class AttributesTestVisitor implements RouterFunctions.Visitor {
 
 	@Override
 	public void attributes(Map<String, Object> attributes) {
-		assertThat(attributes).containsExactly(entry("foo", "bar"), entry("baz", "qux"));
 		this.attributes = attributes;
 		this.visitCount++;
 	}

spring-webmvc/src/test/java/org/springframework/web/servlet/function/RouterFunctionBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -17,6 +17,8 @@
 package org.springframework.web.servlet.function;
 
 import java.io.IOException;
+import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
@@ -226,12 +228,28 @@ class RouterFunctionBuilderTests {
 					atts.put("foo", "bar");
 					atts.put("baz", "qux");
 				})
+				.path("/atts", b1 -> b1
+						.GET("/3", request -> ServerResponse.ok().build())
+						.withAttribute("foo", "bar")
+						.GET("/4", request -> ServerResponse.ok().build())
+						.withAttribute("baz", "qux")
+						.path("/5", b2 -> b2
+							.GET(request -> ServerResponse.ok().build())
+							.withAttribute("foo", "n3"))
+						.withAttribute("foo", "n2")
+					)
+					.withAttribute("foo", "n1")
 				.build();
 
 		AttributesTestVisitor visitor = new AttributesTestVisitor();
 		route.accept(visitor);
-		assertThat(visitor.visitCount()).isEqualTo(2);
+		assertThat(visitor.routerFunctionsAttributes()).containsExactly(
+				List.of(Map.of("foo", "bar", "baz", "qux")),
+				List.of(Map.of("foo", "bar", "baz", "qux")),
+				List.of(Map.of("foo", "bar"), Map.of("foo", "n1")),
+				List.of(Map.of("baz", "qux"), Map.of("foo", "n1")),
+				List.of(Map.of("foo", "n3"), Map.of("foo", "n2"), Map.of("foo", "n1"))
+		);
+		assertThat(visitor.visitCount()).isEqualTo(7);
 	}
-
-
 }

spring-webmvc/src/test/java/org/springframework/web/servlet/function/RouterFunctionTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -17,6 +17,8 @@
 package org.springframework.web.servlet.function;
 
 import java.util.Collections;
+import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 
 import org.junit.jupiter.api.Test;
@@ -24,7 +26,10 @@ import org.junit.jupiter.api.Test;
 import org.springframework.web.servlet.handler.PathPatternsTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.http.HttpMethod.GET;
 import static org.springframework.web.servlet.function.RequestPredicates.GET;
+import static org.springframework.web.servlet.function.RequestPredicates.method;
+import static org.springframework.web.servlet.function.RequestPredicates.path;
 
 /**
  * @author Arjen Poutsma
@@ -120,11 +125,28 @@ class RouterFunctionTests {
 				.withAttributes(atts -> {
 					atts.put("foo", "bar");
 					atts.put("baz", "qux");
-				}));
+				}))
+				.and(RouterFunctions.nest(path("/atts"),
+						RouterFunctions.route(GET("/3"), request -> ServerResponse.ok().build())
+						.withAttribute("foo", "bar")
+						.and(RouterFunctions.route(GET("/4"), request -> ServerResponse.ok().build())
+						.withAttribute("baz", "qux"))
+						.and(RouterFunctions.nest(path("/5"),
+								RouterFunctions.route(method(GET), request -> ServerResponse.ok().build())
+								.withAttribute("foo", "n3"))
+						.withAttribute("foo", "n2")))
+				.withAttribute("foo", "n1"));
 
 		AttributesTestVisitor visitor = new AttributesTestVisitor();
 		route.accept(visitor);
-		assertThat(visitor.visitCount()).isEqualTo(2);
+		assertThat(visitor.routerFunctionsAttributes()).containsExactly(
+				List.of(Map.of("foo", "bar", "baz", "qux")),
+				List.of(Map.of("foo", "bar", "baz", "qux")),
+				List.of(Map.of("foo", "bar"), Map.of("foo", "n1")),
+				List.of(Map.of("baz", "qux"), Map.of("foo", "n1")),
+				List.of(Map.of("foo", "n3"), Map.of("foo", "n2"), Map.of("foo", "n1"))
+		);
+		assertThat(visitor.visitCount()).isEqualTo(7);
 	}
 
 

spring-webmvc/src/test/kotlin/org/springframework/web/servlet/function/RouterFunctionDslTests.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -134,6 +134,20 @@ class RouterFunctionDslTests {
 		assertThat(sampleRouter().route(request).get().handle(request).headers().getFirst("foo")).isEqualTo("bar")
 	}
 
+	@Test
+	fun attributes() {
+		val visitor = AttributesTestVisitor()
+		attributesRouter.accept(visitor)
+		assertThat(visitor.routerFunctionsAttributes()).containsExactly(
+			listOf(mapOf("foo" to "bar", "baz" to "qux")),
+			listOf(mapOf("foo" to "bar", "baz" to "qux")),
+			listOf(mapOf("foo" to "bar"), mapOf("foo" to "n1")),
+			listOf(mapOf("baz" to "qux"), mapOf("foo" to "n1")),
+			listOf(mapOf("foo" to "n3"), mapOf("foo" to "n2"), mapOf("foo" to "n1"))
+		);
+		assertThat(visitor.visitCount()).isEqualTo(7);
+	}
+
 	private fun sampleRouter() = router {
 		(GET("/foo/") or GET("/foos/")) { req -> handle(req) }
 		"/api".nest {
@@ -202,6 +216,39 @@ class RouterFunctionDslTests {
 		}
 	}
 
+	private val attributesRouter = router {
+		GET("/atts/1") {
+			ok().build()
+		}
+		withAttribute("foo", "bar")
+		withAttribute("baz", "qux")
+		GET("/atts/2") {
+			ok().build()
+		}
+		withAttributes { atts ->
+			atts["foo"] = "bar"
+			atts["baz"] = "qux"
+		}
+		"/atts".nest {
+			GET("/3") {
+				ok().build()
+			}
+			withAttribute("foo", "bar")
+			GET("/4") {
+				ok().build()
+			}
+			withAttribute("baz", "qux")
+			"/5".nest {
+				GET {
+					ok().build()
+				}
+				withAttribute("foo", "n3")
+			}
+			withAttribute("foo", "n2")
+		}
+		withAttribute("foo", "n1")
+	}
+
 	@Suppress("UNUSED_PARAMETER")
 	private fun handleFromClass(req: ServerRequest) = ServerResponse.ok().build()
 }