Add minimal Kotlin DSL RouterFunction attributes support

Closes gh-28567

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 5.3
+	 */
+	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][Map.put] existing attributes,
+	 * [remove][Map.remove] attributes, or use any of the other
+	 * [Map] methods.
+	 * @param attributesConsumer a function that consumes the attributes map
+	 * @since 5.3
+	 */
+	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 5.3
+	 */
+	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][Map.put] existing attributes,
+	 * [remove][Map.remove] attributes, or use any of the other
+	 * [Map] methods.
+	 * @param attributesConsumer a function that consumes the attributes map
+	 * @since 5.3
+	 */
+	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/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.
@@ -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 5.3
+	 */
+	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][Map.put] existing attributes,
+	 * [remove][Map.remove] attributes, or use any of the other
+	 * [Map] methods.
+	 * @param attributesConsumer a function that consumes the attributes map
+	 * @since 5.3
+	 */
+	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/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()
 }