Add ServerRequest.bindAndAwait Kotlin extension

Closes spring-projectsgh-36092

Author: sdeleuze

framework-docs/src/main/kotlin/org/springframework/docs/web/webfluxfnrequest/RequestHandler.kt

@@ -17,13 +17,13 @@
 package org.springframework.docs.web.webfluxfnrequest
 
 import org.springframework.web.reactive.function.server.ServerRequest
-import reactor.core.publisher.Mono
+import org.springframework.web.reactive.function.server.bindAndAwait
 
 class RequestHandler {
 
-	fun bind(request: ServerRequest) {
+	suspend fun bind(request: ServerRequest) {
 		// tag::snippet[]
-		val pet: Mono<Pet> = request.bind(Pet::class.java) { dataBinder -> dataBinder.setAllowedFields("name") }
+		val pet: Pet? = request.bindAndAwait<Pet>{ dataBinder -> dataBinder.setAllowedFields("name") }
 		// end::snippet[]
 	}
 

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

@@ -24,6 +24,7 @@ import org.springframework.core.ParameterizedTypeReference
 import org.springframework.http.MediaType
 import org.springframework.http.codec.multipart.Part
 import org.springframework.util.MultiValueMap
+import org.springframework.web.bind.WebDataBinder
 import org.springframework.web.server.WebSession
 import reactor.core.publisher.Flux
 import reactor.core.publisher.Mono
@@ -202,3 +203,23 @@ fun ServerRequest.Headers.contentTypeOrNull(): MediaType? =
 fun ServerRequest.pathVariableOrNull(name: String): String? {
 	return pathVariables()[name]
 }
+
+/**
+ * Extension for [ServerRequest.bind] providing a `bindAndAwait<Foo>()` Coroutines
+ * variant leveraging Kotlin reified type parameters.
+ *
+ * @author Sebastien Deleuze
+ * @since 7.0.3
+ */
+suspend inline fun <reified T : Any> ServerRequest.bindAndAwait(): T? =
+	bind(T::class.java).awaitSingleOrNull()
+
+/**
+ * Extension for [ServerRequest.bind] providing a `bindAndAwait<Foo> { ... }` Coroutines
+ * variant leveraging Kotlin reified type parameters.
+ *
+ * @author Sebastien Deleuze
+ * @since 7.0.3
+ */
+suspend inline fun <reified T : Any> ServerRequest.bindAndAwait(noinline dataBinderCustomizer: (WebDataBinder) -> Unit): T? =
+	bind(T::class.java, dataBinderCustomizer).awaitSingleOrNull()

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

@@ -229,5 +229,35 @@ class ServerRequestExtensionsTests {
 		verify { request.pathVariables() }
 	}
 
+	@Test
+	suspend fun `bindAndAwait non-null`() {
+		val foo = Foo()
+		every { request.bind(Foo::class.java) } returns Mono.just(foo)
+		assertThat(request.bindAndAwait<Foo>()).isEqualTo(foo)
+		verify { request.bind(Foo::class.java) }
+	}
+
+	@Test
+	suspend fun `bindAndAwait null`() {
+		every { request.bind(Foo::class.java) } returns Mono.empty()
+		assertThat(request.bindAndAwait<Foo>()).isNull()
+		verify { request.bind(Foo::class.java) }
+	}
+
+	@Test
+	suspend fun `bindAndAwait non-null with customize`() {
+		val foo = Foo()
+		every { request.bind(Foo::class.java, any()) } returns Mono.just(foo)
+		assertThat(request.bindAndAwait<Foo> { it.setAllowedFields("name") }).isEqualTo(foo)
+		verify { request.bind(Foo::class.java, any()) }
+	}
+
+	@Test
+	suspend fun `bindAndAwait null with customize`() {
+		every { request.bind(Foo::class.java, any()) } returns Mono.empty()
+		assertThat(request.bindAndAwait<Foo> { it.setAllowedFields("name") }).isNull()
+		verify { request.bind(Foo::class.java, any()) }
+	}
+
 	class Foo
 }