Merge pull request #17701 from sdeleuze

* pr/17701:
  Polish "Add WebFlux Coroutines smoke test"
  Polish "Add dependency management for Kotlin Coroutines"
  Add WebFlux Coroutines smoke test
  Add dependency management for Kotlin Coroutines

Closes gh-17701

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -139,6 +139,7 @@
 		<junit-jupiter.version>5.5.1</junit-jupiter.version>
 		<kafka.version>2.3.0</kafka.version>
 		<kotlin.version>1.3.41</kotlin.version>
+		<kotlin-coroutines.version>1.3.0-RC</kotlin-coroutines.version>
 		<lettuce.version>5.1.8.RELEASE</lettuce.version>
 		<liquibase.version>3.7.0</liquibase.version>
 		<log4j2.version>2.12.0</log4j2.version>
@@ -2595,6 +2596,13 @@
 				<scope>import</scope>
 				<type>pom</type>
 			</dependency>
+			<dependency>
+				<groupId>org.jetbrains.kotlinx</groupId>
+				<artifactId>kotlinx-coroutines-bom</artifactId>
+				<version>${kotlin-coroutines.version}</version>
+				<scope>import</scope>
+				<type>pom</type>
+			</dependency>
 			<dependency>
 				<groupId>org.jolokia</groupId>
 				<artifactId>jolokia-core</artifactId>

spring-boot-tests/spring-boot-smoke-tests/pom.xml

@@ -98,6 +98,7 @@
 		<module>spring-boot-smoke-test-web-static</module>
 		<module>spring-boot-smoke-test-web-ui</module>
 		<module>spring-boot-smoke-test-webflux</module>
+		<module>spring-boot-smoke-test-webflux-coroutines</module>
 		<module>spring-boot-smoke-test-websocket-jetty</module>
 		<module>spring-boot-smoke-test-websocket-tomcat</module>
 		<module>spring-boot-smoke-test-websocket-undertow</module>

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-webflux-coroutines/pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<!-- Your own application should inherit from spring-boot-starter-parent -->
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-smoke-tests</artifactId>
+		<version>${revision}</version>
+	</parent>
+	<artifactId>spring-boot-smoke-test-webflux-coroutines</artifactId>
+	<name>Spring Boot WebFlux Coroutines Smoke Test</name>
+	<description>Spring Boot WebFlux Coroutines Smoke Test</description>
+	<properties>
+		<main.basedir>${basedir}/../../..</main.basedir>
+		<m2eclipse.wtp.contextRoot>/</m2eclipse.wtp.contextRoot>
+	</properties>
+	<dependencies>
+		<!-- Compile -->
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-webflux</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.jetbrains.kotlin</groupId>
+			<artifactId>kotlin-reflect</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.jetbrains.kotlin</groupId>
+			<artifactId>kotlin-stdlib-jdk8</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.jetbrains.kotlinx</groupId>
+			<artifactId>kotlinx-coroutines-reactor</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>com.fasterxml.jackson.module</groupId>
+			<artifactId>jackson-module-kotlin</artifactId>
+		</dependency>
+		<!-- Test -->
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
+		<testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+			<plugin>
+				<groupId>org.jetbrains.kotlin</groupId>
+				<artifactId>kotlin-maven-plugin</artifactId>
+				<configuration>
+					<args>
+						<arg>-Xjsr305=strict</arg>
+					</args>
+					<compilerPlugins>
+						<plugin>spring</plugin>
+					</compilerPlugins>
+				</configuration>
+				<dependencies>
+					<dependency>
+						<groupId>org.jetbrains.kotlin</groupId>
+						<artifactId>kotlin-maven-allopen</artifactId>
+						<version>${kotlin.version}</version>
+					</dependency>
+				</dependencies>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-webflux-coroutines/src/main/kotlin/smoketest/coroutines/CoroutinesController.kt

+package smoketest.coroutines
+
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.flow
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+class CoroutinesController {
+
+	@GetMapping("/suspending")
+	suspend fun suspendingFunction(): String {
+		delay(10)
+		return "Hello World"
+	}
+
+	@GetMapping("/flow")
+	fun flow() = flow {
+		delay(10)
+		emit("Hello ")
+		delay(10)
+		emit("World")
+	}
+
+}

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-webflux-coroutines/src/main/kotlin/smoketest/coroutines/SampleCoroutinesApplication.kt

+package smoketest.coroutines
+
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.runApplication
+
+@SpringBootApplication
+class SampleCoroutinesApplication
+fun main(args: Array<String>) {
+	runApplication<SampleCoroutinesApplication>(*args)
+
+}

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-webflux-coroutines/src/test/kotlin/smoketest/coroutines/CoroutinesControllerTests.kt

+package smoketest.coroutines
+
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.boot.test.context.SpringBootTest.*
+import org.springframework.http.MediaType
+import org.springframework.test.web.reactive.server.WebTestClient
+import org.springframework.test.web.reactive.server.expectBody
+
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+class CoroutinesControllerTests(@Autowired private val webClient: WebTestClient) {
+
+	@Test
+	fun testSuspendingFunction() {
+		webClient.get().uri("/suspending").accept(MediaType.TEXT_PLAIN).exchange()
+				.expectBody<String>().isEqualTo("Hello World")
+	}
+
+	@Test
+	fun testFlow() {
+		webClient.get().uri("/flow").accept(MediaType.TEXT_PLAIN).exchange()
+				.expectBody<String>().isEqualTo("Hello World")
+	}
+
+}