Upgrade to Coroutines 1.4.0-M1 and use awaitSingle()

This commit raises the minimum Coroutines version supported
to 1.4.0-M1 and above, and changes usages of awaitFirst() or
awaitFirstOrNull() to awaitSingle() or awaitSingleOrNull()
to fix gh-25007.

Closes gh-25914
Closes gh-25007

build.gradle

@@ -32,7 +32,7 @@ configure(allprojects) { project ->
 			mavenBom "io.rsocket:rsocket-bom:1.1.0-RC1"
 			mavenBom "org.eclipse.jetty:jetty-bom:9.4.32.v20200930"
 			mavenBom "org.jetbrains.kotlin:kotlin-bom:1.4.10"
-			mavenBom "org.jetbrains.kotlinx:kotlinx-coroutines-bom:1.3.9"
+			mavenBom "org.jetbrains.kotlinx:kotlinx-coroutines-bom:1.4.0-M1"
 			mavenBom "org.junit:junit-bom:5.7.0"
 		}
 		dependencies {

spring-core/kotlin-coroutines/src/main/kotlin/org/springframework/core/CoroutinesUtils.kt

@@ -22,7 +22,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.async
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.reactive.awaitFirstOrNull
+import kotlinx.coroutines.reactive.awaitSingleOrNull
 import kotlinx.coroutines.reactor.asFlux
 
 import kotlinx.coroutines.reactor.mono
@@ -49,7 +49,7 @@ internal fun <T: Any> deferredToMono(source: Deferred<T>) =
  * @since 5.2
  */
 internal fun <T: Any> monoToDeferred(source: Mono<T>) =
-		GlobalScope.async(Dispatchers.Unconfined) { source.awaitFirstOrNull() }
+		GlobalScope.async(Dispatchers.Unconfined) { source.awaitSingleOrNull() }
 
 /**
  * Invoke a suspending function and converts it to [Mono] or [reactor.core.publisher.Flux].

spring-messaging/src/main/kotlin/org/springframework/messaging/rsocket/RSocketRequesterExtensions.kt

@@ -19,7 +19,7 @@ package org.springframework.messaging.rsocket
 import io.rsocket.transport.ClientTransport
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.reactive.asFlow
-import kotlinx.coroutines.reactive.awaitFirstOrNull
+import kotlinx.coroutines.reactive.awaitSingleOrNull
 import kotlinx.coroutines.reactive.awaitSingle
 import org.reactivestreams.Publisher
 import org.springframework.core.ParameterizedTypeReference
@@ -103,7 +103,7 @@ inline fun <reified T : Any> RSocketRequester.RequestSpec.dataWithType(flow: Flo
  * @since 5.2
  */
 suspend fun RSocketRequester.RetrieveSpec.sendAndAwait() {
-	send().awaitFirstOrNull()
+	send().awaitSingleOrNull()
 }
 
 /**
@@ -122,7 +122,7 @@ suspend inline fun <reified T : Any> RSocketRequester.RetrieveSpec.retrieveAndAw
  * @since 5.2.1
  */
 suspend inline fun <reified T : Any> RSocketRequester.RetrieveSpec.retrieveAndAwaitOrNull(): T? =
-		retrieveMono(object : ParameterizedTypeReference<T>() {}).awaitFirstOrNull()
+		retrieveMono(object : ParameterizedTypeReference<T>() {}).awaitSingleOrNull()
 
 /**
  * Coroutines variant of [RSocketRequester.RetrieveSpec.retrieveFlux].

spring-r2dbc/src/main/kotlin/org/springframework/r2dbc/core/DatabaseClientExtensions.kt

@@ -16,15 +16,15 @@
 
 package org.springframework.r2dbc.core
 
-import kotlinx.coroutines.reactive.awaitFirstOrNull
+import kotlinx.coroutines.reactive.awaitSingleOrNull
 
 /**
  * Coroutines variant of [DatabaseClient.GenericExecuteSpec.then].
  *
  * @author Sebastien Deleuze
  */
 suspend fun DatabaseClient.GenericExecuteSpec.await() {
-	then().awaitFirstOrNull()
+	then().awaitSingleOrNull()
 }
 
 /**

spring-r2dbc/src/main/kotlin/org/springframework/r2dbc/core/RowsFetchSpecExtensions.kt

@@ -17,7 +17,7 @@ package org.springframework.r2dbc.core
 
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.reactive.asFlow
-import kotlinx.coroutines.reactive.awaitFirstOrNull
+import kotlinx.coroutines.reactive.awaitSingleOrNull
 import org.springframework.dao.EmptyResultDataAccessException
 
 /**
@@ -26,7 +26,7 @@ import org.springframework.dao.EmptyResultDataAccessException
  * @author Sebastien Deleuze
  */
 suspend fun <T> RowsFetchSpec<T>.awaitOne(): T {
-	return one().awaitFirstOrNull() ?: throw EmptyResultDataAccessException(1)
+	return one().awaitSingleOrNull() ?: throw EmptyResultDataAccessException(1)
 }
 
 /**
@@ -35,24 +35,24 @@ suspend fun <T> RowsFetchSpec<T>.awaitOne(): T {
  * @author Sebastien Deleuze
  */
 suspend fun <T> RowsFetchSpec<T>.awaitOneOrNull(): T? =
-		one().awaitFirstOrNull()
+		one().awaitSingleOrNull()
 
 /**
  * Non-nullable Coroutines variant of [RowsFetchSpec.first].
  *
  * @author Sebastien Deleuze
  */
-suspend fun <T> RowsFetchSpec<T>.awaitFirst(): T {
-	return first().awaitFirstOrNull() ?: throw EmptyResultDataAccessException(1)
+suspend fun <T> RowsFetchSpec<T>.awaitSingle(): T {
+	return first().awaitSingleOrNull() ?: throw EmptyResultDataAccessException(1)
 }
 
 /**
  * Nullable Coroutines variant of [RowsFetchSpec.first].
  *
  * @author Sebastien Deleuze
  */
-suspend fun <T> RowsFetchSpec<T>.awaitFirstOrNull(): T? =
-		first().awaitFirstOrNull()
+suspend fun <T> RowsFetchSpec<T>.awaitSingleOrNull(): T? =
+		first().awaitSingleOrNull()
 
 /**
  * Coroutines [Flow] variant of [RowsFetchSpec.all].

spring-r2dbc/src/test/kotlin/org/springframework/r2dbc/core/RowsFetchSpecExtensionsTests.kt

@@ -98,7 +98,7 @@ class RowsFetchSpecExtensionsTests {
 		every { spec.first() } returns Mono.just("foo")
 
 		runBlocking {
-			assertThat(spec.awaitFirst()).isEqualTo("foo")
+			assertThat(spec.awaitSingle()).isEqualTo("foo")
 		}
 
 		verify {
@@ -112,7 +112,7 @@ class RowsFetchSpecExtensionsTests {
 		every { spec.first() } returns Mono.empty()
 
 		assertThatExceptionOfType(EmptyResultDataAccessException::class.java).isThrownBy {
-			runBlocking { spec.awaitFirst() }
+			runBlocking { spec.awaitSingle() }
 		}
 
 		verify {
@@ -121,12 +121,12 @@ class RowsFetchSpecExtensionsTests {
 	}
 
 	@Test
-	fun awaitFirstOrNullWithValue() {
+	fun awaitSingleOrNullWithValue() {
 		val spec = mockk<RowsFetchSpec<String>>()
 		every { spec.first() } returns Mono.just("foo")
 
 		runBlocking {
-			assertThat(spec.awaitFirstOrNull()).isEqualTo("foo")
+			assertThat(spec.awaitSingleOrNull()).isEqualTo("foo")
 		}
 
 		verify {
@@ -135,12 +135,12 @@ class RowsFetchSpecExtensionsTests {
 	}
 
 	@Test
-	fun awaitFirstOrNullWithNull() {
+	fun awaitSingleOrNullWithNull() {
 		val spec = mockk<RowsFetchSpec<String>>()
 		every { spec.first() } returns Mono.empty()
 
 		runBlocking {
-			assertThat(spec.awaitFirstOrNull()).isNull()
+			assertThat(spec.awaitSingleOrNull()).isNull()
 		}
 
 		verify {

spring-webflux/src/main/kotlin/org/springframework/web/reactive/function/client/ClientResponseExtensions.kt

@@ -17,7 +17,7 @@
 package org.springframework.web.reactive.function.client
 
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.reactive.awaitFirstOrNull
+import kotlinx.coroutines.reactive.awaitSingleOrNull
 import kotlinx.coroutines.reactive.awaitSingle
 import kotlinx.coroutines.reactive.asFlow
 import org.springframework.core.ParameterizedTypeReference
@@ -115,7 +115,7 @@ suspend fun <T : Any> ClientResponse.awaitBody(clazz: KClass<T>): T =
  * @since 5.2
  */
 suspend inline fun <reified T : Any> ClientResponse.awaitBodyOrNull(): T? =
-		bodyToMono<T>().awaitFirstOrNull()
+		bodyToMono<T>().awaitSingleOrNull()
 
 /**
  * `KClass` nullable coroutines variant of [ClientResponse.bodyToMono].
@@ -125,7 +125,7 @@ suspend inline fun <reified T : Any> ClientResponse.awaitBodyOrNull(): T? =
  * @since 5.3
  */
 suspend fun <T : Any> ClientResponse.awaitBodyOrNull(clazz: KClass<T>): T? =
-		bodyToMono(clazz.java).awaitFirstOrNull()
+		bodyToMono(clazz.java).awaitSingleOrNull()
 
 /**
  * Coroutines variant of [ClientResponse.toEntity].

spring-webflux/src/main/kotlin/org/springframework/web/reactive/function/client/WebClientExtensions.kt

@@ -19,7 +19,7 @@ package org.springframework.web.reactive.function.client
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.reactive.asFlow
-import kotlinx.coroutines.reactive.awaitFirst
+import kotlinx.coroutines.reactive.awaitSingle
 import kotlinx.coroutines.reactive.awaitSingle
 import kotlinx.coroutines.reactor.asFlux
 import kotlinx.coroutines.reactor.mono
@@ -87,7 +87,7 @@ suspend fun RequestHeadersSpec<out RequestHeadersSpec<*>>.awaitExchange(): Clien
  * @since 5.3
  */
 suspend fun <T: Any> RequestHeadersSpec<out RequestHeadersSpec<*>>.awaitExchange(responseHandler: suspend (ClientResponse) -> T): T =
-		exchangeToMono { mono(Dispatchers.Unconfined) { responseHandler.invoke(it) } }.awaitFirst()
+		exchangeToMono { mono(Dispatchers.Unconfined) { responseHandler.invoke(it) } }.awaitSingle()
 
 /**
  * Coroutines variant of [WebClient.RequestHeadersSpec.exchangeToFlux].

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

@@ -17,7 +17,7 @@
 package org.springframework.web.reactive.function.server
 
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.reactive.awaitFirst
+import kotlinx.coroutines.reactive.awaitSingle
 import kotlinx.coroutines.reactor.mono
 import org.springframework.core.io.Resource
 import org.springframework.http.HttpMethod
@@ -532,7 +532,7 @@ class CoRouterFunctionDsl internal constructor (private val init: (CoRouterFunct
 		builder.filter { serverRequest, handlerFunction ->
 			mono(Dispatchers.Unconfined) {
 				filterFunction(serverRequest) {
-					handlerFunction.handle(serverRequest).awaitFirst()
+					handlerFunction.handle(serverRequest).awaitSingle()
 				}
 			}
 		}

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

@@ -17,7 +17,7 @@
 package org.springframework.web.reactive.function.server
 
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.reactive.awaitFirstOrNull
+import kotlinx.coroutines.reactive.awaitSingleOrNull
 import kotlinx.coroutines.reactive.awaitSingle
 import kotlinx.coroutines.reactive.asFlow
 import org.springframework.core.ParameterizedTypeReference
@@ -99,7 +99,7 @@ suspend fun <T : Any> ServerRequest.awaitBody(clazz: KClass<T>): T =
  * @since 5.2
  */
 suspend inline fun <reified T : Any> ServerRequest.awaitBodyOrNull(): T? =
-		bodyToMono<T>().awaitFirstOrNull()
+		bodyToMono<T>().awaitSingleOrNull()
 
 /**
  * `KClass` nullable Coroutines variant of [ServerRequest.bodyToMono].
@@ -109,7 +109,7 @@ suspend inline fun <reified T : Any> ServerRequest.awaitBodyOrNull(): T? =
  * @since 5.3
  */
 suspend fun <T : Any> ServerRequest.awaitBodyOrNull(clazz: KClass<T>): T? =
-		bodyToMono(clazz.java).awaitFirstOrNull()
+		bodyToMono(clazz.java).awaitSingleOrNull()
 
 /**
  * Coroutines variant of [ServerRequest.formData].
@@ -136,7 +136,7 @@ suspend fun ServerRequest.awaitMultipartData(): MultiValueMap<String, Part> =
  * @since 5.2
  */
 suspend fun ServerRequest.awaitPrincipal(): Principal? =
-		principal().awaitFirstOrNull()
+		principal().awaitSingleOrNull()
 
 /**
  * Coroutines variant of [ServerRequest.session].

src/docs/asciidoc/data-access.adoc

@@ -6749,7 +6749,7 @@ The following query gets the `id` and `name` columns from a table:
 .Kotlin
 ----
 	val first = client.sql("SELECT id, name FROM person")
-	        .fetch().awaitFirst()
+	        .fetch().awaitSingle()
 ----
 
 The following query uses a bind variable:
@@ -6766,7 +6766,7 @@ The following query uses a bind variable:
 ----
 	val first = client.sql("SELECT id, name FROM person WHERE WHERE first_name = :fn")
 	        .bind("fn", "Joe")
-	        .fetch().awaitFirst()
+	        .fetch().awaitSingle()
 ----
 
 You might have noticed the use of `fetch()` in the example above. `fetch()` is a
@@ -6776,7 +6776,7 @@ Calling `first()` returns the first row from the result and discards remaining r
 You can consume data with the following operators:
 
 * `first()` return the first row of the entire result. Its Kotlin Coroutine variant
-is named `awaitFirst()` for non-nullable return values and `awaitFirstOrNull()`
+is named `awaitSingle()` for non-nullable return values and `awaitSingleOrNull()`
 if the value is optional.
 * `one()` returns exactly one result and fails if the result contains more rows.
 Using Kotlin Coroutines, `awaitOne()` for exactly one value or `awaitOneOrNull()`

src/docs/asciidoc/languages/kotlin.adoc

@@ -434,7 +434,7 @@ dependencies {
 }
 ----
 
-Version `1.3.9` and above are supported.
+Version `1.4.0-M1` and above are supported.
 
 === How Reactive translates to Coroutines?
 

src/docs/asciidoc/rsocket.adoc

@@ -601,7 +601,7 @@ Then start an RSocket server through the Java RSocket API and plug the
 
 	val server = RSocketServer.create(handler.responder())
 			.bind(TcpServerTransport.create("localhost", 7000))
-			.awaitFirst()
+			.awaitSingle()
 ----
 
 `RSocketMessageHandler` supports

src/docs/asciidoc/web/webflux-functional.adoc

@@ -172,7 +172,7 @@ Flux<Person> people = request.body(BodyExtractors.toFlux(Person.class));
 [source,kotlin,role="secondary"]
 .Kotlin
 ----
-	val string = request.body(BodyExtractors.toMono(String::class.java)).awaitFirst()
+	val string = request.body(BodyExtractors.toMono(String::class.java)).awaitSingle()
 	val people = request.body(BodyExtractors.toFlux(Person::class.java)).asFlow()
 ----