DATACASS-647 - Add non-nullable variant to ReactiveSelectOperation extensions.

Original pull request: #158.

Author: sdeleuze

spring-data-cassandra/src/main/kotlin/org/springframework/data/cassandra/core/ReactiveSelectOperationExtensions.kt

@@ -53,21 +53,39 @@ inline fun <reified T : Any> ReactiveSelectOperation.SelectWithProjection<*>.asT
 		`as`(T::class.java)
 
 /**
- * Coroutines variant of [ReactiveSelectOperation.TerminatingSelect.one].
+ * Non-nullable Coroutines variant of [ReactiveSelectOperation.TerminatingSelect.one].
  *
  * @author Mark Paluch
  * @since 2.2
  */
-suspend inline fun <reified T : Any> ReactiveSelectOperation.TerminatingSelect<T>.awaitOne(): T? =
+suspend inline fun <reified T : Any> ReactiveSelectOperation.TerminatingSelect<T>.awaitOne(): T =
+		one().awaitSingle()
+
+/**
+ * Nullable Coroutines variant of [ReactiveSelectOperation.TerminatingSelect.one].
+ *
+ * @author Mark Paluch
+ * @since 2.2
+ */
+suspend inline fun <reified T : Any> ReactiveSelectOperation.TerminatingSelect<T>.awaitOneOrNull(): T? =
 		one().awaitFirstOrNull()
 
 /**
- * Coroutines variant of [ReactiveSelectOperation.TerminatingSelect.first].
+ * Non-nullable Coroutines variant of [ReactiveSelectOperation.TerminatingSelect.first].
+ *
+ * @author Mark Paluch
+ * @since 2.2
+ */
+suspend inline fun <reified T : Any> ReactiveSelectOperation.TerminatingSelect<T>.awaitFirst(): T =
+		first().awaitSingle()
+
+/**
+ * Nullable Coroutines variant of [ReactiveSelectOperation.TerminatingSelect.first].
  *
  * @author Mark Paluch
  * @since 2.2
  */
-suspend inline fun <reified T : Any> ReactiveSelectOperation.TerminatingSelect<T>.awaitFirst(): T? =
+suspend inline fun <reified T : Any> ReactiveSelectOperation.TerminatingSelect<T>.awaitFirstOrNull(): T? =
 		first().awaitFirstOrNull()
 
 /**

spring-data-cassandra/src/test/kotlin/org/springframework/data/cassandra/core/ReactiveSelectOperationExtensionsUnitTests.kt

@@ -65,7 +65,7 @@ class ReactiveSelectOperationExtensionsUnitTests {
 	}
 
 	@Test // DATACASS-632
-	fun terminatingFindAwaitOne() {
+	fun terminatingFindAwaitOneWithValue() {
 
 		val find = mockk<ReactiveSelectOperation.TerminatingSelect<String>>()
 		every { find.one() } returns Mono.just("foo")
@@ -80,7 +80,52 @@ class ReactiveSelectOperationExtensionsUnitTests {
 	}
 
 	@Test // DATACASS-632
-	fun terminatingFindAwaitFirst() {
+	fun terminatingFindAwaitOneWithNull() {
+
+		val find = mockk<ReactiveSelectOperation.TerminatingSelect<String>>()
+		every { find.one() } returns Mono.empty()
+
+		Assertions.assertThatExceptionOfType(NoSuchElementException::class.java).isThrownBy {
+			runBlocking { find.awaitOne() }
+		}
+
+		verify {
+			find.one()
+		}
+	}
+
+	@Test // DATACASS-632
+	fun terminatingFindAwaitOneOrNullWithValue() {
+
+		val find = mockk<ReactiveSelectOperation.TerminatingSelect<String>>()
+		every { find.one() } returns Mono.just("foo")
+
+		runBlocking {
+			Assertions.assertThat(find.awaitOneOrNull()).isEqualTo("foo")
+		}
+
+		verify {
+			find.one()
+		}
+	}
+
+	@Test // DATACASS-632
+	fun terminatingFindAwaitOneOrNullWithNull() {
+
+		val find = mockk<ReactiveSelectOperation.TerminatingSelect<String>>()
+		every { find.one() } returns Mono.empty()
+
+		runBlocking {
+			Assertions.assertThat(find.awaitOneOrNull()).isNull()
+		}
+
+		verify {
+			find.one()
+		}
+	}
+
+	@Test // DATACASS-632
+	fun terminatingFindAwaitFirstWithValue() {
 
 		val find = mockk<ReactiveSelectOperation.TerminatingSelect<String>>()
 		every { find.first() } returns Mono.just("foo")
@@ -94,6 +139,51 @@ class ReactiveSelectOperationExtensionsUnitTests {
 		}
 	}
 
+	@Test // DATACASS-632
+	fun terminatingFindAwaitFirstWithNull() {
+
+		val find = mockk<ReactiveSelectOperation.TerminatingSelect<String>>()
+		every { find.first() } returns Mono.empty()
+
+		Assertions.assertThatExceptionOfType(NoSuchElementException::class.java).isThrownBy {
+			runBlocking { find.awaitFirst() }
+		}
+
+		verify {
+			find.first()
+		}
+	}
+
+	@Test // DATACASS-632
+	fun terminatingFindAwaitFirstOrNullWithValue() {
+
+		val find = mockk<ReactiveSelectOperation.TerminatingSelect<String>>()
+		every { find.first() } returns Mono.just("foo")
+
+		runBlocking {
+			Assertions.assertThat(find.awaitFirstOrNull()).isEqualTo("foo")
+		}
+
+		verify {
+			find.first()
+		}
+	}
+
+	@Test // DATACASS-632
+	fun terminatingFindAwaitFirstOrNullWithNull() {
+
+		val find = mockk<ReactiveSelectOperation.TerminatingSelect<String>>()
+		every { find.first() } returns Mono.empty()
+
+		runBlocking {
+			Assertions.assertThat(find.awaitFirstOrNull()).isNull()
+		}
+
+		verify {
+			find.first()
+		}
+	}
+
 	@Test // DATACASS-632
 	fun terminatingFindAwaitCount() {