Properly handle Flux<?> and Flux<Object> in WebFlux

Issue: SPR-15464

spring-webflux/src/test/java/org/springframework/web/reactive/result/method/annotation/ResponseEntityResultHandlerTests.java

@@ -29,6 +29,7 @@ import java.util.concurrent.CompletableFuture;
 
 import org.junit.Before;
 import org.junit.Test;
+import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 import rx.Completable;
@@ -132,6 +133,10 @@ public class ResponseEntityResultHandlerTests {
 
 		returnType = on(TestController.class).resolveReturnType(Completable.class);
 		assertFalse(this.resultHandler.supports(handlerResult(value, returnType)));
+
+		// SPR-15464
+		returnType = on(TestController.class).resolveReturnType(Flux.class);
+		assertFalse(this.resultHandler.supports(handlerResult(value, returnType)));
 	}
 
 	@Test
@@ -381,6 +386,7 @@ public class ResponseEntityResultHandlerTests {
 
 		Mono<ResponseEntity<?>> monoResponseEntityWildcard() { return null; }
 
+		Flux<?> fluxWildcard() { return null; }
 	}
 
 }

spring-webflux/src/test/java/org/springframework/web/reactive/result/view/ViewResolutionResultHandlerTests.java

@@ -97,6 +97,9 @@ public class ViewResolutionResultHandlerTests {
 
 		testSupports(on(Handler.class).annotPresent(ModelAttribute.class).resolveReturnType(Long.class));
 		testDoesNotSupport(on(Handler.class).annotNotPresent(ModelAttribute.class).resolveReturnType(Long.class));
+
+		// SPR-15464
+		testSupports(on(Handler.class).resolveReturnType(Mono.class));
 	}
 
 	private void testSupports(MethodParameter returnType) {
@@ -427,6 +430,7 @@ public class ViewResolutionResultHandlerTests {
 		Long longValue() { return null; }
 		@ModelAttribute("myLong") Long longModelAttribute() { return null; }
 
+		Mono<?> monoWildcard() { return null; }
 	}
 
 }