Merge branch '5.1.x'

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/DefaultWebClient.java

@@ -463,9 +463,15 @@ class DefaultWebClient implements WebClient {
 				for (StatusHandler handler : this.statusHandlers) {
 					if (handler.test(response.statusCode())) {
 						HttpRequest request = this.requestSupplier.get();
-						Mono<? extends Throwable> exMono = handler.apply(response, request);
-						exMono = exMono.flatMap(ex -> drainBody(response, ex));
-						exMono = exMono.onErrorResume(ex -> drainBody(response, ex));
+						Mono<? extends Throwable> exMono;
+						try {
+							exMono = handler.apply(response, request);
+							exMono = exMono.flatMap(ex -> drainBody(response, ex));
+							exMono = exMono.onErrorResume(ex -> drainBody(response, ex));
+						}
+						catch (Throwable ex2) {
+							exMono = drainBody(response, ex2);
+						}
 						T result = errorFunction.apply(exMono);
 						return insertCheckpoint(result, response.statusCode(), request);
 					}

spring-webflux/src/test/java/org/springframework/web/reactive/function/client/WebClientDataBufferAllocatingTests.java

@@ -147,6 +147,15 @@ public class WebClientDataBufferAllocatingTests extends AbstractDataBufferAlloca
 		testOnStatus(ex, response -> response.bodyToMono(Void.class).then(Mono.error(ex)));
 	}
 
+	@Test // gh-23230
+	public void onStatusWithImmediateErrorAndBodyNotConsumed() {
+		RuntimeException ex = new RuntimeException("response error");
+		testOnStatus(ex, response -> {
+			throw ex;
+		});
+	}
+
+
 	private void testOnStatus(Throwable expected,
 			Function<ClientResponse, Mono<? extends Throwable>> exceptionFunction) {
 

src/docs/asciidoc/testing.adoc

@@ -5079,20 +5079,43 @@ resulting links by using XPath expressions:
 		.andExpect(xpath("/person/ns:link[@rel='self']/@href", ns).string("http://localhost:8080/people"));
 ----
 
-[[spring-mvc-test-server-filters]]
-===== Filter Registrations
 
-When setting up a `MockMvc` instance, you can register one or more Servlet `Filter`
-instances, as the following example shows:
+[[spring-mvc-test-async-requests]]
+===== Async Requests
+
+Servlet 3.0 asynchronous requests,
+<<web.adoc#mvc-ann-async,supported in Spring MVC>>, work by exiting the Servlet container
+thread and allowing the application to compute the response asynchronously, after which
+an async dispatch is made to complete processing on a Servlet container thread.
+
+In Spring MVC Test, async requests can be tested by asserting the produced async value
+first, then manually performing the async dispatch, and finally verifying the response.
+Below is an example test for controller methods that return `DeferredResult`, `Callable`,
+or reactive type such as Reactor `Mono`:
 
 [source,java,indent=0]
 [subs="verbatim,quotes"]
 ----
-	mockMvc = standaloneSetup(new PersonController()).addFilters(new CharacterEncodingFilter()).build();
+@Test
+public void test() throws Exception {
+	MvcResult mvcResult = this.mockMvc.perform(get("/path"))
+		.andExpect(status().isOk()) <1>
+		.andExpect(request().asyncStarted()) <2>
+		.andExpect(request().asyncResult("body")) <3>
+		.andReturn();
+
+	this.mockMvc.perform(asyncDispatch(mvcResult)) <4>
+		.andExpect(status().isOk()) <5>
+		.andExpect(content().string("body"));
+}
 ----
+<1> Check response status is still unchanged
+<2> Async processing must have started
+<3> Wait and assert the async result
+<4> Manually perform an ASYNC dispatch (as there is no running container)
+<5> Verify the final response
 
-Registered filters are invoked through the `MockFilterChain` from `spring-test`, and the
-last filter delegates to the `DispatcherServlet`.
+====
 
 
 [[spring-mvc-test-vs-streaming-response]]
@@ -5108,13 +5131,31 @@ with `WebTestClient`. One extra advantage is the ability to use the `StepVerifie
 project Reactor that allows declaring expectations on a stream of data.
 
 
+[[spring-mvc-test-server-filters]]
+===== Filter Registrations
+
+When setting up a `MockMvc` instance, you can register one or more Servlet `Filter`
+instances, as the following example shows:
+
+====
+[source,java,indent=0]
+[subs="verbatim,quotes"]
+----
+	mockMvc = standaloneSetup(new PersonController()).addFilters(new CharacterEncodingFilter()).build();
+----
+====
+
+Registered filters are invoked through the `MockFilterChain` from `spring-test`, and the
+last filter delegates to the `DispatcherServlet`.
+
+
 [[spring-mvc-test-vs-end-to-end-integration-tests]]
-===== Differences Between Out-of-Container and End-to-End Integration Tests
+===== Spring MVC Test vs End-to-End Tests
 
-As mentioned earlier Spring MVC Test is built on the Servlet API mock objects from the
-`spring-test` module and does not use a running Servlet container. Therefore, there are
-some important differences compared to full end-to-end integration tests with an actual
-client and server running.
+Spring MVC Test is built on Servlet API mock implementations from the
+`spring-test` module and does not rely on a running container. Therefore, there are
+some differences when compared to full end-to-end integration tests with an actual
+client and a live server running.
 
 The easiest way to think about this is by starting with a blank `MockHttpServletRequest`.
 Whatever you add to it is what the request becomes. Things that may catch you by surprise
@@ -5155,7 +5196,7 @@ important thing to check. In short, there is room here for multiple styles and s
 of testing even within the same project.
 
 [[spring-mvc-test-server-resources]]
-===== Further Server-Side Test Examples
+===== Further Examples
 
 The framework's own tests include
 https://github.com/spring-projects/spring-framework/tree/master/spring-test/src/test/java/org/springframework/test/web/servlet/samples[many