Respect async request timeout of -1 in MockMvc

When falling back on the timeout associated with the async request,
a value of -1 must be treated as: never time out.

Issue: SPR-16869

spring-test/src/main/java/org/springframework/mock/web/MockAsyncContext.java

@@ -154,6 +154,17 @@ public class MockAsyncContext implements AsyncContext {
 		return BeanUtils.instantiateClass(clazz);
 	}
 
+	/**
+	 * By default this is set to 10000 (10 seconds) even though the Servlet API
+	 * specifies a default async request timeout of 30 seconds. Keep in mind the
+	 * timeout could further be impacted by global configuration through the MVC
+	 * Java config or the XML namespace, as well as be overridden per request on
+	 * {@link org.springframework.web.context.request.async.DeferredResult DeferredResult}
+	 * or on
+	 * {@link org.springframework.web.servlet.mvc.method.annotation.SseEmitter SseEmitter}.
+	 * @param timeout the timeout value to use.
+	 * @see AsyncContext#setTimeout(long)
+	 */
 	@Override
 	public void setTimeout(long timeout) {
 		this.timeout = timeout;

spring-test/src/main/java/org/springframework/test/web/servlet/DefaultMvcResult.java

@@ -138,8 +138,9 @@ class DefaultMvcResult implements MvcResult {
 
 	@Override
 	public Object getAsyncResult(long timeToWait) {
-		if (this.mockRequest.getAsyncContext() != null) {
+		if (this.mockRequest.getAsyncContext() != null && timeToWait == -1) {
-			timeToWait = (timeToWait == -1 ? this.mockRequest.getAsyncContext().getTimeout() : timeToWait);
+			long requestTimeout = this.mockRequest.getAsyncContext().getTimeout();
+			timeToWait = requestTimeout == -1 ? Long.MAX_VALUE : requestTimeout;
 		}
 		if (!awaitAsyncDispatch(timeToWait)) {
 			throw new IllegalStateException("Async result for handler [" + this.handler + "]" +

spring-test/src/main/java/org/springframework/test/web/servlet/MvcResult.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License; Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -80,19 +80,23 @@ public interface MvcResult {
 	FlashMap getFlashMap();
 
 	/**
-	 * Get the result of async execution. This method will wait for the async result
+	 * Get the result of async execution.
-	 * to be set for up to the amount of time configured on the async request,
+	 * <p>This method will wait for the async result to be set within the
-	 * i.e. {@link org.springframework.mock.web.MockAsyncContext#getTimeout()}.
+	 * timeout value associated with the async request, see
+	 * {@link org.springframework.mock.web.MockAsyncContext#setTimeout
+	 * MockAsyncContext#setTimeout}. Alternatively, use
+	 * {@link #getAsyncResult(long)} to specify the amount of time to wait.
 	 * @throws IllegalStateException if the async result was not set
 	 */
 	Object getAsyncResult();
 
 	/**
-	 * Get the result of async execution. This method will wait for the async result
+	 * Get the result of async execution and wait if necessary.
-	 * to be set for up to the specified amount of time.
 	 * @param timeToWait how long to wait for the async result to be set, in
-	 * 	milliseconds; if -1, then the async request timeout value is used,
+	 * 	milliseconds; if -1, then fall back on the timeout value associated with
-	 *  i.e.{@link org.springframework.mock.web.MockAsyncContext#getTimeout()}.
+	 * 	the async request, see
+	 * 	{@link org.springframework.mock.web.MockAsyncContext#setTimeout
+	 * 	MockAsyncContext#setTimeout} for more details.
 	 * @throws IllegalStateException if the async result was not set
 	 */
 	Object getAsyncResult(long timeToWait);

spring-test/src/test/java/org/springframework/test/web/servlet/samples/standalone/ReactiveReturnTypeTests.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.test.web.servlet.samples.standalone;
+
+import java.time.Duration;
+
+import org.junit.Test;
+import reactor.core.publisher.Flux;
+
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.MvcResult;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.request;
+
+/**
+ * Tests with reactive return value types.
+ *
+ * @author Rossen Stoyanchev
+ */
+public class ReactiveReturnTypeTests {
+
+
+	@Test // SPR-16869
+	public void sseWithFlux() throws Exception {
+
+		MockMvc mockMvc = MockMvcBuilders.standaloneSetup(ReactiveController.class).build();
+
+		MvcResult mvcResult = mockMvc.perform(get("/spr16869"))
+				.andExpect(request().asyncStarted())
+				.andExpect(status().isOk())
+				.andReturn();
+
+		mockMvc.perform(asyncDispatch(mvcResult))
+				.andExpect(content().string("data:event0\n\ndata:event1\n\ndata:event2\n\n"));
+	}
+
+
+
+	@RestController
+	static class ReactiveController {
+
+		@GetMapping(path = "/spr16869", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
+		Flux<String> sseFlux() {
+			return Flux.interval(Duration.ofSeconds(1)).take(3)
+					.map(aLong -> String.format("event%d", aLong));
+		}
+	}
+
+}