MockMvcHttpConnector supports RequestPostProcessor's

Closes gh-31298

spring-test/src/main/java/org/springframework/test/web/reactive/server/DefaultWebTestClientBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -80,7 +80,7 @@ class DefaultWebTestClientBuilder implements WebTestClient.Builder {
 	private final WebHttpHandlerBuilder httpHandlerBuilder;
 
 	@Nullable
-	private final ClientHttpConnector connector;
+	private ClientHttpConnector connector;
 
 	@Nullable
 	private String baseUrl;
@@ -277,6 +277,12 @@ class DefaultWebTestClientBuilder implements WebTestClient.Builder {
 		return this;
 	}
 
+	@Override
+	public WebTestClient.Builder clientConnector(ClientHttpConnector connector) {
+		this.connector = connector;
+		return this;
+	}
+
 	@Override
 	public WebTestClient build() {
 		ClientHttpConnector connectorToUse = this.connector;

spring-test/src/main/java/org/springframework/test/web/reactive/server/WebTestClient.java

@@ -512,6 +512,18 @@ public interface WebTestClient {
 		 */
 		Builder responseTimeout(Duration timeout);
 
+		/**
+		 * Set the {@link ClientHttpConnector} to use.
+		 * <p>By default, this is initialized and set internally. However, the
+		 * connector may also be prepared externally and passed via
+		 * {@link WebTestClient#bindToServer(ClientHttpConnector)} such as for
+		 * {@code MockMvcWebTestClient} tests, and in that case you can use this
+		 * from {@link #mutateWith(WebTestClientConfigurer)} to replace it.
+		 * @param connector the connector to use
+		 * @since 6.1
+		 */
+		Builder clientConnector(ClientHttpConnector connector);
+
 		/**
 		 * Apply the given configurer to this builder instance.
 		 * <p>This can be useful for applying pre-packaged customizations.

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

@@ -19,6 +19,7 @@ package org.springframework.test.web.servlet.client;
 import java.io.StringWriter;
 import java.net.URI;
 import java.time.Duration;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicReference;
@@ -56,6 +57,7 @@ import org.springframework.test.web.servlet.RequestBuilder;
 import org.springframework.test.web.servlet.request.MockHttpServletRequestBuilder;
 import org.springframework.test.web.servlet.request.MockMultipartHttpServletRequestBuilder;
 import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
+import org.springframework.test.web.servlet.request.RequestPostProcessor;
 import org.springframework.test.web.servlet.result.MockMvcResultHandlers;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
@@ -82,9 +84,16 @@ public class MockMvcHttpConnector implements ClientHttpConnector {
 
 	private final MockMvc mockMvc;
 
+	private final List<RequestPostProcessor> requestPostProcessors;
+
 
 	public MockMvcHttpConnector(MockMvc mockMvc) {
+		this(mockMvc, Collections.emptyList());
+	}
+
+	private MockMvcHttpConnector(MockMvc mockMvc, List<RequestPostProcessor> requestPostProcessors) {
 		this.mockMvc = mockMvc;
+		this.requestPostProcessors = new ArrayList<>(requestPostProcessors);
 	}
 
 
@@ -135,6 +144,8 @@ public class MockMvcHttpConnector implements ClientHttpConnector {
 			}
 		}
 
+		this.requestPostProcessors.forEach(requestBuilder::with);
+
 		return requestBuilder;
 	}
 
@@ -207,6 +218,15 @@ public class MockMvcHttpConnector implements ClientHttpConnector {
 		return clientResponse;
 	}
 
+	/**
+	 * Create a new instance that applies the given {@link RequestPostProcessor}s
+	 * to performed requests.
+	 * @since 6.1
+	 */
+	public MockMvcHttpConnector with(List<RequestPostProcessor> postProcessors) {
+		return new MockMvcHttpConnector(this.mockMvc, postProcessors);
+	}
+
 
 	private static class MockMvcServerClientHttpResponse
 			extends MockClientHttpResponse implements MockServerClientHttpResponse {

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

@@ -17,11 +17,17 @@
 package org.springframework.test.web.servlet.samples.client.standalone;
 
 import java.security.Principal;
+import java.util.List;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.client.reactive.ClientHttpConnector;
+import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.stereotype.Controller;
 import org.springframework.test.web.reactive.server.WebTestClient;
+import org.springframework.test.web.reactive.server.WebTestClientConfigurer;
+import org.springframework.test.web.servlet.client.MockMvcHttpConnector;
 import org.springframework.test.web.servlet.client.MockMvcWebTestClient;
 import org.springframework.test.web.servlet.request.RequestPostProcessor;
 import org.springframework.test.web.servlet.setup.ConfigurableMockMvcBuilder;
@@ -30,6 +36,7 @@ import org.springframework.util.Assert;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.context.WebApplicationContext;
+import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
 
 import static org.mockito.Mockito.mock;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
@@ -50,16 +57,16 @@ public class FrameworkExtensionTests {
 
 	@Test
 	public void fooHeader() {
-		this.client.get().uri("/")
+		this.client.mutateWith(headers().foo("a=b"))
-				.header("Foo", "a=b")
+				.get().uri("/")
 				.exchange()
 				.expectBody(String.class).isEqualTo("Foo");
 	}
 
 	@Test
 	public void barHeader() {
-		this.client.get().uri("/")
+		this.client.mutateWith(headers().bar("a=b"))
-				.header("Bar", "a=b")
+				.get().uri("/")
 				.exchange()
 				.expectBody(String.class).isEqualTo("Bar");
 	}
@@ -68,6 +75,68 @@ public class FrameworkExtensionTests {
 		return new TestMockMvcConfigurer();
 	}
 
+	private static TestWebTestClientConfigurer headers() {
+		return new TestWebTestClientConfigurer();
+	}
+
+
+	/**
+	 * Test WebTestClientConfigurer that re-creates the MockMvcHttpConnector
+	 * with a {@code TestRequestPostProcessor}.
+	 */
+	private static class TestWebTestClientConfigurer implements WebTestClientConfigurer {
+
+		private final TestRequestPostProcessor requestPostProcessor = new TestRequestPostProcessor();
+
+		public TestWebTestClientConfigurer foo(String value) {
+			this.requestPostProcessor.foo(value);
+			return this;
+		}
+
+		public TestWebTestClientConfigurer bar(String value) {
+			this.requestPostProcessor.bar(value);
+			return this;
+		}
+
+		@Override
+		public void afterConfigurerAdded(
+				WebTestClient.Builder builder, WebHttpHandlerBuilder httpHandlerBuilder,
+				ClientHttpConnector connector) {
+
+			if (connector instanceof MockMvcHttpConnector mockMvcConnector) {
+				builder.clientConnector(mockMvcConnector.with(List.of(this.requestPostProcessor)));
+			}
+		}
+	}
+
+
+	/**
+	 * Test {@code RequestPostProcessor} for custom headers.
+	 */
+	private static class TestRequestPostProcessor implements RequestPostProcessor {
+
+		private final HttpHeaders headers = new HttpHeaders();
+
+
+		public TestRequestPostProcessor foo(String value) {
+			this.headers.add("Foo", value);
+			return this;
+		}
+
+		public TestRequestPostProcessor bar(String value) {
+			this.headers.add("Bar", value);
+			return this;
+		}
+
+		@Override
+		public MockHttpServletRequest postProcessRequest(MockHttpServletRequest request) {
+			for (String headerName : this.headers.keySet()) {
+				request.addHeader(headerName, this.headers.get(headerName));
+			}
+			return request;
+		}
+	}
+
 
 	/**
 	 * Test {@code MockMvcConfigurer}.
@@ -80,8 +149,9 @@ public class FrameworkExtensionTests {
 		}
 
 		@Override
-		public RequestPostProcessor beforeMockMvcCreated(ConfigurableMockMvcBuilder<?> builder,
+		public RequestPostProcessor beforeMockMvcCreated(
-				WebApplicationContext context) {
+				ConfigurableMockMvcBuilder<?> builder, WebApplicationContext context) {
+
 			return request -> {
 				request.setUserPrincipal(mock());
 				return request;

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

@@ -18,7 +18,6 @@ package org.springframework.test.web.servlet.samples.standalone;
 
 import java.security.Principal;
 
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.http.HttpHeaders;
@@ -53,14 +52,9 @@ import static org.springframework.test.web.servlet.setup.MockMvcBuilders.standal
  */
 public class FrameworkExtensionTests {
 
-	private MockMvc mockMvc;
+	private final MockMvc mockMvc = standaloneSetup(new SampleController()).apply(defaultSetup()).build();
 
 
-	@BeforeEach
-	public void setup() {
-		this.mockMvc = standaloneSetup(new SampleController()).apply(defaultSetup()).build();
-	}
-
 	@Test
 	public void fooHeader() throws Exception {
 		this.mockMvc.perform(get("/").with(headers().foo("a=b"))).andExpect(content().string("Foo"));
@@ -81,7 +75,7 @@ public class FrameworkExtensionTests {
 
 
 	/**
-	 * Test {@code RequestPostProcessor}.
+	 * Test {@code RequestPostProcessor} for custom headers.
 	 */
 	private static class TestRequestPostProcessor implements RequestPostProcessor {
 
@@ -119,8 +113,9 @@ public class FrameworkExtensionTests {
 		}
 
 		@Override
-		public RequestPostProcessor beforeMockMvcCreated(ConfigurableMockMvcBuilder<?> builder,
+		public RequestPostProcessor beforeMockMvcCreated(
-				WebApplicationContext context) {
+				ConfigurableMockMvcBuilder<?> builder, WebApplicationContext context) {
+
 			return request -> {
 				request.setUserPrincipal(mock());
 				return request;