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 {