Expose MockMvc in API

Fixes gh-31275

Signed-off-by: Rob Worsnop <rworsnop@gmail.com>

Author: rworsnop

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

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2002-present 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
+ *
+ *      https://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.client;
+
+import java.util.function.Consumer;
+
+import org.springframework.test.web.servlet.MockMvcBuilder;
+
+/**
+ * Default implementation of {@link RestTestClient.MockServerBuilder}.
+ * @author Rob Worsnop
+ * @param <M> the type of the {@link MockMvcBuilder} to use for building the mock server
+ */
+class DefaultMockServerBuilder<M extends MockMvcBuilder>
+		extends DefaultRestTestClientBuilder<RestTestClient.MockServerBuilder<M>>
+		implements RestTestClient.MockServerBuilder<M> {
+
+	private final M builder;
+
+	public DefaultMockServerBuilder(M builder) {
+		this.builder = builder;
+	}
+
+	@Override
+	public RestTestClient.MockServerBuilder<M> configureServer(Consumer<M> consumer) {
+		consumer.accept(this.builder);
+		return this;
+	}
+
+	@Override
+	public RestTestClient build() {
+		this.restClientBuilder.requestFactory(new MockMvcClientHttpRequestFactory(this.builder.build()));
+		return super.build();
+	}
+}

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

@@ -105,8 +105,8 @@ public RequestBodyUriSpec method(HttpMethod method) {
 	}
 
 	@Override
-	public Builder mutate() {
-		return new DefaultRestTestClientBuilder(this.restClientBuilder);
+	public <B extends Builder<B>> Builder<B> mutate() {
+		return new DefaultRestTestClientBuilder<>(this.restClientBuilder);
 	}
 
 	private RequestBodyUriSpec methodInternal(HttpMethod httpMethod) {

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

@@ -25,12 +25,12 @@
 
 /**
  * Default implementation of {@link RestTestClient.Builder}.
- *
  * @author Rob Worsnop
+ * @param <B> the type of the builder
  */
-class DefaultRestTestClientBuilder implements RestTestClient.Builder {
+class DefaultRestTestClientBuilder<B extends RestTestClient.Builder<B>> implements RestTestClient.Builder<B> {
 
-	private final RestClient.Builder restClientBuilder;
+	protected final RestClient.Builder restClientBuilder;
 
 	DefaultRestTestClientBuilder() {
 		this.restClientBuilder = RestClient.builder();
@@ -41,43 +41,43 @@ class DefaultRestTestClientBuilder implements RestTestClient.Builder {
 	}
 
 	@Override
-	public RestTestClient.Builder apply(Consumer<RestTestClient.Builder> builderConsumer) {
+	public RestTestClient.Builder<B> apply(Consumer<RestTestClient.Builder<B>> builderConsumer) {
 		builderConsumer.accept(this);
 		return this;
 	}
 
 	@Override
-	public RestTestClient.Builder baseUrl(String baseUrl) {
+	public RestTestClient.Builder<B> baseUrl(String baseUrl) {
 		this.restClientBuilder.baseUrl(baseUrl);
 		return this;
 	}
 
 	@Override
-	public RestTestClient.Builder defaultCookie(String cookieName, String... cookieValues) {
+	public RestTestClient.Builder<B> defaultCookie(String cookieName, String... cookieValues) {
 		this.restClientBuilder.defaultCookie(cookieName, cookieValues);
 		return this;
 	}
 
 	@Override
-	public RestTestClient.Builder defaultCookies(Consumer<MultiValueMap<String, String>> cookiesConsumer) {
+	public RestTestClient.Builder<B> defaultCookies(Consumer<MultiValueMap<String, String>> cookiesConsumer) {
 		this.restClientBuilder.defaultCookies(cookiesConsumer);
 		return this;
 	}
 
 	@Override
-	public RestTestClient.Builder defaultHeader(String headerName, String... headerValues) {
+	public RestTestClient.Builder<B> defaultHeader(String headerName, String... headerValues) {
 		this.restClientBuilder.defaultHeader(headerName, headerValues);
 		return this;
 	}
 
 	@Override
-	public RestTestClient.Builder defaultHeaders(Consumer<HttpHeaders> headersConsumer) {
+	public RestTestClient.Builder<B> defaultHeaders(Consumer<HttpHeaders> headersConsumer) {
 		this.restClientBuilder.defaultHeaders(headersConsumer);
 		return this;
 	}
 
 	@Override
-	public RestTestClient.Builder uriBuilderFactory(UriBuilderFactory uriFactory) {
+	public RestTestClient.Builder<B> uriBuilderFactory(UriBuilderFactory uriFactory) {
 		this.restClientBuilder.uriBuilderFactory(uriFactory);
 		return this;
 	}