Fix codec customization with AutoConfigureWebTestClient

Fixes gh-47697

module/spring-boot-webtestclient/build.gradle

@@ -16,9 +16,9 @@
 
 plugins {
 	id "java-library"
-	id "org.springframework.boot.auto-configuration"
 	id "org.springframework.boot.deployed"
 	id "org.springframework.boot.optional-dependencies"
+	id "org.springframework.boot.test-auto-configuration"
 }
 
 description = "Spring Boot WebTestClient"
@@ -32,6 +32,7 @@ dependencies {
 
 	testImplementation(project(":core:spring-boot-test"))
 	testImplementation(project(":test-support:spring-boot-test-support"))
+	testImplementation(testFixtures(project(":core:spring-boot-autoconfigure")))
 
 	testRuntimeOnly("ch.qos.logback:logback-classic")
 	testRuntimeOnly("jakarta.servlet:jakarta.servlet-api")

module/spring-boot-webtestclient/src/main/resources/META-INF/spring/org.springframework.boot.webtestclient.AutoConfigureWebTestClient.imports

@@ -1 +1,2 @@
+org.springframework.boot.http.codec.autoconfigure.CodecsAutoConfiguration
 org.springframework.boot.webtestclient.WebTestClientAutoConfiguration

module/spring-boot-webtestclient/src/test/java/org/springframework/boot/webflux/test/autoconfigure/AutoConfigureWebTestClientIntegrationTests.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2012-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.boot.webflux.test.autoconfigure;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.http.codec.autoconfigure.CodecsAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.webtestclient.AutoConfigureWebTestClient;
+import org.springframework.context.ApplicationContext;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.boot.autoconfigure.AutoConfigurationImportedCondition.importedAutoConfiguration;
+
+/**
+ * Integration tests for {@link AutoConfigureWebTestClient @AutoConfigureWebTestClient}.
+ *
+ * @author Andy Wilkinson
+ */
+@SpringBootTest
+@AutoConfigureWebTestClient
+class AutoConfigureWebTestClientIntegrationTests {
+
+	@Autowired
+	private ApplicationContext applicationContext;
+
+	@Test
+	void codecsAutoConfigurationIsImported() {
+		assertThat(this.applicationContext).has(importedAutoConfiguration(CodecsAutoConfiguration.class));
+	}
+
+	@SpringBootConfiguration
+	static class TestConfiguration {
+
+	}
+
+}