Merge pull request #46605 from nosan

* gh-46605:
  Add support for the @FilterRegistration annotation with @WebMvcTest

Closes gh-46605

spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/servlet/SpringBootMockMvcBuilderCustomizer.java

@@ -20,10 +20,13 @@ import java.io.PrintStream;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
+import java.util.EnumSet;
 import java.util.List;
 
 import jakarta.servlet.Filter;
+import jakarta.servlet.annotation.WebInitParam;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
@@ -31,11 +34,13 @@ import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.boot.web.servlet.AbstractFilterRegistrationBean;
 import org.springframework.boot.web.servlet.DelegatingFilterProxyRegistrationBean;
+import org.springframework.boot.web.servlet.FilterRegistration;
 import org.springframework.boot.web.servlet.FilterRegistrationBean;
 import org.springframework.boot.web.servlet.RegistrationBean;
 import org.springframework.boot.web.servlet.ServletContextInitializerBeans;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.core.annotation.Order;
 import org.springframework.test.web.servlet.MvcResult;
 import org.springframework.test.web.servlet.ResultHandler;
 import org.springframework.test.web.servlet.result.PrintingResultHandler;
@@ -330,18 +335,49 @@ public class SpringBootMockMvcBuilderCustomizer implements MockMvcBuilderCustomi
 
 		@Override
 		protected void addAdaptableBeans(ListableBeanFactory beanFactory) {
-			addAsRegistrationBean(beanFactory, Filter.class, new FilterRegistrationBeanAdapter());
+			addAsRegistrationBean(beanFactory, Filter.class, new FilterRegistrationBeanAdapter(beanFactory));
 		}
 
 		private static final class FilterRegistrationBeanAdapter implements RegistrationBeanAdapter<Filter> {
 
+			private final ListableBeanFactory beanFactory;
+
+			private FilterRegistrationBeanAdapter(ListableBeanFactory beanFactory) {
+				this.beanFactory = beanFactory;
+			}
+
 			@Override
-			public RegistrationBean createRegistrationBean(String name, Filter source, int totalNumberOfSourceBeans) {
+			public RegistrationBean createRegistrationBean(String beanName, Filter source,
+					int totalNumberOfSourceBeans) {
 				FilterRegistrationBean<Filter> bean = new FilterRegistrationBean<>(source);
-				bean.setName(name);
+				bean.setName(beanName);
+				FilterRegistration registrationAnnotation = this.beanFactory.findAnnotationOnBean(beanName,
+						FilterRegistration.class);
+				if (registrationAnnotation != null) {
+					// Supports @Order annotation on @Bean methods
+					Order orderAnnotation = this.beanFactory.findAnnotationOnBean(beanName, Order.class);
+					Assert.state(orderAnnotation != null, "'orderAnnotation' must not be null");
+					configureFromAnnotation(bean, registrationAnnotation, orderAnnotation);
+				}
 				return bean;
 			}
 
+			private void configureFromAnnotation(FilterRegistrationBean<Filter> bean,
+					FilterRegistration registrationAnnotation, Order orderAnnotation) {
+				bean.setEnabled(registrationAnnotation.enabled());
+				bean.setOrder(orderAnnotation.value());
+				if (StringUtils.hasText(registrationAnnotation.name())) {
+					bean.setName(registrationAnnotation.name());
+				}
+				if (registrationAnnotation.dispatcherTypes().length > 0) {
+					bean.setDispatcherTypes(EnumSet.copyOf(Arrays.asList(registrationAnnotation.dispatcherTypes())));
+				}
+				for (WebInitParam param : registrationAnnotation.initParameters()) {
+					bean.addInitParameter(param.name(), param.value());
+				}
+				bean.setUrlPatterns(Arrays.asList(registrationAnnotation.urlPatterns()));
+			}
+
 		}
 
 	}

spring-boot-project/spring-boot-test-autoconfigure/src/test/java/org/springframework/boot/test/autoconfigure/web/servlet/mockmvc/WebMvcTestServletFilterRegistrationIntegrationTests.java

@@ -0,0 +1,116 @@
+/*
+ * 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.test.autoconfigure.web.servlet.mockmvc;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Map;
+
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.FilterConfig;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.annotation.WebInitParam;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.security.SecurityProperties;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.boot.web.servlet.FilterRegistration;
+import org.springframework.boot.web.servlet.FilterRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.core.annotation.Order;
+import org.springframework.test.web.servlet.assertj.MockMvcTester;
+import org.springframework.web.filter.OncePerRequestFilter;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link FilterRegistration} and {@link FilterRegistrationBean} with
+ * {@link WebMvcTest @WebMvcTest}.
+ *
+ * @author Dmytro Nosan
+ */
+@WebMvcTest
+class WebMvcTestServletFilterRegistrationIntegrationTests {
+
+	@Autowired
+	private MockMvcTester mvc;
+
+	@Test
+	void annotation() {
+		assertThat(this.mvc.get().uri("/annotation")).headers()
+			.hasValue("name", "annotation")
+			.hasValue("param1", "value1")
+			.hasValue("param2", "value2")
+			.doesNotContainHeader("param3")
+			.doesNotContainHeader("param4");
+	}
+
+	@Test
+	void registration() {
+		assertThat(this.mvc.get().uri("/registration")).headers()
+			.hasValue("name", "registration")
+			.hasValue("param3", "value3")
+			.hasValue("param4", "value4")
+			.doesNotContainHeader("param1")
+			.doesNotContainHeader("param2");
+	}
+
+	@TestConfiguration(proxyBeanMethods = false)
+	static class FilterRegistrationConfiguration {
+
+		@Bean
+		@FilterRegistration(name = "annotation", urlPatterns = "/annotation",
+				initParameters = { @WebInitParam(name = "param1", value = "value1"),
+						@WebInitParam(name = "param2", value = "value2") })
+		@Order(SecurityProperties.DEFAULT_FILTER_ORDER - 1)
+		TestFilter testFilterAnnotationBean() {
+			return new TestFilter();
+		}
+
+		@Bean
+		FilterRegistrationBean<TestFilter> testFilterRegistrationBean() {
+			FilterRegistrationBean<TestFilter> registration = new FilterRegistrationBean<>(new TestFilter());
+			registration.setName("registration");
+			registration.addUrlPatterns("/registration");
+			registration.setInitParameters(Map.of("param3", "value3", "param4", "value4"));
+			registration.setOrder(SecurityProperties.DEFAULT_FILTER_ORDER - 1);
+			return registration;
+		}
+
+	}
+
+	private static final class TestFilter extends OncePerRequestFilter {
+
+		@Override
+		protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
+				FilterChain filterChain) throws ServletException, IOException {
+			response.addHeader("name", getFilterName());
+			FilterConfig config = getFilterConfig();
+			if (config != null) {
+				Collections.list(config.getInitParameterNames())
+					.forEach((name) -> response.addHeader(name, config.getInitParameter(name)));
+			}
+			filterChain.doFilter(request, response);
+		}
+
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/servlet/ServletContextInitializerBeans.java

@@ -330,7 +330,13 @@ public class ServletContextInitializerBeans extends AbstractCollection<ServletCo
 	}
 
 	/**
-	 * {@link RegistrationBeanAdapter} for {@link Filter} beans.
+	 * {@link RegistrationBeanAdapter} implementation for {@link Filter} beans.
+	 * <p>
+	 * <b>NOTE:</b> A similar implementation is used in
+	 * {@code SpringBootMockMvcBuilderCustomizer} for registering
+	 * {@code @FilterRegistration} beans with {@code @MockMvc}. If you modify this class,
+	 * please also update {@code SpringBootMockMvcBuilderCustomizer} if needed.
+	 * </p>
 	 */
 	private static class FilterRegistrationBeanAdapter implements RegistrationBeanAdapter<Filter> {