Make SslInfo nullable

This allows autowiring a MockServerSpec in test class and using a different
identity or none at all with each test.

Polishing in MockServerSpecTests.

See gh-35042

Author: rstoyanchev

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

@@ -71,8 +71,8 @@ public <T extends B> T webSessionManager(WebSessionManager sessionManager) {
 	}
 
 	@Override
-	public <T extends B> T sslInfo(SslInfo sslInfo) {
-		this.sslInfo = sslInfo;
+	public <T extends B> T sslInfo(@Nullable SslInfo info) {
+		this.sslInfo = info;
 		return self();
 	}
 

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

@@ -277,13 +277,13 @@ interface MockServerSpec<B extends MockServerSpec<B>> {
 		<T extends B> T webSessionManager(WebSessionManager sessionManager);
 
 		/**
-		 * Provide SSL session information and certificates for the mock server.
-		 * @param sslInfo the {@link SslInfo} to use
+		 * Set or reset SSL session information to assign to mock server requests.
+		 * @param info the {@link SslInfo} to use
 		 * @since 7.0
 		 * @see SslInfo#from(String)
 		 * @see SslInfo#from(String, java.security.cert.X509Certificate...)
 		 */
-		<T extends B> T sslInfo(SslInfo sslInfo);
+		<T extends B> T sslInfo(@Nullable SslInfo info);
 
 		/**
 		 * Shortcut for pre-packaged customizations to the mock server setup.

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

@@ -18,11 +18,13 @@
 
 import java.nio.charset.StandardCharsets;
 
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 import reactor.core.publisher.Mono;
 
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
+import org.springframework.http.server.reactive.SslInfo;
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.server.WebFilter;
 import org.springframework.web.server.WebFilterChain;
@@ -32,7 +34,6 @@
 
 /**
  * Tests for {@link AbstractMockServerSpec}.
- *
  * @author Rossen Stoyanchev
  */
 public class MockServerSpecTests {
@@ -43,30 +44,31 @@ public class MockServerSpecTests {
 	@Test
 	public void applyFiltersAfterConfigurerAdded() {
 
-		this.serverSpec.webFilter(new TestWebFilter("A"));
-
-		this.serverSpec.apply(new MockServerConfigurer() {
+		MockServerConfigurer configurer = new MockServerConfigurer() {
 
 			@Override
 			public void afterConfigureAdded(WebTestClient.MockServerSpec<?> spec) {
 				spec.webFilter(new TestWebFilter("B"));
 			}
-		});
+		};
 
-		this.serverSpec.build().get().uri("/")
+		this.serverSpec
+				.webFilter(new TestWebFilter("A"))
+				.apply(configurer)
+				.build()
+				.get().uri("/")
 				.exchange()
 				.expectBody(String.class)
-				.consumeWith(result -> assertThat(
-						result.getResponseBody()).contains("test-attribute=:A:B"));
+				.consumeWith(result -> {
+					String body = result.getResponseBody();
+					assertThat(body).contains("test-attribute=:A:B");
+				});
 	}
 
 	@Test
 	public void applyFiltersBeforeServerCreated() {
 
-		this.serverSpec.webFilter(new TestWebFilter("App-A"));
-		this.serverSpec.webFilter(new TestWebFilter("App-B"));
-
-		this.serverSpec.apply(new MockServerConfigurer() {
+		MockServerConfigurer configurer = new MockServerConfigurer() {
 
 			@Override
 			public void beforeServerCreated(WebHttpHandlerBuilder builder) {
@@ -75,21 +77,41 @@ public void beforeServerCreated(WebHttpHandlerBuilder builder) {
 					filters.add(1, new TestWebFilter("Fwk-B"));
 				});
 			}
-		});
-
-		this.serverSpec.build().get().uri("/")
-				.exchange()
+		};
+
+		this.serverSpec
+				.webFilter(new TestWebFilter("App-A"))
+				.webFilter(new TestWebFilter("App-B"))
+				.apply(configurer)
+				.build()
+				.get().uri("/").exchange()
 				.expectBody(String.class)
-				.consumeWith(result -> assertThat(
-						result.getResponseBody()).contains("test-attribute=:Fwk-A:Fwk-B:App-A:App-B"));
+				.consumeWith(result -> {
+					String body = result.getResponseBody();
+					assertThat(body).contains("test-attribute=:Fwk-A:Fwk-B:App-A:App-B");
+				});
+	}
+
+	@Test
+	void sslInfo() {
+		SslInfo info = SslInfo.from("123");
+		this.serverSpec.sslInfo(info).build().get().uri("/").exchange().expectStatus().isOk();
+		assertThat(this.serverSpec.getSavedSslInfo()).isSameAs(info);
 	}
 
 
 	private static class TestMockServerSpec extends AbstractMockServerSpec<TestMockServerSpec> {
 
+		private @Nullable SslInfo savedSslInfo;
+
+		public @Nullable SslInfo getSavedSslInfo() {
+			return this.savedSslInfo;
+		}
+
 		@Override
 		protected WebHttpHandlerBuilder initHttpHandlerBuilder() {
 			return WebHttpHandlerBuilder.webHandler(exchange -> {
+				this.savedSslInfo = exchange.getRequest().getSslInfo();
 				DefaultDataBufferFactory factory = DefaultDataBufferFactory.sharedInstance;
 				String text = exchange.getAttributes().toString();
 				DataBuffer buffer = factory.wrap(text.getBytes(StandardCharsets.UTF_8));
@@ -98,13 +120,8 @@ protected WebHttpHandlerBuilder initHttpHandlerBuilder() {
 		}
 	}
 
-	private static class TestWebFilter implements WebFilter {
-
-		private final String name;
 
-		TestWebFilter(String name) {
-			this.name = name;
-		}
+	private record TestWebFilter(String name) implements WebFilter {
 
 		@Override
 		public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {