Add predicates for Serialization hints

Closes gh-28772

Author: snicoll

spring-core/src/main/java/org/springframework/aot/hint/RuntimeHintsPredicates.java

@@ -37,6 +37,8 @@ public abstract class RuntimeHintsPredicates {
 
 	private static final ResourceHintsPredicates resource = new ResourceHintsPredicates();
 
+	private static final SerializationHintsPredicates serialization = new SerializationHintsPredicates();
+
 	private static final ProxyHintsPredicates proxies = new ProxyHintsPredicates();
 
 
@@ -59,6 +61,14 @@ public static ResourceHintsPredicates resource() {
 		return resource;
 	}
 
+	/**
+	 * Return a predicate generator for {@link SerializationHints serialization hints}.
+	 * @return the predicate generator
+	 */
+	public static SerializationHintsPredicates serialization() {
+		return serialization;
+	}
+
 	/**
 	 * Return a predicate generator for {@link ProxyHints proxy hints}.
 	 * @return the predicate generator

spring-core/src/main/java/org/springframework/aot/hint/SerializationHintsPredicates.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2002-2022 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.aot.hint;
+
+import java.util.function.Predicate;
+
+import org.springframework.util.Assert;
+
+/**
+ * Generator of {@link SerializationHints} predicates, testing whether the
+ * given hints match the expected behavior for serialization.
+ *
+ * @author Stephane Nicoll
+ * @since 6.0
+ */
+public class SerializationHintsPredicates {
+
+	SerializationHintsPredicates() {
+	}
+
+	/**
+	 * Return a predicate that checks whether a {@link SerializationHints
+	 * serialization hint} is registered for the given type.
+	 * @param type the type to check
+	 * @return the {@link RuntimeHints} predicate
+	 * @see java.lang.reflect.Proxy
+	 */
+	public Predicate<RuntimeHints> onType(Class<?> type) {
+		Assert.notNull(type, "'type' should not be null");
+		return onType(TypeReference.of(type));
+	}
+
+	/**
+	 * Return a predicate that checks whether a {@link SerializationHints
+	 * serialization hint} is registered for the given type reference.
+	 * @param typeReference the type to check
+	 * @return the {@link RuntimeHints} predicate
+	 * @see java.lang.reflect.Proxy
+	 */
+	public Predicate<RuntimeHints> onType(TypeReference typeReference) {
+		Assert.notNull(typeReference, "'typeReference' should not be null");
+		return hints -> hints.serialization().javaSerialization().anyMatch(
+				hint -> hint.getType().equals(typeReference));
+	}
+
+}

spring-core/src/test/java/org/springframework/aot/hint/SerializationHintsPredicatesTests.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2002-2022 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.aot.hint;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link SerializationHintsPredicates}.
+ *
+ * @author Stephane Nicoll
+ */
+class SerializationHintsPredicatesTests {
+
+	private final SerializationHintsPredicates serialization = new SerializationHintsPredicates();
+
+	private final RuntimeHints runtimeHints = new RuntimeHints();
+
+	@Test
+	void shouldMatchRegisteredClass() {
+		runtimeHints.serialization().registerType(String.class);
+		assertThat(serialization.onType(String.class).test(runtimeHints)).isTrue();
+	}
+
+	@Test
+	void shouldMatchRegisteredTypeReference() {
+		runtimeHints.serialization().registerType(TypeReference.of(String.class));
+		assertThat(serialization.onType(String.class).test(runtimeHints)).isTrue();
+	}
+
+	@Test
+	void shouldNotMatchUnregisteredType() {
+		runtimeHints.serialization().registerType(Integer.class);
+		assertThat(serialization.onType(Long.class).test(runtimeHints)).isFalse();
+	}
+
+}