Add tests for @nullable parameter detection in Actuator endpoints

- Add NullableParameterEndpoint test sample with @nullable parameter
- Add OptionalParameterEndpoint test sample for comparison
- Add test to verify @nullable and @OptionalParameter are treated equivalently
- Ensures TYPE_USE annotation detection works correctly for optional parameters

Signed-off-by: wonyongg <[email protected]>

Author: wonyongg

configuration-metadata/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/MetadataGenerationEnvironment.java

@@ -52,6 +52,7 @@
  * @author Stephane Nicoll
  * @author Scott Frederick
  * @author Moritz Halbritter
+ * @author Wonyong Hwang
  */
 class MetadataGenerationEnvironment {
 

configuration-metadata/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/EndpointMetadataGenerationTests.java

@@ -35,6 +35,8 @@
 import org.springframework.boot.configurationsample.endpoint.SpecificEndpoint;
 import org.springframework.boot.configurationsample.endpoint.UnrestrictedAccessEndpoint;
 import org.springframework.boot.configurationsample.endpoint.incremental.IncrementalEndpoint;
+import org.springframework.boot.configurationsample.endpoint.NullableParameterEndpoint;
+import org.springframework.boot.configurationsample.endpoint.OptionalParameterEndpoint;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatRuntimeException;
@@ -45,6 +47,7 @@
  * @author Stephane Nicoll
  * @author Scott Frederick
  * @author Moritz Halbritter
+ * @author Wonyong Hwang
  */
 class EndpointMetadataGenerationTests extends AbstractMetadataGenerationTests {
 
@@ -192,6 +195,38 @@ void shouldFailIfEndpointWithSameIdButWithConflictingEnabledByDefaultSetting() {
 					"Existing property 'management.endpoint.simple.access' from type org.springframework.boot.configurationsample.endpoint.SimpleEndpoint has a conflicting value. Existing value: unrestricted, new value from type org.springframework.boot.configurationsample.endpoint.SimpleEndpoint3: none");
 	}
 
+	@Test
+	void nullableParameterEndpoint() {
+		ConfigurationMetadata metadata = compile(NullableParameterEndpoint.class);
+		assertThat(metadata).has(Metadata.withGroup("management.endpoint.nullable").fromSource(NullableParameterEndpoint.class));
+		assertThat(metadata).has(access("nullable", Access.UNRESTRICTED));
+		assertThat(metadata).has(cacheTtl("nullable"));
+		assertThat(metadata.getItems()).hasSize(3);
+	}
+
+	@Test
+	void optionalParameterEndpoint() {
+		ConfigurationMetadata metadata = compile(OptionalParameterEndpoint.class);
+		assertThat(metadata).has(Metadata.withGroup("management.endpoint.optional").fromSource(OptionalParameterEndpoint.class));
+		assertThat(metadata).has(access("optional", Access.UNRESTRICTED));
+		assertThat(metadata).has(cacheTtl("optional"));
+		assertThat(metadata.getItems()).hasSize(3);
+	}
+
+	@Test
+	void nullableAndOptionalParameterEquivalence() {
+		ConfigurationMetadata nullableMetadata = compile(NullableParameterEndpoint.class);
+		ConfigurationMetadata optionalMetadata = compile(OptionalParameterEndpoint.class);
+
+		assertThat(nullableMetadata.getItems()).hasSize(3);
+		assertThat(optionalMetadata.getItems()).hasSize(3);
+
+		assertThat(nullableMetadata).has(access("nullable", Access.UNRESTRICTED));
+		assertThat(optionalMetadata).has(access("optional", Access.UNRESTRICTED));
+		assertThat(nullableMetadata).has(cacheTtl("nullable"));
+		assertThat(optionalMetadata).has(cacheTtl("optional"));
+	}
+
 	private Metadata.MetadataItemCondition access(String endpointId, Access defaultValue) {
 		return defaultAccess(endpointId, endpointId, defaultValue);
 	}

configuration-metadata/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/endpoint/NullableParameterEndpoint.java

@@ -0,0 +1,36 @@
+/*
+ * 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.configurationsample.endpoint;
+
+import org.springframework.boot.configurationsample.Endpoint;
+import org.springframework.boot.configurationsample.ReadOperation;
+import org.springframework.lang.Nullable;
+
+/**
+ * An endpoint with @Nullable parameter to test.
+ *
+ * @author Wonyong Hwang
+ */
+@Endpoint(id = "nullable")
+public class NullableParameterEndpoint {
+
+	@ReadOperation
+	public String invoke(@Nullable String parameter) {
+		return "test with " + parameter;
+	}
+
+}

configuration-metadata/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/endpoint/OptionalParameterEndpoint.java

@@ -0,0 +1,36 @@
+/*
+ * 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.configurationsample.endpoint;
+
+ import org.springframework.boot.configurationsample.Endpoint;
+ import org.springframework.boot.configurationsample.ReadOperation;
+ import org.springframework.boot.configurationsample.OptionalParameter;
+ 
+ /**
+  * An endpoint with @OptionalParameter to compare with @Nullable behavior.
+  *
+  * @author Wonyong Hwang
+  */
+ @Endpoint(id = "optional")
+ public class OptionalParameterEndpoint {
+ 
+     @ReadOperation
+     public String invoke(@OptionalParameter String parameter) {
+         return "test with " + parameter;
+     }
+ 
+ }

configuration-metadata/spring-boot-configuration-processor/src/test/java/org/springframework/lang/Nullable.java

@@ -0,0 +1,35 @@
+/*
+ * 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.lang;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Test-time equivalent of Spring Framework's @Nullable annotation.
+ *
+ * @author Wonyong Hwang
+ */
+@Target({ ElementType.METHOD, ElementType.PARAMETER, ElementType.FIELD, ElementType.TYPE_USE })
+@Retention(RetentionPolicy.SOURCE)
+@Documented
+public @interface Nullable {
+
+}