test: Add comprehensive test coverage for SpringAI core runtime hints registration

spring-ai-model/src/test/java/org/springframework/ai/aot/SpringAiCoreRuntimeHintsTest.java

@@ -21,8 +21,13 @@
 import org.springframework.ai.tool.ToolCallback;
 import org.springframework.ai.tool.definition.ToolDefinition;
 import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.TypeReference;
+
+import java.util.HashSet;
+import java.util.Set;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
 import static org.springframework.aot.hint.predicate.RuntimeHintsPredicates.reflection;
 import static org.springframework.aot.hint.predicate.RuntimeHintsPredicates.resource;
 
@@ -42,4 +47,97 @@ void core() {
 		assertThat(runtimeHints).matches(reflection().onType(ToolDefinition.class));
 	}
 
+	@Test
+	void registerHintsWithNullClassLoader() {
+		var runtimeHints = new RuntimeHints();
+		var springAiCore = new SpringAiCoreRuntimeHints();
+
+		// Should not throw exception with null ClassLoader
+		assertThatCode(() -> springAiCore.registerHints(runtimeHints, null)).doesNotThrowAnyException();
+	}
+
+	@Test
+	void verifyEmbeddingResourceIsRegistered() {
+		var runtimeHints = new RuntimeHints();
+		var springAiCore = new SpringAiCoreRuntimeHints();
+		springAiCore.registerHints(runtimeHints, null);
+
+		// Verify the specific embedding properties file is registered
+		assertThat(runtimeHints).matches(resource().forResource("embedding/embedding-model-dimensions.properties"));
+	}
+
+	@Test
+	void verifyToolReflectionHintsAreRegistered() {
+		var runtimeHints = new RuntimeHints();
+		var springAiCore = new SpringAiCoreRuntimeHints();
+		springAiCore.registerHints(runtimeHints, null);
+
+		Set<TypeReference> registeredTypes = new HashSet<>();
+		runtimeHints.reflection().typeHints().forEach(typeHint -> registeredTypes.add(typeHint.getType()));
+
+		// Verify core tool classes are registered
+		assertThat(registeredTypes.contains(TypeReference.of(ToolCallback.class))).isTrue();
+		assertThat(registeredTypes.contains(TypeReference.of(ToolDefinition.class))).isTrue();
+	}
+
+	@Test
+	void verifyResourceAndReflectionHintsSeparately() {
+		var runtimeHints = new RuntimeHints();
+		var springAiCore = new SpringAiCoreRuntimeHints();
+		springAiCore.registerHints(runtimeHints, null);
+
+		// Test resource hints
+		assertThat(runtimeHints).matches(resource().forResource("embedding/embedding-model-dimensions.properties"));
+
+		// Test reflection hints
+		assertThat(runtimeHints).matches(reflection().onType(ToolCallback.class));
+		assertThat(runtimeHints).matches(reflection().onType(ToolDefinition.class));
+	}
+
+	@Test
+	void verifyMultipleRegistrationCallsAreIdempotent() {
+		var runtimeHints1 = new RuntimeHints();
+		var runtimeHints2 = new RuntimeHints();
+		var springAiCore = new SpringAiCoreRuntimeHints();
+
+		// Register hints on two separate RuntimeHints instances
+		springAiCore.registerHints(runtimeHints1, null);
+		springAiCore.registerHints(runtimeHints2, null);
+
+		// Both should have the same hints registered
+		assertThat(runtimeHints1).matches(resource().forResource("embedding/embedding-model-dimensions.properties"));
+		assertThat(runtimeHints2).matches(resource().forResource("embedding/embedding-model-dimensions.properties"));
+
+		assertThat(runtimeHints1).matches(reflection().onType(ToolCallback.class));
+		assertThat(runtimeHints2).matches(reflection().onType(ToolCallback.class));
+	}
+
+	@Test
+	void verifyResourceHintsForIncorrectPaths() {
+		var runtimeHints = new RuntimeHints();
+		var springAiCore = new SpringAiCoreRuntimeHints();
+		springAiCore.registerHints(runtimeHints, null);
+
+		// Verify the exact resource path is registered
+		assertThat(runtimeHints).matches(resource().forResource("embedding/embedding-model-dimensions.properties"));
+
+		// Verify that similar but incorrect paths are not matched
+		assertThat(runtimeHints).doesNotMatch(resource().forResource("embedding-model-dimensions.properties"));
+		assertThat(runtimeHints).doesNotMatch(resource().forResource("embedding/model-dimensions.properties"));
+	}
+
+	@Test
+	void ensureBothResourceAndReflectionHintsArePresent() {
+		var runtimeHints = new RuntimeHints();
+		var springAiCore = new SpringAiCoreRuntimeHints();
+		springAiCore.registerHints(runtimeHints, null);
+
+		// Ensure both resource and reflection hints are registered
+		boolean hasResourceHints = runtimeHints.resources() != null;
+		boolean hasReflectionHints = runtimeHints.reflection().typeHints().spliterator().estimateSize() > 0;
+
+		assertThat(hasResourceHints).isTrue();
+		assertThat(hasReflectionHints).isTrue();
+	}
+
 }