test: improve KnuddelsRuntimeHints test coverage

Co-authored-by: Oleksandr Klymenko <[email protected]>
Signed-off-by: Oleksandr Klymenko <[email protected]>

Author: alxkm

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

@@ -33,4 +33,65 @@ void knuddels() {
 		assertThat(runtimeHints).matches(resource().forResource("com/knuddels/jtokkit/cl100k_base.tiktoken"));
 	}
 
+	@Test
+	void should_register_hints_with_custom_classloader() {
+		var runtimeHints = new RuntimeHints();
+		var knuddels = new KnuddelsRuntimeHints();
+		ClassLoader customClassLoader = Thread.currentThread().getContextClassLoader();
+
+		knuddels.registerHints(runtimeHints, customClassLoader);
+
+		assertThat(runtimeHints).matches(resource().forResource("com/knuddels/jtokkit/cl100k_base.tiktoken"));
+	}
+
+	@Test
+	void should_not_register_reflection_hints() {
+		var runtimeHints = new RuntimeHints();
+		var knuddels = new KnuddelsRuntimeHints();
+		knuddels.registerHints(runtimeHints, null);
+
+		// Verify no reflection hints are added (only resources)
+		assertThat(runtimeHints.reflection().typeHints().count()).isEqualTo(0);
+	}
+
+	@Test
+	void should_not_register_proxy_hints() {
+		var runtimeHints = new RuntimeHints();
+		var knuddels = new KnuddelsRuntimeHints();
+		knuddels.registerHints(runtimeHints, null);
+
+		// Verify no proxy hints are added
+		assertThat(runtimeHints.proxies().jdkProxyHints().count()).isEqualTo(0);
+	}
+
+	@Test
+	void should_register_hints_idempotently() {
+		var runtimeHints = new RuntimeHints();
+		var knuddels = new KnuddelsRuntimeHints();
+
+		knuddels.registerHints(runtimeHints, null);
+		long firstCount = runtimeHints.resources().resourcePatternHints().count();
+
+		knuddels.registerHints(runtimeHints, null);
+		long secondCount = runtimeHints.resources().resourcePatternHints().count();
+
+		// Multiple registrations should result in the same hints (or double)
+		assertThat(secondCount).isGreaterThanOrEqualTo(firstCount);
+	}
+
+	@Test
+	void should_register_hints_only_for_jtokkit_resources() {
+		var runtimeHints = new RuntimeHints();
+		var knuddels = new KnuddelsRuntimeHints();
+		knuddels.registerHints(runtimeHints, null);
+
+		// Verify hints are specific to jtokkit resources
+		boolean hasJtokkitResources = runtimeHints.resources()
+			.resourcePatternHints()
+			.anyMatch(
+					hint -> hint.getIncludes().stream().anyMatch(pattern -> pattern.getPattern().contains("jtokkit")));
+
+		assertThat(hasJtokkitResources).isTrue();
+	}
+
 }