feature: reconcile tests with the records, 404 and RestClient changes

The test suite was written in parallel against the pre-modernization API:
- Topic accessors are record components now (getId -> id)
- getTopicWithId returns Optional and an unknown id is a 404, not a 500,
  so the placeholder assertions and their @disabled twins collapse into one
- the RestTemplate bean is a RestClient bean

Co-Authored-By: alex.vyshetsky <alex.vyshetsky@cognition.ai>

Author: devin-ai-integration[bot]

src/test/java/hello/ApplicationContextLoadTest.java

@@ -5,7 +5,7 @@
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.context.ApplicationContext;
 import org.springframework.jdbc.core.JdbcTemplate;
-import org.springframework.web.client.RestTemplate;
+import org.springframework.web.client.RestClient;
 
 import hello.controller.GreetingController;
 import hello.controller.HelloController;
@@ -36,7 +36,7 @@ void exposesTheExpectedBeans() {
         assertThat(context.getBean(TopicController.class)).isNotNull();
         assertThat(context.getBean(HelloController.class)).isNotNull();
         assertThat(context.getBean(GreetingController.class)).isNotNull();
-        assertThat(context.getBean(RestTemplate.class)).isNotNull();
+        assertThat(context.getBean(RestClient.class)).isNotNull();
         assertThat(context.getBean(JdbcTemplate.class)).isNotNull();
     }
 

src/test/java/hello/controller/TopicNotFoundStatusTest.java

@@ -1,6 +1,5 @@
 package hello.controller;
 
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
@@ -15,10 +14,8 @@
  * MockMvc rethrows unhandled exceptions instead of running the error dispatch, so this one case is
  * driven over a real connection.
  *
- * <p>{@code TopicService.getTopicWithId} calls {@code Optional.get()} on a miss, which throws
- * {@link java.util.NoSuchElementException} and surfaces as HTTP 500. That is asserted here as the
- * <em>current</em> behaviour; the disabled test below is the replacement for when a parallel change
- * turns the miss into a proper 404.
+ * <p>{@code TopicService.getTopicWithId} returns an empty {@link java.util.Optional} on a miss, which
+ * the controller translates into a 404.
  */
 @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
 class TopicNotFoundStatusTest {
@@ -27,15 +24,7 @@ class TopicNotFoundStatusTest {
     private TestRestTemplate restTemplate;
 
     @Test
-    void unknownTopicIdCurrentlyReturnsInternalServerError() {
-        ResponseEntity<String> response = restTemplate.getForEntity("/topic/does-not-exist", String.class);
-
-        assertThat(response.getStatusCode()).isEqualTo(HttpStatus.INTERNAL_SERVER_ERROR);
-    }
-
-    @Test
-    @Disabled("Enable, and delete unknownTopicIdCurrentlyReturnsInternalServerError, once an unknown id is a 404")
-    void unknownTopicIdShouldReturnNotFound() {
+    void unknownTopicIdReturnsNotFound() {
         ResponseEntity<String> response = restTemplate.getForEntity("/topic/does-not-exist", String.class);
 
         assertThat(response.getStatusCode()).isEqualTo(HttpStatus.NOT_FOUND);

src/test/java/hello/service/TopicServiceTest.java

@@ -37,7 +37,7 @@ void createFreshService() {
      * records only has to touch one line in this class.
      */
     private static List<String> idsOf(List<Topic> topics) {
-        return topics.stream().map(Topic::getId).collect(Collectors.toList());
+        return topics.stream().map(Topic::id).collect(Collectors.toList());
     }
 
     @Test
@@ -48,26 +48,16 @@ void seedsThreeTopics() {
 
     @Test
     void getTopicWithIdReturnsTheMatchingTopic() {
-        Topic topic = topicService.getTopicWithId("java");
+        Topic topic = topicService.getTopicWithId("java").orElseThrow();
 
         assertThat(idsOf(List.of(topic))).containsExactly("java");
-        assertThat(topic.getSubjectName()).isEqualTo("Core Java");
+        assertThat(topic.subjectName()).isEqualTo("Core Java");
     }
 
     @Test
-    void getTopicWithIdThrowsForAnUnknownId() {
-        // Current behaviour: Optional.get() on an empty Optional. Over HTTP this surfaces as a 500.
-        assertThatThrownBy(() -> topicService.getTopicWithId("does-not-exist"))
-                .isInstanceOf(NoSuchElementException.class);
-    }
-
-    @Test
-    @Disabled("Enable together with the parallel change that makes an unknown id a proper 404")
-    void getTopicWithIdShouldReportAMissingTopicWithoutThrowing() {
-        // Replacement for getTopicWithIdThrowsForAnUnknownId once the service returns an empty
-        // Optional (or the controller translates the miss into HTTP 404).
-        assertThatCode(() -> topicService.getTopicWithId("does-not-exist"))
-                .doesNotThrowAnyException();
+    void getTopicWithIdReportsAMissingTopicWithoutThrowing() {
+        assertThatCode(() -> topicService.getTopicWithId("does-not-exist")).doesNotThrowAnyException();
+        assertThat(topicService.getTopicWithId("does-not-exist")).isEmpty();
     }
 
     @Test
@@ -83,7 +73,7 @@ void updateTopicReplacesTheTopicInPlace() {
 
         List<Topic> topics = topicService.getAllTopics();
         assertThat(idsOf(topics)).containsExactly("spring", "java", "javascript");
-        assertThat(topics.get(1).getSubjectName()).isEqualTo("Updated Java");
+        assertThat(topics.get(1).subjectName()).isEqualTo("Updated Java");
     }
 
     @Test