Add integration test for compatibility between @HxRequest and @respon…

…sebody

Relates to #42

src/test/java/io/github/wimdeblauwe/hsbt/mvc/HtmxHandlerInterceptorIT.java

@@ -0,0 +1,35 @@
+package io.github.wimdeblauwe.hsbt.mvc;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.boot.test.web.server.LocalServerPort;
+import org.springframework.http.ResponseEntity;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+@EnableAutoConfiguration(exclude = {SecurityAutoConfiguration.class}) // Security is on by default
+@MockBean(PartialsController.TodoRepository.class)
+class HtmxHandlerInterceptorIT {
+
+    @Autowired
+    protected TestRestTemplate restTemplate;
+
+    @LocalServerPort
+    protected int port;
+
+    @Test
+    public void testHeaderIsSetOnResponseIfHxTriggerIsPresent() {
+        final ResponseEntity<String> response
+                = restTemplate.getForEntity("http://localhost:" + port + "/with-trigger", String.class);
+
+        // Passes if preHandle is used, fails if postHandle is used (HtmxHandlerInterceptor)
+        assertThat(response.getHeaders().get("HX-Trigger")).isNotNull();
+        assertThat(response.getHeaders().get("HX-Trigger")).asList().containsOnly("eventTriggered");
+    }
+}