Apply review feedback: use class reference and add unit tests

src/main/java/uk/ac/ox/ctl/SentryLoggingFilterConfiguration.java

@@ -5,22 +5,27 @@
 import io.sentry.SentryOptions;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver;
 
 @Configuration
 public class SentryLoggingFilterConfiguration {
 
 	private static final String EXCLUDED_LOGGER =
-			"org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver";
+			DefaultHandlerExceptionResolver.class.getName();
+
+	static SentryEvent filterEvent(SentryEvent event) {
+		if (EXCLUDED_LOGGER.equals(event.getLogger())) {
+			return null;
+		}
+		return event;
+	}
 
 	@Bean
 	public SentryOptions.BeforeSendCallback sentryBeforeSendCallback() {
 		return new SentryOptions.BeforeSendCallback() {
 			@Override
 			public SentryEvent execute(SentryEvent event, Hint hint) {
-				if (EXCLUDED_LOGGER.equals(event.getLogger())) {
-					return null;
-				}
-				return event;
+				return filterEvent(event);
 			}
 		};
 	}

src/test/java/uk/ac/ox/ctl/SentryLoggingFilterConfigurationTest.java

@@ -0,0 +1,41 @@
+package uk.ac.ox.ctl;
+
+import io.sentry.SentryEvent;
+import org.junit.jupiter.api.Test;
+import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+class SentryLoggingFilterConfigurationTest {
+
+	@Test
+	void filterEvent_shouldReturnNull_whenLoggerIsDefaultHandlerExceptionResolver() {
+		SentryEvent event = new SentryEvent();
+		event.setLogger(DefaultHandlerExceptionResolver.class.getName());
+
+		SentryEvent result = SentryLoggingFilterConfiguration.filterEvent(event);
+
+		assertNull(result, "Event should be filtered (null) when logger is DefaultHandlerExceptionResolver");
+	}
+
+	@Test
+	void filterEvent_shouldReturnEvent_whenLoggerIsNotExcluded() {
+		SentryEvent event = new SentryEvent();
+		event.setLogger("com.example.SomeOtherLogger");
+
+		SentryEvent result = SentryLoggingFilterConfiguration.filterEvent(event);
+
+		assertNotNull(result, "Event should not be filtered when logger is not excluded");
+	}
+
+	@Test
+	void filterEvent_shouldReturnEvent_whenLoggerIsNull() {
+		SentryEvent event = new SentryEvent();
+		event.setLogger(null);
+
+		SentryEvent result = SentryLoggingFilterConfiguration.filterEvent(event);
+
+		assertNotNull(result, "Event should not be filtered when logger is null");
+	}
+}