PO-234: Feature toggle add note (#255)

src/main/java/uk/gov/hmcts/opal/controllers/advice/GlobalExceptionHandler.java

@@ -0,0 +1,16 @@
+package uk.gov.hmcts.opal.controllers.advice;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import uk.gov.hmcts.opal.launchdarkly.FeatureDisabledException;
+
+@ControllerAdvice
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler(FeatureDisabledException.class)
+    public ResponseEntity<String> handleFeatureDisabledException(FeatureDisabledException ex) {
+        return ResponseEntity.status(HttpStatus.METHOD_NOT_ALLOWED).body(ex.getMessage());
+    }
+}

src/main/java/uk/gov/hmcts/opal/launchdarkly/FeatureDisabledException.java

@@ -0,0 +1,9 @@
+package uk.gov.hmcts.opal.launchdarkly;
+
+
+public class FeatureDisabledException extends RuntimeException {
+
+    public FeatureDisabledException(String message) {
+        super(message);
+    }
+}

src/main/java/uk/gov/hmcts/opal/launchdarkly/FeatureToggle.java

@@ -36,4 +36,19 @@
      * @return boolean value
      */
     boolean value() default true;
+
+    /**
+     * Indicates the default boolean value of feature toggle in case of failure to fetch the value from launchdarkly.
+     *
+     * @return boolean value
+     */
+    boolean defaultValue() default true;
+
+    /**
+     * Indicates the default Exception to throw when the feature is not enabled.
+     *
+     * @return boolean value
+     */
+    Class<? extends Throwable> throwException() default FeatureDisabledException.class;
+
 }

src/main/java/uk/gov/hmcts/opal/launchdarkly/FeatureToggleAspect.java

@@ -18,16 +18,30 @@ public class FeatureToggleAspect {
     @Around("execution(* *(*)) && @annotation(featureToggle)")
     public void checkFeatureEnabled(ProceedingJoinPoint joinPoint, FeatureToggle featureToggle) throws Throwable {
 
-        if (featureToggle.value() && featureToggleApi.isFeatureEnabled(featureToggle.feature())) {
+        if (featureToggle.value() && featureToggleApi.isFeatureEnabled(
+            featureToggle.feature(),
+            featureToggle.defaultValue()
+        )) {
             joinPoint.proceed();
-        } else if (!featureToggle.value() && !featureToggleApi.isFeatureEnabled(featureToggle.feature())) {
+        } else if (!featureToggle.value() && !featureToggleApi.isFeatureEnabled(
+            featureToggle.feature(),
+            featureToggle.defaultValue()
+        )) {
             joinPoint.proceed();
         } else {
-            log.warn(
+            String message = String.format(
                 "Feature %s is not enabled for method %s",
                 featureToggle.feature(),
                 joinPoint.getSignature().getName()
             );
+            log.warn(message);
+            // Check if an exception is specified in the annotation
+            if (featureToggle.throwException() != null) {
+                // Throw the specified exception
+                throw featureToggle.throwException()
+                    .getConstructor(String.class)
+                    .newInstance(message);
+            }
         }
     }
 }

src/main/java/uk/gov/hmcts/opal/service/proxy/NoteServiceProxy.java

@@ -5,6 +5,7 @@
 import org.springframework.stereotype.Service;
 import uk.gov.hmcts.opal.dto.NoteDto;
 import uk.gov.hmcts.opal.dto.search.NoteSearchDto;
+import uk.gov.hmcts.opal.launchdarkly.FeatureToggle;
 import uk.gov.hmcts.opal.service.DynamicConfigService;
 import uk.gov.hmcts.opal.service.NoteServiceInterface;
 import uk.gov.hmcts.opal.service.legacy.LegacyNoteService;
@@ -26,6 +27,7 @@ private NoteServiceInterface getCurrentModeService() {
     }
 
     @Override
+    @FeatureToggle(feature = "add-note", value = true)
     public NoteDto saveNote(NoteDto noteDto) {
         return getCurrentModeService().saveNote(noteDto);
     }

src/test/java/uk/gov/hmcts/opal/controllers/advice/GlobalExceptionHandlerTest.java

@@ -0,0 +1,38 @@
+package uk.gov.hmcts.opal.controllers.advice;
+
+import org.junit.jupiter.api.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.ContextConfiguration;
+import uk.gov.hmcts.opal.launchdarkly.FeatureDisabledException;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.when;
+
+@SpringBootTest
+@ContextConfiguration(classes = GlobalExceptionHandler.class)
+public class GlobalExceptionHandlerTest {
+
+    @Mock
+    private FeatureDisabledException exception;
+
+    @InjectMocks
+    private GlobalExceptionHandler globalExceptionHandler;
+
+    @Test
+    public void handleFeatureDisabledException_ReturnsMethodNotAllowed() {
+        // Arrange
+        String errorMessage = "Feature is disabled";
+        when(exception.getMessage()).thenReturn(errorMessage);
+
+        // Act
+        ResponseEntity<String> response = globalExceptionHandler.handleFeatureDisabledException(exception);
+
+        // Assert
+        assertEquals(HttpStatus.METHOD_NOT_ALLOWED, response.getStatusCode());
+        assertEquals(errorMessage, response.getBody());
+    }
+}

src/test/java/uk/gov/hmcts/opal/launchdarkly/FeatureDisabledExceptionTest.java

@@ -0,0 +1,20 @@
+package uk.gov.hmcts.opal.launchdarkly;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class FeatureDisabledExceptionTest {
+
+    @Test
+    public void testConstructor() {
+        // Arrange
+        String errorMessage = "Feature is disabled";
+
+        // Act
+        FeatureDisabledException exception = new FeatureDisabledException(errorMessage);
+
+        // Assert
+        assertEquals(errorMessage, exception.getMessage());
+    }
+}

src/test/java/uk/gov/hmcts/opal/launchdarkly/FeatureToggleAspectTest.java

@@ -14,6 +14,9 @@
 import org.springframework.boot.test.mock.mockito.MockBean;
 import org.springframework.test.context.junit.jupiter.SpringExtension;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.eq;
@@ -29,6 +32,7 @@
 class FeatureToggleAspectTest {
 
     private static final String NEW_FEATURE = "NEW_FEATURE";
+    private static final String EXCEPTION = "Feature NEW_FEATURE is not enabled for method myFeatureToggledMethod";
     @Autowired
     FeatureToggleAspect featureToggleAspect;
 
@@ -72,6 +76,24 @@ void shouldNotProceedToMethodInvocation_whenFeatureToggleIsDisabled(Boolean stat
         verify(proceedingJoinPoint, never()).proceed();
     }
 
+    @ParameterizedTest
+    @ValueSource(booleans = {true, false})
+    void shouldThrowException_whenFeatureToggleIsDisabled(Boolean state) {
+        when(featureToggle.value()).thenReturn(state);
+
+        when(featureToggle.throwException()).thenAnswer(invocation -> FeatureDisabledException.class);
+
+        givenToggle(NEW_FEATURE, !state);
+
+        FeatureDisabledException exception = assertThrows(
+            FeatureDisabledException.class,
+            () -> featureToggleAspect.checkFeatureEnabled(proceedingJoinPoint, featureToggle)
+        );
+
+        assertNotNull(exception);
+        assertEquals(EXCEPTION, exception.getMessage());
+    }
+
     private void givenToggle(String feature, boolean state) {
         when(ldClient.boolVariation(eq(feature), any(LDContext.class), anyBoolean()))
             .thenReturn(state);