Added test for controller exception handler

build.gradle

@@ -93,6 +93,9 @@ dependencies {
     // https://mvnrepository.com/artifact/org.mockito/mockito-core
     testImplementation group: 'org.mockito', name: 'mockito-core', version: '3.5.13'
 
+    // https://mvnrepository.com/artifact/org.mockito/mockito-junit-jupiter
+    testImplementation group: 'org.mockito', name: 'mockito-junit-jupiter', version: '3.5.13'
+
     // https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter
     testImplementation group: 'org.junit.jupiter', name: 'junit-jupiter', version: '5.7.0'
 

src/test/java/org/sasanlabs/controller/exception/ControllerExceptionHandlerTest.java

@@ -0,0 +1,64 @@
+package org.sasanlabs.controller.exception;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.sasanlabs.internal.utility.MessageBundle;
+import org.sasanlabs.service.exception.ExceptionStatusCodeEnum;
+import org.sasanlabs.service.exception.ServiceApplicationException;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.context.request.WebRequest;
+
+@ExtendWith(MockitoExtension.class)
+class ControllerExceptionHandlerTest {
+
+    @Mock private MessageBundle messageBundle;
+
+    @Mock private WebRequest webRequest;
+
+    @InjectMocks private ControllerExceptionHandler controllerExceptionHandler;
+
+    @Test
+    void shouldHandleControllerExceptions() {
+        // Arrange
+        when(messageBundle.getString(any(), any())).thenReturn("Exception occurred");
+        ServiceApplicationException serviceApplicationException =
+                new ServiceApplicationException(
+                        ExceptionStatusCodeEnum.SYSTEM_ERROR, new NullPointerException("ex"));
+
+        // Act
+        ResponseEntity<String> responseEntity =
+                controllerExceptionHandler.handleControllerExceptions(
+                        new ControllerException(serviceApplicationException), webRequest);
+
+        // Assert
+        assertEquals(HttpStatus.INTERNAL_SERVER_ERROR, responseEntity.getStatusCode());
+        assertEquals("Exception occurred", responseEntity.getBody());
+        verify(messageBundle).getString(any(), any());
+    }
+
+    @Test
+    void shouldHandleExceptions() {
+        // Arrange
+        when(messageBundle.getString(any(), any())).thenReturn("IO exception occurred");
+
+        // Act
+        ResponseEntity<String> responseEntity =
+                controllerExceptionHandler.handleExceptions(
+                        new IOException("IO operation failed"), webRequest);
+
+        // Assert
+        assertEquals(HttpStatus.INTERNAL_SERVER_ERROR, responseEntity.getStatusCode());
+        assertEquals("IO exception occurred", responseEntity.getBody());
+        verify(messageBundle).getString(any(), any());
+    }
+}