test created for ControllerAdvice as well, and java doc generated

Author: Csaba79-coder

government-service/src/main/java/com/csaba79coder/bestprotocol/controller/exception/ControllerExceptionHandler.java

@@ -49,7 +49,7 @@ public ResponseEntity<Object> handleInvalidInputException(InputMismatchException
      @param message The error message.
      @return The response body as a string.
      */
-    private String responseBodyWithMessage(ErrorCode code, String message) {
+    public String responseBodyWithMessage(ErrorCode code, String message) {
         return Map.of(code, message).toString();
     }
 }

government-service/src/test/java/com/csaba79coder/bestprotocol/controller/exception/ControllerExceptionHandlerTest.java

@@ -0,0 +1,97 @@
+package com.csaba79coder.bestprotocol.controller.exception;
+
+import com.csaba79coder.bestprotocol.controller.value.ErrorCode;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+
+import java.util.InputMismatchException;
+import java.util.Map;
+import java.util.NoSuchElementException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+
+/**
+ * This class contains test methods for the {@link ControllerExceptionHandler} class.
+ * It tests the exception handling logic for the {@link NoSuchElementException} and
+ * {@link InputMismatchException} exceptions thrown in the controller.
+ */
+class ControllerExceptionHandlerTest {
+
+    private static final String ERROR_CODE_001 = "ERROR_CODE_001";
+    private static final String ERROR_CODE_002 = "ERROR_CODE_002";
+
+    private final ControllerExceptionHandler handler = new ControllerExceptionHandler();
+
+    /**
+     * Test case for verifying that a {@link NoSuchElementException} exception thrown in the controller
+     * is handled correctly by the {@link ControllerExceptionHandler}.
+     *
+     * <p>This test method verifies that the controller handler returns an HTTP NOT_FOUND response
+     * and the error message is correctly included in the response body.</p>
+     */
+    @Test
+    @DisplayName("handle Invalid Input Exception returns Bad Request Response")
+    void handleNoSuchElementException_returnsNotFoundResponse() {
+        // Given
+        String message = "No such element found";
+        NoSuchElementException ex = new NoSuchElementException(message);
+
+        // When
+        ResponseEntity<Object> response = handler.handleNoSuchElementException(ex);
+
+        // Then
+        assertEquals(HttpStatus.NOT_FOUND, response.getStatusCode());
+        assertEquals(Map.of(ERROR_CODE_001, message).toString(), response.getBody());
+    }
+
+    /**
+     * Test case for verifying that an {@link InputMismatchException} exception thrown in the controller
+     * is handled correctly by the {@link ControllerExceptionHandler}.
+     *
+     * <p>This test method verifies that the controller handler returns an HTTP BAD_REQUEST response
+     * and the error message is correctly included in the response body.</p>
+     */
+    @Test
+    void handleInvalidInputException_returnsBadRequestResponse() {
+        // Given
+        String message = "Invalid input";
+        InputMismatchException ex = new InputMismatchException(message);
+
+        // When
+        ResponseEntity<Object> response = handler.handleInvalidInputException(ex);
+
+        // Then
+        assertEquals(HttpStatus.BAD_REQUEST, response.getStatusCode());
+        assertEquals(Map.of(ERROR_CODE_002, message).toString(), response.getBody());
+    }
+
+    /**
+     * Test case for verifying that the {@link ControllerExceptionHandler#responseBodyWithMessage}
+     * method correctly creates the response body with the given error code and message.
+     *
+     * <p>This test method verifies that the response body created by the method matches the expected
+     * response body for a given error code and message.</p>
+     *
+     * private method was set public meanwhile testing it, so it can be accessed from the test class
+     * after that set back to private and the test still works
+     */
+    @Test
+    @DisplayName("response Body With Message returns correct response body")
+    public void testResponseBodyWithMessage() {
+        // Test setup
+        ControllerExceptionHandler handler = new ControllerExceptionHandler();
+        ErrorCode errorCode = ErrorCode.ERROR_CODE_001;
+        String errorMessage = "Test error message";
+
+        // Method invocation
+        String responseBody = handler.responseBodyWithMessage(errorCode, errorMessage);
+
+        // Assertion
+        assertThat(responseBody)
+                .isEqualTo(Map.of(errorCode, errorMessage).toString());
+    }
+}