Simplify validation errors' output

4 files changed, 70 insertions, 16 deletions

diff --git a/src/main/java/org/luxons/sevenwonders/errors/ErrorType.java b/src/main/java/org/luxons/sevenwonders/errors/ErrorType.java
index 71df185f..a4a0f631 100644
--- a/src/main/java/org/luxons/sevenwonders/errors/ErrorType.java
+++ b/src/main/java/org/luxons/sevenwonders/errors/ErrorType.java
@@ -1,6 +1,6 @@
 package org.luxons.sevenwonders.errors;
 
-public enum ErrorType {
+enum ErrorType {
     USER,
     VALIDATION,
     INTERNAL
diff --git a/src/main/java/org/luxons/sevenwonders/errors/ExceptionHandler.java b/src/main/java/org/luxons/sevenwonders/errors/ExceptionHandler.java
index 9e26cbe3..26a84ab2 100644
--- a/src/main/java/org/luxons/sevenwonders/errors/ExceptionHandler.java
+++ b/src/main/java/org/luxons/sevenwonders/errors/ExceptionHandler.java
@@ -11,6 +11,7 @@ import org.springframework.messaging.converter.MessageConversionException;
 import org.springframework.messaging.handler.annotation.MessageExceptionHandler;
 import org.springframework.messaging.handler.annotation.support.MethodArgumentNotValidException;
 import org.springframework.messaging.simp.annotation.SendToUser;
+import org.springframework.validation.BindingResult;
 import org.springframework.validation.ObjectError;
 import org.springframework.web.bind.annotation.ControllerAdvice;
 
@@ -19,9 +20,9 @@ public class ExceptionHandler {
 
     private static final Logger logger = LoggerFactory.getLogger(ExceptionHandler.class);
 
-    private static final String ERROR_CODE_VALIDATION = "VALIDATION_ERROR";
+    private static final String ERROR_CODE_VALIDATION = "INVALID_DATA";
 
-    private static final String ERROR_CODE_CONVERSION = "MESSAGE_FORMAT_ERROR";
+    private static final String ERROR_CODE_CONVERSION = "INVALID_MESSAGE_FORMAT";
 
     private static final String ERROR_MSG_VALIDATION = "Invalid input data";
 
@@ -36,24 +37,28 @@ public class ExceptionHandler {
 
     @MessageExceptionHandler
     @SendToUser("/queue/errors")
-    private UIError handleValidationError(MethodArgumentNotValidException exception) {
+    public UIError handleValidationError(MethodArgumentNotValidException exception) {
         logger.error("Invalid input", exception);
-        List<ObjectError> errors = exception.getBindingResult().getAllErrors();
         UIError uiError = new UIError(ERROR_CODE_VALIDATION, ERROR_MSG_VALIDATION, ErrorType.VALIDATION);
-        uiError.setValidationErrors(errors);
+
+        BindingResult result = exception.getBindingResult();
+        if (result != null) {
+            List<ObjectError> errors = exception.getBindingResult().getAllErrors();
+            uiError.addDetails(errors);
+        }
         return uiError;
     }
 
     @MessageExceptionHandler
     @SendToUser("/queue/errors")
-    private UIError handleConversionError(MessageConversionException exception) {
+    public UIError handleConversionError(MessageConversionException exception) {
         logger.error("Error interpreting the message", exception);
         return new UIError(ERROR_CODE_CONVERSION, ERROR_MSG_CONVERSION, ErrorType.VALIDATION);
     }
 
     @MessageExceptionHandler
     @SendToUser("/queue/errors")
-    private UIError handleGenericUserError(UserInputException exception) {
+    public UIError handleGenericUserError(UserInputException exception) {
         logger.error("Incorrect user input: " + exception.getMessage());
         String messageKey = exception.getMessageResourceKey();
         String message = messageSource.getMessage(messageKey, exception.getParams(), messageKey, Locale.US);
@@ -62,14 +67,14 @@ public class ExceptionHandler {
 
     @MessageExceptionHandler
     @SendToUser("/queue/errors")
-    private UIError handleApiError(ApiMisuseException exception) {
+    public UIError handleApiError(ApiMisuseException exception) {
         logger.error("Invalid API input", exception);
         return new UIError(exception.getClass().getSimpleName(), exception.getMessage(), ErrorType.INTERNAL);
     }
 
     @MessageExceptionHandler
     @SendToUser("/queue/errors")
-    private UIError handleUnexpectedInternalError(Throwable exception) {
+    public UIError handleUnexpectedInternalError(Throwable exception) {
         logger.error("Uncaught exception thrown during message handling", exception);
         return new UIError(exception.getClass().getSimpleName(), exception.getMessage(), ErrorType.INTERNAL);
     }
diff --git a/src/main/java/org/luxons/sevenwonders/errors/UIError.java b/src/main/java/org/luxons/sevenwonders/errors/UIError.java
index 67802f22..ee5fcbe0 100644
--- a/src/main/java/org/luxons/sevenwonders/errors/UIError.java
+++ b/src/main/java/org/luxons/sevenwonders/errors/UIError.java
@@ -1,7 +1,9 @@
 package org.luxons.sevenwonders.errors;
 
+import java.util.ArrayList;
 import java.util.List;
 
+import org.springframework.validation.FieldError;
 import org.springframework.validation.ObjectError;
 
 public class UIError {
@@ -12,9 +14,9 @@ public class UIError {
 
     private final ErrorType type;
 
-    private List<ObjectError> validationErrors;
+    private List<UIErrorDetail> details = new ArrayList<>();
 
-    public UIError(String code, String message, ErrorType type) {
+    UIError(String code, String message, ErrorType type) {
         this.code = code;
         this.message = message;
         this.type = type;
@@ -32,11 +34,21 @@ public class UIError {
         return type;
     }
 
-    public List<ObjectError> getValidationErrors() {
-        return validationErrors;
+    public List<UIErrorDetail> getDetails() {
+        return details;
     }
 
-    public void setValidationErrors(List<ObjectError> validationErrors) {
-        this.validationErrors = validationErrors;
+    void addDetails(List<ObjectError> objectErrors) {
+        for (ObjectError objectError : objectErrors) {
+            this.details.add(convertError(objectError));
+        }
+    }
+
+    private UIErrorDetail convertError(ObjectError objectError) {
+        if (objectError instanceof FieldError) {
+            return new UIErrorDetail((FieldError)objectError);
+        } else {
+            return new UIErrorDetail(objectError);
+        }
     }
 }
diff --git a/src/main/java/org/luxons/sevenwonders/errors/UIErrorDetail.java b/src/main/java/org/luxons/sevenwonders/errors/UIErrorDetail.java
new file mode 100644
index 00000000..dc4250bb
--- /dev/null
+++ b/src/main/java/org/luxons/sevenwonders/errors/UIErrorDetail.java
@@ -0,0 +1,37 @@
+package org.luxons.sevenwonders.errors;
+
+import org.springframework.validation.FieldError;
+import org.springframework.validation.ObjectError;
+
+class UIErrorDetail {
+
+    private final Object rejectedValue;
+
+    private final String path;
+
+    private final String message;
+
+    UIErrorDetail(FieldError error) {
+        rejectedValue = error.getRejectedValue();
+        path = error.getObjectName() + '.' + error.getField();
+        message = "Invalid value for field '" + error.getField() + "': " + error.getDefaultMessage();
+    }
+
+    UIErrorDetail(ObjectError error) {
+        rejectedValue = null;
+        path = error.getObjectName();
+        message = "Invalid value for object '" + error.getObjectName() + "': " + error.getDefaultMessage();
+    }
+
+    public Object getRejectedValue() {
+        return rejectedValue;
+    }
+
+    public String getPath() {
+        return path;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+}