Add Error method to laravel like error and add prefix method to Valid…

…ationError

Once the error has been converted to a laravel like error you can now
also return it as a go error.

The Prefix method is handy if you execute validation somewhere nested in
your codebase and want to prefix all validation error paths higher up in the
codebase.

error.go

@@ -22,6 +22,16 @@ func (v *ValidationError) Error() string {
 	return fallbackErrorMessage
 }
 
+func (v *LaravelValidationError) Error() string {
+	for _, entry := range v.Errors {
+		for _, message := range entry.Value {
+			return message
+		}
+	}
+
+	return fallbackErrorMessage
+}
+
 type FieldErrors struct {
 	Path   string                `json:"path"`
 	Errors []FieldValidatorError `json:"errors"`
@@ -67,6 +77,7 @@ func (obj LaravelErrorObj) MarshalJSON() ([]byte, error) {
 	return resp, nil
 }
 
+// ToLaravelError converts a ValidationError to Laravel like validation error
 func (e *ValidationError) ToLaravelError() *LaravelValidationError {
 	errors := LaravelErrorObj{}
 
@@ -88,3 +99,11 @@ func (e *ValidationError) ToLaravelError() *LaravelValidationError {
 		Message: "Form contains errors",
 	}
 }
+
+// Prefix prefixes all paths in the error with the given prefix
+func (e *ValidationError) Prefix(prefix string) {
+	for idx, fieldError := range e.Errors {
+		fieldError.Path = prefix + fieldError.Path
+		e.Errors[idx] = fieldError
+	}
+}