feat(validate): add min/max errors for handling in app

validate/array.go

@@ -38,10 +38,10 @@ func (t Array) Set() bool {
 // ValidateLength returns error if array length v is invalid.
 func (t Array) ValidateLength(v int) error {
 	if t.MaxLengthSet && v > t.MaxLength {
-		return errors.Errorf("len %d greater than maximum %d", v, t.MaxLength)
+		return &MaxLengthError{Len: v, MaxLength: t.MaxLength}
 	}
 	if t.MinLengthSet && v < t.MinLength {
-		return errors.Errorf("len %d less than minimum %d", v, t.MinLength)
+		return &MinLengthError{Len: v, MinLength: t.MinLength}
 	}
 
 	return nil

validate/error.go

@@ -48,8 +48,8 @@ type InvalidContentTypeError struct {
 }
 
 // InvalidContentTypeError implements error.
-func (i *InvalidContentTypeError) Error() string {
-	return fmt.Sprintf("unexpected Content-Type: %s", i.ContentType)
+func (e *InvalidContentTypeError) Error() string {
+	return fmt.Sprintf("unexpected Content-Type: %s", e.ContentType)
 }
 
 // InvalidContentType creates new InvalidContentTypeError.
@@ -72,9 +72,31 @@ func UnexpectedStatusCode(statusCode int) error {
 }
 
 // UnexpectedStatusCodeError implements error.
-func (i *UnexpectedStatusCodeError) Error() string {
-	return fmt.Sprintf("unexpected status code: %d", i.StatusCode)
+func (e *UnexpectedStatusCodeError) Error() string {
+	return fmt.Sprintf("unexpected status code: %d", e.StatusCode)
 }
 
 // ErrNilPointer reports that use Validate, but receiver pointer is nil.
 var ErrNilPointer = errors.New("nil pointer")
+
+// MinLengthError reports that len less than minimum.
+type MinLengthError struct {
+	Len       int
+	MinLength int
+}
+
+// MinLengthError implements error.
+func (e *MinLengthError) Error() string {
+	return fmt.Sprintf("len %d less than minimum %d", e.Len, e.MinLength)
+}
+
+// MaxLengthError reports that len greater than maximum.
+type MaxLengthError struct {
+	Len       int
+	MaxLength int
+}
+
+// MaxLengthError implements error.
+func (e *MaxLengthError) Error() string {
+	return fmt.Sprintf("len %d greater than maximum %d", e.Len, e.MaxLength)
+}