refactor: clean code

internal/domain/error.go

@@ -0,0 +1,30 @@
+package domain
+
+var (
+	ErrInvalidParams  = NewError(400, "invalid params")
+	ErrRecordNotFound = NewError(404, "record not found")
+)
+
+type Error struct {
+	Code int    `json:"code"`
+	Msg  string `json:"msg"`
+}
+
+func NewError(code int, msg string) *Error {
+	if code == 0 {
+		code = -1
+	}
+
+	return &Error{code, msg}
+}
+
+func (e *Error) Error() string {
+	return e.Msg
+}
+
+func IsRecordNotFoundError(err error) bool {
+	if e, ok := err.(*Error); ok {
+		return e.Code == ErrRecordNotFound.Code
+	}
+	return false
+}