Maintenance: improve error wrapping

internal/server/wrappers.go

@@ -1,6 +1,7 @@
 package server
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/qdm12/gluetun/internal/constants"
@@ -11,15 +12,16 @@ type statusWrapper struct {
 	Status string `json:"status"`
 }
 
+var errInvalidStatus = errors.New("invalid status")
+
 func (sw *statusWrapper) getStatus() (status models.LoopStatus, err error) {
 	status = models.LoopStatus(sw.Status)
 	switch status {
 	case constants.Stopped, constants.Running:
 		return status, nil
 	default:
-		return "", fmt.Errorf(
-			"invalid status %q: possible values are: %s, %s",
-			sw.Status, constants.Stopped, constants.Running)
+		return "", fmt.Errorf("%w: %s: possible values are: %s, %s",
+			errInvalidStatus, sw.Status, constants.Stopped, constants.Running)
 	}
 }