PCSM-236: Better error message for unsupported operations (#166)

Author: inelpandzic

errors/errors.go

@@ -5,9 +5,6 @@ import (
 	"fmt"
 )
 
-// ErrUnsupported indicates an unsupported operation.
-var ErrUnsupported = errors.ErrUnsupported
-
 // wrappedError wraps an error with an additional message.
 type wrappedError struct {
 	cause error

pcsm/events.go

@@ -612,9 +612,9 @@ func parseChangeEvent(data bson.Raw, change *ChangeEvent) error {
 		change.Event = e
 
 	case ReshardCollection:
-		return errors.ErrUnsupported
+		return errors.New("reshardCollection operation is not supported")
 	case RefineCollectionShardKey:
-		return errors.ErrUnsupported
+		return errors.New("refineCollectionShardKey operation is not supported")
 
 	case Invalidate:
 		return ErrInvalidateEvent