fix broken cmdable interface of redis.Tx

commands.go

@@ -40,10 +40,7 @@ func formatSec(dur time.Duration) string {
 	return strconv.FormatInt(int64(dur/time.Second), 10)
 }
 
-type Cmdable interface {
-	Pipeline() *Pipeline
-	Pipelined(fn func(*Pipeline) error) ([]Cmder, error)
-
+type BaseCmdable interface {
 	Echo(message interface{}) *StringCmd
 	Ping() *StatusCmd
 	Quit() *StatusCmd
@@ -238,6 +235,12 @@ type Cmdable interface {
 	Command() *CommandsInfoCmd
 }
 
+type Cmdable interface {
+	Pipeline() *Pipeline
+	Pipelined(fn func(*Pipeline) error) ([]Cmder, error)
+	BaseCmdable
+}
+
 type cmdable struct {
 	process func(cmd Cmder) error
 }

tx.go

@@ -28,6 +28,8 @@ type Tx struct {
 	closed bool
 }
 
+var _ BaseCmdable = (*Tx)(nil)
+
 func (c *Client) newTx() *Tx {
 	tx := Tx{
 		baseClient: baseClient{