fixup batch publish

create correct go slice

Signed-off-by: Василий Толстов <v.tolstov@unistack.org>

go.mod

@@ -8,6 +8,6 @@ require (
 	github.com/nats-io/nats.go v1.13.1-0.20220308171302-2f2f6968e98d
 	go.unistack.org/micro/v3 v3.10.14
 	golang.org/x/crypto v0.0.0-20220307211146-efcb8507fb70 // indirect
-	golang.org/x/sync v0.1.0
+	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
 	google.golang.org/protobuf v1.28.1 // indirect
 )

go.sum

@@ -36,8 +36,8 @@ golang.org/x/crypto v0.0.0-20220307211146-efcb8507fb70 h1:syTAU9FwmvzEoIYMqcPHOc
 golang.org/x/crypto v0.0.0-20220307211146-efcb8507fb70/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
-golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
-golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c h1:5KslGYwFpkhGh+Q16bwMP3cOontH8FOep7tGV86Y7SQ=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190130150945-aca44879d564/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

nats.go

@@ -204,7 +204,7 @@ func (n *natsBroker) Options() broker.Options {
 
 func (n *natsBroker) BatchPublish(ctx context.Context, p []*broker.Message, opts ...broker.PublishOption) error {
 	var err error
-	msgs := make([]*nats.Msg, len(p))
+	msgs := make([]*nats.Msg, 0, len(p))
 	var wg sync.WaitGroup
 
 	wg.Add(len(p))