cmd: prefer nil slices over zero-length slices (#19077)

cmd/swarm/access.go

@@ -178,8 +178,8 @@ func accessNewACT(ctx *cli.Context) {
 		accessKey            []byte
 		err                  error
 		ref                  = args[0]
-		pkGrantees           = []string{}
-		passGrantees         = []string{}
+		pkGrantees           []string
+		passGrantees         []string
 		pkGranteesFilename   = ctx.String(SwarmAccessGrantKeysFlag.Name)
 		passGranteesFilename = ctx.String(utils.PasswordFileFlag.Name)
 		privateKey           = getPrivKey(ctx)

cmd/swarm/access_test.go

@@ -397,7 +397,7 @@ func testACT(t *testing.T, bogusEntries int) {
 	}
 
 	ref := matches[0]
-	grantees := []string{}
+	var grantees []string
 	for i, v := range cluster.Nodes {
 		if i == nodeToSkip {
 			continue
@@ -408,7 +408,7 @@ func testACT(t *testing.T, bogusEntries int) {
 	}
 
 	if bogusEntries > 0 {
-		bogusGrantees := []string{}
+		var bogusGrantees []string
 
 		for i := 0; i < bogusEntries; i++ {
 			prv, err := ecies.GenerateKey(rand.Reader, DefaultCurve, nil)

cmd/swarm/fs.go

@@ -123,7 +123,7 @@ func listMounts(cliContext *cli.Context) {
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()
 
-	mf := []fuse.MountInfo{}
+	var mf []fuse.MountInfo
 	err = client.CallContext(ctx, &mf, "swarmfs_listmounts")
 	if err != nil {
 		utils.Fatalf("encountered an error calling the RPC endpoint while listing mounts: %v", err)

cmd/swarm/swarm-smoke/sliding_window.go

@@ -56,7 +56,7 @@ func slidingWindowCmd(ctx *cli.Context, tuid string) error {
 }
 
 func slidingWindow(ctx *cli.Context, tuid string) error {
-	hashes := []uploadResult{} //swarm hashes of the uploads
+	var hashes []uploadResult //swarm hashes of the uploads
 	nodes := len(hosts)
 	const iterationTimeout = 30 * time.Second
 	log.Info("sliding window test started", "tuid", tuid, "nodes", nodes, "filesize(kb)", filesize, "timeout", timeout)