Move `disableFlagsInUseLine` from `main` into our `cli` library

... and expose. I would like to use this from another site.

This implies also moving (and exposing) the `visitAll` helper.

Unit test them while I'm here.

Signed-off-by: Ian Campbell <ijc@docker.com>

cli/cobra.go

@@ -46,6 +46,25 @@ func FlagErrorFunc(cmd *cobra.Command, err error) error {
 	}
 }
 
+// VisitAll will traverse all commands from the root.
+// This is different from the VisitAll of cobra.Command where only parents
+// are checked.
+func VisitAll(root *cobra.Command, fn func(*cobra.Command)) {
+	for _, cmd := range root.Commands() {
+		VisitAll(cmd, fn)
+	}
+	fn(root)
+}
+
+// DisableFlagsInUseLine sets the DisableFlagsInUseLine flag on all
+// commands within the tree rooted at cmd.
+func DisableFlagsInUseLine(cmd *cobra.Command) {
+	VisitAll(cmd, func(ccmd *cobra.Command) {
+		// do not add a `[flags]` to the end of the usage line.
+		ccmd.DisableFlagsInUseLine = true
+	})
+}
+
 var helpCommand = &cobra.Command{
 	Use:               "help [command]",
 	Short:             "Help about the command",

cli/cobra_test.go

@@ -0,0 +1,30 @@
+package cli
+
+import (
+	"testing"
+
+	"github.com/spf13/cobra"
+	"gotest.tools/assert"
+)
+
+func TestVisitAll(t *testing.T) {
+	root := &cobra.Command{Use: "root"}
+	sub1 := &cobra.Command{Use: "sub1"}
+	sub1sub1 := &cobra.Command{Use: "sub1sub1"}
+	sub1sub2 := &cobra.Command{Use: "sub1sub2"}
+	sub2 := &cobra.Command{Use: "sub2"}
+
+	root.AddCommand(sub1, sub2)
+	sub1.AddCommand(sub1sub1, sub1sub2)
+
+	// Take the opportunity to test DisableFlagsInUseLine too
+	DisableFlagsInUseLine(root)
+
+	var visited []string
+	VisitAll(root, func(ccmd *cobra.Command) {
+		visited = append(visited, ccmd.Name())
+		assert.Assert(t, ccmd.DisableFlagsInUseLine, "DisableFlagsInUseLine not set on %q", ccmd.Name())
+	})
+	expected := []string{"sub1sub1", "sub1sub2", "sub1", "sub2", "root"}
+	assert.DeepEqual(t, expected, visited)
+}

cmd/docker/docker.go

@@ -57,19 +57,12 @@ func newDockerCommand(dockerCli *command.DockerCli) *cobra.Command {
 	cmd.SetOutput(dockerCli.Out())
 	commands.AddCommands(cmd, dockerCli)
 
-	disableFlagsInUseLine(cmd)
+	cli.DisableFlagsInUseLine(cmd)
 	setValidateArgs(dockerCli, cmd, flags, opts)
 
 	return cmd
 }
 
-func disableFlagsInUseLine(cmd *cobra.Command) {
-	visitAll(cmd, func(ccmd *cobra.Command) {
-		// do not add a `[flags]` to the end of the usage line.
-		ccmd.DisableFlagsInUseLine = true
-	})
-}
-
 func setFlagErrorFunc(dockerCli *command.DockerCli, cmd *cobra.Command, flags *pflag.FlagSet, opts *cliflags.ClientOptions) {
 	// When invoking `docker stack --nonsense`, we need to make sure FlagErrorFunc return appropriate
 	// output if the feature is not supported.
@@ -111,7 +104,7 @@ func setValidateArgs(dockerCli *command.DockerCli, cmd *cobra.Command, flags *pf
 	// As a result, here we replace the existing Args validation func to a wrapper,
 	// where the wrapper will check to see if the feature is supported or not.
 	// The Args validation error will only be returned if the feature is supported.
-	visitAll(cmd, func(ccmd *cobra.Command) {
+	cli.VisitAll(cmd, func(ccmd *cobra.Command) {
 		// if there is no tags for a command or any of its parent,
 		// there is no need to wrap the Args validation.
 		if !hasTags(ccmd) {
@@ -145,16 +138,6 @@ func initializeDockerCli(dockerCli *command.DockerCli, flags *pflag.FlagSet, opt
 	return dockerCli.Initialize(opts)
 }
 
-// visitAll will traverse all commands from the root.
-// This is different from the VisitAll of cobra.Command where only parents
-// are checked.
-func visitAll(root *cobra.Command, fn func(*cobra.Command)) {
-	for _, cmd := range root.Commands() {
-		visitAll(cmd, fn)
-	}
-	fn(root)
-}
-
 func noArgs(cmd *cobra.Command, args []string) error {
 	if len(args) == 0 {
 		return nil