feat(completion): add default completion hidden if there are no subcmds

completions.go

@@ -586,7 +586,7 @@ func checkIfFlagCompletion(finalCmd *Command, args []string, lastArg string) (*p
 // 2- c has no subcommands (to avoid creating one),
 // 3- c already has a 'completion' command provided by the program.
 func (c *Command) initDefaultCompletionCmd() {
-	if c.CompletionOptions.DisableDefaultCmd || !c.HasSubCommands() {
+	if c.CompletionOptions.DisableDefaultCmd {
 		return
 	}
 
@@ -598,6 +598,7 @@ func (c *Command) initDefaultCompletionCmd() {
 	}
 
 	haveNoDescFlag := !c.CompletionOptions.DisableNoDescFlag && !c.CompletionOptions.DisableDescriptions
+	hidden := c.CompletionOptions.HiddenDefaultCmd || !c.HasSubCommands()
 
 	completionCmd := &Command{
 		Use:   compCmdName,
@@ -607,7 +608,7 @@ See each sub-command's help for details on how to use the generated script.
 `, c.Root().Name()),
 		Args:              NoArgs,
 		ValidArgsFunction: NoFileCompletions,
-		Hidden:            c.CompletionOptions.HiddenDefaultCmd,
+		Hidden:            hidden,
 	}
 	c.AddCommand(completionCmd)
 

completions_test.go

@@ -2287,14 +2287,21 @@ func TestDefaultCompletionCmd(t *testing.T) {
 		Run:  emptyRun,
 	}
 
-	// Test that no completion command is created if there are not other sub-commands
+	// Test that default completion command is created, hidden if there are no other sub-commands
 	assertNoErr(t, rootCmd.Execute())
+	found := false
 	for _, cmd := range rootCmd.commands {
 		if cmd.Name() == compCmdName {
-			t.Errorf("Should not have a 'completion' command when there are no other sub-commands of root")
+			found = true
+			if !cmd.Hidden {
+				t.Errorf("The 'completion' command should be hidden when there are no other sub-commands of root")
+			}
 			break
 		}
 	}
+	if !found {
+		t.Errorf("Should have a 'completion' command when there are no other sub-commands of root")
+	}
 
 	subCmd := &Command{
 		Use: "sub",
@@ -2303,7 +2310,7 @@ func TestDefaultCompletionCmd(t *testing.T) {
 	rootCmd.AddCommand(subCmd)
 
 	// Test that a completion command is created if there are other sub-commands
-	found := false
+	found = false
 	assertNoErr(t, rootCmd.Execute())
 	for _, cmd := range rootCmd.commands {
 		if cmd.Name() == compCmdName {

shell_completions.md

@@ -8,7 +8,8 @@ The currently supported shells are:
 - PowerShell
 
 Cobra will automatically provide your program with a fully functional `completion` command,
-similarly to how it provides the `help` command.
+similarly to how it provides the `help` command. If there are no other subcommands, the
+default `completion` command will be hidden, but still functional.
 
 ## Creating your own completion command