Fix:(issue_1814) Fix completions for subcommands

command.go

@@ -139,6 +139,8 @@ type Command struct {
 	isInError bool
 	// track state of defaults
 	didSetupDefaults bool
+	// whether in shell completion mode
+	shellCompletion bool
 }
 
 // FullName returns the full name of the command.
@@ -244,7 +246,7 @@ func (cmd *Command) setupDefaults(osArgs []string) {
 		cmd.SuggestCommandFunc = suggestCommand
 	}
 
-	if cmd.EnableShellCompletion {
+	if cmd.EnableShellCompletion || cmd.Root().shellCompletion {
 		completionCommand := buildCompletionCommand()
 
 		if cmd.ShellCompletionCommandName != "" {
@@ -346,16 +348,19 @@ func (cmd *Command) Run(ctx context.Context, osArgs []string) (deferErr error) {
 		cmd.parent = v
 	}
 
-	// handle the completion flag separately from the flagset since
-	// completion could be attempted after a flag, but before its value was put
-	// on the command line. this causes the flagset to interpret the completion
-	// flag name as the value of the flag before it which is undesirable
-	// note that we can only do this because the shell autocomplete function
-	// always appends the completion flag at the end of the command
-	enableShellCompletion, osArgs := checkShellCompleteFlag(cmd, osArgs)
+	if cmd.parent == nil {
+		// handle the completion flag separately from the flagset since
+		// completion could be attempted after a flag, but before its value was put
+		// on the command line. this causes the flagset to interpret the completion
+		// flag name as the value of the flag before it which is undesirable
+		// note that we can only do this because the shell autocomplete function
+		// always appends the completion flag at the end of the command
+		tracef("checking osArgs %v (cmd=%[2]q)", osArgs, cmd.Name)
+		cmd.shellCompletion, osArgs = checkShellCompleteFlag(cmd, osArgs)
 
-	tracef("setting cmd.EnableShellCompletion=%[1]v from checkShellCompleteFlag (cmd=%[2]q)", enableShellCompletion, cmd.Name)
-	cmd.EnableShellCompletion = enableShellCompletion
+		tracef("setting cmd.shellCompletion=%[1]v from checkShellCompleteFlag (cmd=%[2]q)", cmd.shellCompletion && cmd.EnableShellCompletion, cmd.Name)
+		cmd.shellCompletion = cmd.EnableShellCompletion && cmd.shellCompletion
+	}
 
 	tracef("using post-checkShellCompleteFlag arguments %[1]q (cmd=%[2]q)", osArgs, cmd.Name)
 
@@ -418,7 +423,7 @@ func (cmd *Command) Run(ctx context.Context, osArgs []string) (deferErr error) {
 		return nil
 	}
 
-	if cmd.After != nil && !cmd.EnableShellCompletion {
+	if cmd.After != nil && !cmd.Root().shellCompletion {
 		defer func() {
 			if err := cmd.After(ctx, cmd); err != nil {
 				err = cmd.handleExitCoder(ctx, err)
@@ -445,7 +450,7 @@ func (cmd *Command) Run(ctx context.Context, osArgs []string) (deferErr error) {
 		}
 	}
 
-	if cmd.Before != nil && !cmd.EnableShellCompletion {
+	if cmd.Before != nil && !cmd.Root().shellCompletion {
 		if err := cmd.Before(ctx, cmd); err != nil {
 			deferErr = cmd.handleExitCoder(ctx, err)
 			return deferErr
@@ -666,7 +671,7 @@ func (cmd *Command) parseFlags(args Args) (Args, error) {
 
 	tracef("parsing flags iteratively tail=%[1]q (cmd=%[2]q)", args.Tail(), cmd.Name)
 
-	if err := parseIter(cmd.flagSet, cmd, args.Tail(), cmd.Root().EnableShellCompletion); err != nil {
+	if err := parseIter(cmd.flagSet, cmd, args.Tail(), cmd.Root().shellCompletion); err != nil {
 		return cmd.Args(), err
 	}
 

completion_test.go

@@ -61,6 +61,33 @@ func TestCompletionShell(t *testing.T) {
 	}
 }
 
+func TestCompletionSubcommand(t *testing.T) {
+	out := &bytes.Buffer{}
+
+	cmd := &Command{
+		EnableShellCompletion: true,
+		Writer:                out,
+		Commands: []*Command{
+			{
+				Name: "bar",
+				Commands: []*Command{
+					{
+						Name: "xyz",
+					},
+				},
+			},
+		},
+	}
+
+	r := require.New(t)
+
+	r.NoError(cmd.Run(buildTestContext(t), []string{"foo", "bar", "--generate-shell-completion"}))
+	r.Containsf(
+		out.String(), "xyz",
+		"Expected output to contain shell name %[1]q", "xyz",
+	)
+}
+
 func TestCompletionInvalidShell(t *testing.T) {
 	cmd := &Command{
 		EnableShellCompletion: true,

help.go

@@ -218,8 +218,16 @@ func printFlagSuggestions(lastArg string, flags []Flag, writer io.Writer) {
 
 func DefaultCompleteWithFlags(cmd *Command) func(ctx context.Context, cmd *Command) {
 	return func(_ context.Context, cmd *Command) {
-		if len(os.Args) > 2 {
-			lastArg := os.Args[len(os.Args)-2]
+		args := os.Args
+		if cmd != nil && cmd.flagSet != nil && cmd.parent != nil {
+			args = cmd.Args().Slice()
+			tracef("running default complete with flags[%v] on command %[1]q", args, cmd.Name)
+		} else {
+			tracef("running default complete with os.Args flags")
+		}
+		argsLen := len(args)
+		if argsLen > 2 {
+			lastArg := args[argsLen-2]
 
 			if strings.HasPrefix(lastArg, "-") {
 				if cmd != nil {
@@ -235,11 +243,10 @@ func DefaultCompleteWithFlags(cmd *Command) func(ctx context.Context, cmd *Comma
 		}
 
 		if cmd != nil {
+			tracef("printing command suggestions on command %[1]q", cmd.Name)
 			printCommandSuggestions(cmd.Commands, cmd.Root().Writer)
 			return
 		}
-
-		printCommandSuggestions(cmd.Commands, cmd.Root().Writer)
 	}
 }
 
@@ -431,7 +438,7 @@ func checkVersion(cmd *Command) bool {
 }
 
 func checkShellCompleteFlag(c *Command, arguments []string) (bool, []string) {
-	if !c.EnableShellCompletion {
+	if (c.parent == nil && !c.EnableShellCompletion) || (c.parent != nil && !c.Root().shellCompletion) {
 		return false, arguments
 	}
 
@@ -448,7 +455,7 @@ func checkShellCompleteFlag(c *Command, arguments []string) (bool, []string) {
 func checkCompletions(ctx context.Context, cmd *Command) bool {
 	tracef("checking completions on command %[1]q", cmd.Name)
 
-	if !cmd.EnableShellCompletion {
+	if !cmd.Root().shellCompletion {
 		return false
 	}
 
@@ -461,6 +468,7 @@ func checkCompletions(ctx context.Context, cmd *Command) bool {
 	}
 
 	if cmd.ShellComplete != nil {
+		tracef("running shell completion func for command %[1]q", cmd.Name)
 		cmd.ShellComplete(ctx, cmd)
 	}