Complete subcommands when TraverseChildren is set (#1171)

* Complete subcommands when TraverseChildren is true in custom completion

The current custom completion logic does not complete
subcommands when a local flag is set. This is good unless
TraverseChildren is set to true where local flags
can be set on parent commands.

This commit allows subcommands to be completed
if TraverseChildren is set to true on the root cmd.

Closes #1170

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

* Complete subcommands when TraverseChildren is true in bash completion

The current bash completion logic does not complete
subcommands when a local flag is set. There is also a bug
where subcommands are sometimes still getting completed. see: #1172

If TraverseChildren is true we should allow subcommands
to be completed even if a local flag is set.

Closes #1172

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

bash_completions.go

@@ -495,12 +495,14 @@ func writeFlag(buf *bytes.Buffer, flag *pflag.Flag, cmd *Command) {
 
 func writeLocalNonPersistentFlag(buf *bytes.Buffer, flag *pflag.Flag) {
 	name := flag.Name
-	format := "    local_nonpersistent_flags+=(\"--%s"
+	format := "    local_nonpersistent_flags+=(\"--%[1]s\")\n"
 	if len(flag.NoOptDefVal) == 0 {
-		format += "="
+		format += "    local_nonpersistent_flags+=(\"--%[1]s=\")\n"
 	}
-	format += "\")\n"
 	buf.WriteString(fmt.Sprintf(format, name))
+	if len(flag.Shorthand) > 0 {
+		buf.WriteString(fmt.Sprintf("    local_nonpersistent_flags+=(\"-%s\")\n", flag.Shorthand))
+	}
 }
 
 // Setup annotations for go completions for registered flags
@@ -535,7 +537,9 @@ func writeFlags(buf *bytes.Buffer, cmd *Command) {
 		if len(flag.Shorthand) > 0 {
 			writeShortFlag(buf, flag, cmd)
 		}
-		if localNonPersistentFlags.Lookup(flag.Name) != nil {
+		// localNonPersistentFlags are used to stop the completion of subcommands when one is set
+		// if TraverseChildren is true we should allow to complete subcommands
+		if localNonPersistentFlags.Lookup(flag.Name) != nil && !cmd.Root().TraverseChildren {
 			writeLocalNonPersistentFlag(buf, flag)
 		}
 	})

bash_completions_test.go

@@ -193,6 +193,13 @@ func TestBashCompletions(t *testing.T) {
 	checkOmit(t, output, `two_word_flags+=("--two-w-default")`)
 	checkOmit(t, output, `two_word_flags+=("-T")`)
 
+	// check local nonpersistent flag
+	check(t, output, `local_nonpersistent_flags+=("--two")`)
+	check(t, output, `local_nonpersistent_flags+=("--two=")`)
+	check(t, output, `local_nonpersistent_flags+=("-t")`)
+	check(t, output, `local_nonpersistent_flags+=("--two-w-default")`)
+	check(t, output, `local_nonpersistent_flags+=("-T")`)
+
 	checkOmit(t, output, deprecatedCmd.Name())
 
 	// If available, run shellcheck against the script.
@@ -235,3 +242,21 @@ func TestBashCompletionDeprecatedFlag(t *testing.T) {
 		t.Errorf("expected completion to not include %q flag: Got %v", flagName, output)
 	}
 }
+
+func TestBashCompletionTraverseChildren(t *testing.T) {
+	c := &Command{Use: "c", Run: emptyRun, TraverseChildren: true}
+
+	c.Flags().StringP("string-flag", "s", "", "string flag")
+	c.Flags().BoolP("bool-flag", "b", false, "bool flag")
+
+	buf := new(bytes.Buffer)
+	c.GenBashCompletion(buf)
+	output := buf.String()
+
+	// check that local nonpersistent flag are not set since we have TraverseChildren set to true
+	checkOmit(t, output, `local_nonpersistent_flags+=("--string-flag")`)
+	checkOmit(t, output, `local_nonpersistent_flags+=("--string-flag=")`)
+	checkOmit(t, output, `local_nonpersistent_flags+=("-s")`)
+	checkOmit(t, output, `local_nonpersistent_flags+=("--bool-flag")`)
+	checkOmit(t, output, `local_nonpersistent_flags+=("-b")`)
+}

custom_completions.go

@@ -175,8 +175,16 @@ func (c *Command) getCompletions(args []string) (*Command, []string, ShellCompDi
 	toComplete := args[len(args)-1]
 	trimmedArgs := args[:len(args)-1]
 
+	var finalCmd *Command
+	var finalArgs []string
+	var err error
 	// Find the real command for which completion must be performed
-	finalCmd, finalArgs, err := c.Root().Find(trimmedArgs)
+	// check if we need to traverse here to parse local flags on parent commands
+	if c.Root().TraverseChildren {
+		finalCmd, finalArgs, err = c.Root().Traverse(trimmedArgs)
+	} else {
+		finalCmd, finalArgs, err = c.Root().Find(trimmedArgs)
+	}
 	if err != nil {
 		// Unable to find the real command. E.g., <program> someInvalidCmd <TAB>
 		return c, []string{}, ShellCompDirectiveDefault, fmt.Errorf("Unable to find a command for arguments: %v", trimmedArgs)
@@ -271,20 +279,24 @@ func (c *Command) getCompletions(args []string) (*Command, []string, ShellCompDi
 	var completions []string
 	directive := ShellCompDirectiveDefault
 	if flag == nil {
-		// Check if there are any local, non-persistent flags on the command-line
 		foundLocalNonPersistentFlag := false
+		// If TraverseChildren is true on the root command we don't check for
+		// local flags because we can use a local flag on a parent command
+		if !finalCmd.Root().TraverseChildren {
+			// Check if there are any local, non-persistent flags on the command-line
 			localNonPersistentFlags := finalCmd.LocalNonPersistentFlags()
 			finalCmd.NonInheritedFlags().VisitAll(func(flag *pflag.Flag) {
 				if localNonPersistentFlags.Lookup(flag.Name) != nil && flag.Changed {
 					foundLocalNonPersistentFlag = true
 				}
 			})
+		}
 
 		// Complete subcommand names, including the help command
 		if len(finalArgs) == 0 && !foundLocalNonPersistentFlag {
 			// We only complete sub-commands if:
 			// - there are no arguments on the command-line and
-			// - there are no local, non-peristent flag on the command-line
+			// - there are no local, non-peristent flag on the command-line or TraverseChildren is true
 			for _, subCmd := range finalCmd.Commands() {
 				if subCmd.IsAvailableCommand() || subCmd == finalCmd.helpCommand {
 					if strings.HasPrefix(subCmd.Name(), toComplete) {

custom_completions_test.go

@@ -139,6 +139,8 @@ func TestNoCmdNameCompletionInGo(t *testing.T) {
 		Use: "root",
 		Run: emptyRun,
 	}
+	rootCmd.Flags().String("localroot", "", "local root flag")
+
 	childCmd1 := &Command{
 		Use:   "childCmd1",
 		Short: "First command",
@@ -187,6 +189,64 @@ func TestNoCmdNameCompletionInGo(t *testing.T) {
 		t.Errorf("expected: %q, got: %q", expected, output)
 	}
 
+	// Test that sub-command names are completed if a local non-persistent flag is present and TraverseChildren is set to true
+	// set TraverseChildren to true on the root cmd
+	rootCmd.TraverseChildren = true
+
+	output, err = executeCommand(rootCmd, ShellCompNoDescRequestCmd, "--localroot", "value", "")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	// Reset TraverseChildren for next command
+	rootCmd.TraverseChildren = false
+
+	expected = strings.Join([]string{
+		"childCmd1",
+		"help",
+		":4",
+		"Completion ended with directive: ShellCompDirectiveNoFileComp", ""}, "\n")
+
+	if output != expected {
+		t.Errorf("expected: %q, got: %q", expected, output)
+	}
+
+	// Test that sub-command names from a child cmd are completed if a local non-persistent flag is present
+	// and TraverseChildren is set to true on the root cmd
+	rootCmd.TraverseChildren = true
+
+	output, err = executeCommand(rootCmd, ShellCompNoDescRequestCmd, "--localroot", "value", "childCmd1", "--nonPersistent", "value", "")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	// Reset TraverseChildren for next command
+	rootCmd.TraverseChildren = false
+	// Reset the flag for the next command
+	nonPersistentFlag.Changed = false
+
+	expected = strings.Join([]string{
+		"childCmd2",
+		":4",
+		"Completion ended with directive: ShellCompDirectiveNoFileComp", ""}, "\n")
+
+	if output != expected {
+		t.Errorf("expected: %q, got: %q", expected, output)
+	}
+
+	// Test that we don't use Traverse when we shouldn't.
+	// This command should not return a completion since the command line is invalid without TraverseChildren.
+	output, err = executeCommand(rootCmd, ShellCompNoDescRequestCmd, "--localroot", "value", "childCmd1", "")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	expected = strings.Join([]string{
+		":0",
+		"Completion ended with directive: ShellCompDirectiveDefault", ""}, "\n")
+
+	if output != expected {
+		t.Errorf("expected: %q, got: %q", expected, output)
+	}
+
 	// Test that sub-command names are not completed if a local non-persistent short flag is present
 	output, err = executeCommand(rootCmd, ShellCompNoDescRequestCmd, "childCmd1", "-n", "value", "")
 	if err != nil {