Add experimental huh-only prompter gated by GH_EXPERIMENTAL_PROMPTER

Introduce a new Prompter implementation (huhPrompter) that uses the
charmbracelet/huh library in its standard interactive mode, as an
alternative to the survey-based default prompter. The new implementation
is gated behind the GH_EXPERIMENTAL_PROMPTER environment variable,
following the same truthy/falsey pattern as GH_ACCESSIBLE_PROMPTER.

Key differences from the accessible prompter:
- No WithAccessible(true) flag (full interactive TUI)
- Uses EchoModePassword (masked with *) instead of EchoModeNone
- No default value annotations appended to prompt text

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

internal/prompter/huh_prompter.go

@@ -0,0 +1,226 @@
+package prompter
+
+import (
+	"fmt"
+	"slices"
+
+	"github.com/charmbracelet/huh"
+	"github.com/cli/cli/v2/internal/ghinstance"
+	"github.com/cli/cli/v2/pkg/surveyext"
+	ghPrompter "github.com/cli/go-gh/v2/pkg/prompter"
+)
+
+type huhPrompter struct {
+	stdin     ghPrompter.FileReader
+	stdout    ghPrompter.FileWriter
+	stderr    ghPrompter.FileWriter
+	editorCmd string
+}
+
+func (p *huhPrompter) newForm(groups ...*huh.Group) *huh.Form {
+	return huh.NewForm(groups...).
+		WithTheme(huh.ThemeBase16()).
+		WithInput(p.stdin).
+		WithOutput(p.stdout)
+}
+
+func (p *huhPrompter) Select(prompt, defaultValue string, options []string) (int, error) {
+	var result int
+
+	if !slices.Contains(options, defaultValue) {
+		defaultValue = ""
+	}
+
+	formOptions := make([]huh.Option[int], len(options))
+	for i, o := range options {
+		if defaultValue == o {
+			result = i
+		}
+		formOptions[i] = huh.NewOption(o, i)
+	}
+
+	err := p.newForm(
+		huh.NewGroup(
+			huh.NewSelect[int]().
+				Title(prompt).
+				Value(&result).
+				Options(formOptions...),
+		),
+	).Run()
+
+	return result, err
+}
+
+func (p *huhPrompter) MultiSelect(prompt string, defaults []string, options []string) ([]int, error) {
+	var result []int
+
+	defaults = slices.DeleteFunc(defaults, func(s string) bool {
+		return !slices.Contains(options, s)
+	})
+
+	formOptions := make([]huh.Option[int], len(options))
+	for i, o := range options {
+		if slices.Contains(defaults, o) {
+			result = append(result, i)
+		}
+		formOptions[i] = huh.NewOption(o, i)
+	}
+
+	err := p.newForm(
+		huh.NewGroup(
+			huh.NewMultiSelect[int]().
+				Title(prompt).
+				Value(&result).
+				Limit(len(options)).
+				Options(formOptions...),
+		),
+	).Run()
+
+	if err != nil {
+		return nil, err
+	}
+	return result, nil
+}
+
+func (p *huhPrompter) MultiSelectWithSearch(prompt, searchPrompt string, defaultValues, persistentValues []string, searchFunc func(string) MultiSelectSearchResult) ([]string, error) {
+	return multiSelectWithSearch(p, prompt, searchPrompt, defaultValues, persistentValues, searchFunc)
+}
+
+func (p *huhPrompter) Input(prompt, defaultValue string) (string, error) {
+	result := defaultValue
+
+	err := p.newForm(
+		huh.NewGroup(
+			huh.NewInput().
+				Title(prompt).
+				Value(&result),
+		),
+	).Run()
+
+	return result, err
+}
+
+func (p *huhPrompter) Password(prompt string) (string, error) {
+	var result string
+
+	err := p.newForm(
+		huh.NewGroup(
+			huh.NewInput().
+				EchoMode(huh.EchoModePassword).
+				Title(prompt).
+				Value(&result),
+		),
+	).Run()
+
+	if err != nil {
+		return "", err
+	}
+	return result, nil
+}
+
+func (p *huhPrompter) Confirm(prompt string, defaultValue bool) (bool, error) {
+	result := defaultValue
+
+	err := p.newForm(
+		huh.NewGroup(
+			huh.NewConfirm().
+				Title(prompt).
+				Value(&result),
+		),
+	).Run()
+
+	if err != nil {
+		return false, err
+	}
+	return result, nil
+}
+
+func (p *huhPrompter) AuthToken() (string, error) {
+	var result string
+
+	err := p.newForm(
+		huh.NewGroup(
+			huh.NewInput().
+				EchoMode(huh.EchoModePassword).
+				Title("Paste your authentication token:").
+				Validate(func(input string) error {
+					if input == "" {
+						return fmt.Errorf("token is required")
+					}
+					return nil
+				}).
+				Value(&result),
+		),
+	).Run()
+
+	return result, err
+}
+
+func (p *huhPrompter) ConfirmDeletion(requiredValue string) error {
+	return p.newForm(
+		huh.NewGroup(
+			huh.NewInput().
+				Title(fmt.Sprintf("Type %q to confirm deletion", requiredValue)).
+				Validate(func(input string) error {
+					if input != requiredValue {
+						return fmt.Errorf("You entered: %q", input)
+					}
+					return nil
+				}),
+		),
+	).Run()
+}
+
+func (p *huhPrompter) InputHostname() (string, error) {
+	var result string
+
+	err := p.newForm(
+		huh.NewGroup(
+			huh.NewInput().
+				Title("Hostname:").
+				Validate(ghinstance.HostnameValidator).
+				Value(&result),
+		),
+	).Run()
+
+	if err != nil {
+		return "", err
+	}
+	return result, nil
+}
+
+func (p *huhPrompter) MarkdownEditor(prompt, defaultValue string, blankAllowed bool) (string, error) {
+	var result string
+	skipOption := "skip"
+	launchOption := "launch"
+	options := []huh.Option[string]{
+		huh.NewOption(fmt.Sprintf("Launch %s", surveyext.EditorName(p.editorCmd)), launchOption),
+	}
+	if blankAllowed {
+		options = append(options, huh.NewOption("Skip", skipOption))
+	}
+
+	err := p.newForm(
+		huh.NewGroup(
+			huh.NewSelect[string]().
+				Title(prompt).
+				Options(options...).
+				Value(&result),
+		),
+	).Run()
+
+	if err != nil {
+		return "", err
+	}
+
+	if result == skipOption {
+		return "", nil
+	}
+
+	text, err := surveyext.Edit(p.editorCmd, "*.md", defaultValue, p.stdin, p.stdout, p.stderr)
+	if err != nil {
+		return "", err
+	}
+
+	return text, nil
+}

internal/prompter/prompter.go

@@ -53,6 +53,15 @@ type Prompter interface {
 }
 
 func New(editorCmd string, io *iostreams.IOStreams) Prompter {
+	if io.ExperimentalPrompterEnabled() {
+		return &huhPrompter{
+			stdin:     io.In,
+			stdout:    io.Out,
+			stderr:    io.ErrOut,
+			editorCmd: editorCmd,
+		}
+	}
+
 	if io.AccessiblePrompterEnabled() {
 		return &accessiblePrompter{
 			stdin:     io.In,

pkg/cmd/factory/default.go

@@ -316,6 +316,13 @@ func ioStreams(f *cmdutil.Factory) *iostreams.IOStreams {
 		io.SetAccessiblePrompterEnabled(true)
 	}
 
+	experimentalPrompterValue, experimentalPrompterIsSet := os.LookupEnv("GH_EXPERIMENTAL_PROMPTER")
+	if experimentalPrompterIsSet {
+		if !slices.Contains(falseyValues, experimentalPrompterValue) {
+			io.SetExperimentalPrompterEnabled(true)
+		}
+	}
+
 	ghSpinnerDisabledValue, ghSpinnerDisabledIsSet := os.LookupEnv("GH_SPINNER_DISABLED")
 	if ghSpinnerDisabledIsSet {
 		if !slices.Contains(falseyValues, ghSpinnerDisabledValue) {

pkg/iostreams/iostreams.go

@@ -79,8 +79,9 @@ type IOStreams struct {
 	pagerCommand string
 	pagerProcess *os.Process
 
-	neverPrompt               bool
-	accessiblePrompterEnabled bool
+	neverPrompt                bool
+	accessiblePrompterEnabled  bool
+	experimentalPrompterEnabled bool
 
 	TempFileOverride *os.File
 }
@@ -466,6 +467,14 @@ func (s *IOStreams) AccessiblePrompterEnabled() bool {
 	return s.accessiblePrompterEnabled
 }
 
+func (s *IOStreams) SetExperimentalPrompterEnabled(enabled bool) {
+	s.experimentalPrompterEnabled = enabled
+}
+
+func (s *IOStreams) ExperimentalPrompterEnabled() bool {
+	return s.experimentalPrompterEnabled
+}
+
 func System() *IOStreams {
 	terminal := ghTerm.FromEnv()