refactor: replace creack/pty with aymanbagabas/go-pty for cross-platform PTY support (Refs: beans-bz15)

.beans/beans-bz15--migrate-from-creackpty-to-aymanbagabasgo-pty-for-c.md

@@ -0,0 +1,19 @@
+---
+# beans-bz15
+title: Migrate from creack/pty to aymanbagabas/go-pty for cross-platform PTY support
+status: completed
+type: task
+priority: normal
+created_at: 2026-03-20T17:50:59Z
+updated_at: 2026-03-20T17:53:49Z
+---
+
+Replace creack/pty (Unix-only, unmaintained) with aymanbagabas/go-pty which provides a unified API for Unix PTY and Windows ConPTY. Only internal/terminal/terminal.go needs changes.
+
+## Summary of Changes
+
+Replaced `creack/pty` with `aymanbagabas/go-pty` in `internal/terminal/terminal.go`:
+- Swapped `*os.File` PTY handle for `gopty.Pty` interface (`io.ReadWriteCloser` + `Resize`)
+- Swapped `*exec.Cmd` for `*gopty.Cmd` (same API: `Process`, `Start`, `Wait`)
+- Added `defaultShell()` helper with Windows support (`pwsh.exe`/`cmd.exe` fallback)
+- All existing tests pass, no API changes to `Session` or `Manager`

go.mod

@@ -8,12 +8,12 @@ require (
 	github.com/99designs/gqlgen v0.17.84
 	github.com/adrg/frontmatter v0.2.0
 	github.com/atotto/clipboard v0.1.4
+	github.com/aymanbagabas/go-pty v0.2.2
 	github.com/blevesearch/bleve/v2 v2.5.6
 	github.com/charmbracelet/bubbles v0.21.1-0.20250623103423-23b8fd6302d7
 	github.com/charmbracelet/bubbletea v1.3.10
 	github.com/charmbracelet/glamour v0.10.0
 	github.com/charmbracelet/lipgloss v1.1.1-0.20250404203927-76690c660834
-	github.com/creack/pty v1.1.24
 	github.com/fsnotify/fsnotify v1.9.0
 	github.com/gin-gonic/gin v1.11.0
 	github.com/google/uuid v1.6.0
@@ -62,6 +62,7 @@ require (
 	github.com/clipperhouse/stringish v0.1.1 // indirect
 	github.com/clipperhouse/uax29/v2 v2.3.0 // indirect
 	github.com/cloudwego/base64x v0.1.6 // indirect
+	github.com/creack/pty v1.1.24 // indirect
 	github.com/dlclark/regexp2 v1.11.5 // indirect
 	github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f // indirect
 	github.com/gabriel-vasile/mimetype v1.4.8 // indirect
@@ -99,6 +100,7 @@ require (
 	github.com/sosodev/duration v1.3.1 // indirect
 	github.com/spf13/pflag v1.0.10 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
+	github.com/u-root/u-root v0.11.0 // indirect
 	github.com/ugorji/go/codec v1.3.0 // indirect
 	github.com/urfave/cli/v3 v3.6.1 // indirect
 	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect

go.sum

@@ -27,6 +27,8 @@ github.com/atotto/clipboard v0.1.4 h1:EH0zSVneZPSuFR11BlR9YppQTVDbh5+16AmcJi4g1z
 github.com/atotto/clipboard v0.1.4/go.mod h1:ZY9tmq7sm5xIbd9bOK4onWV4S6X0u6GY7Vn0Yu86PYI=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1 h1:HwpRHbFMcZLEVr42D4p7XBqjyuxQH5SMiErDT4WkJ2k=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1/go.mod h1:uYgXzlJ7ZpABp8OJ+exZzJJhRNQ2ASbcXHWsFqH8hp8=
+github.com/aymanbagabas/go-pty v0.2.2 h1:YZREB4eSj+1xdbbItIokX0ekjjeifgJOA+ZvxU4/WM8=
+github.com/aymanbagabas/go-pty v0.2.2/go.mod h1:gfvlwH+0U66BCwxJREjJaAOEs9H1OFf3YFjI9WSiZ04=
 github.com/aymanbagabas/go-udiff v0.3.1 h1:LV+qyBQ2pqe0u42ZsUEtPiCaUoqgA9gYRDs3vj1nolY=
 github.com/aymanbagabas/go-udiff v0.3.1/go.mod h1:G0fsKmG+P6ylD0r6N/KgQD/nWzgfnl8ZBcNLgcbrw8E=
 github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuPk=
@@ -225,6 +227,10 @@ github.com/tidwall/pretty v1.2.1 h1:qjsOFOWWQl+N3RsoF5/ssm1pHmJJwhjlSbZ51I6wMl4=
 github.com/tidwall/pretty v1.2.1/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
 github.com/twitchyliquid64/golang-asm v0.15.1 h1:SU5vSMR7hnwNxj24w34ZyCi/FmDZTkS4MhqMhdFk5YI=
 github.com/twitchyliquid64/golang-asm v0.15.1/go.mod h1:a1lVb/DtPvCB8fslRZhAngC2+aY1QWCk3Cedj/Gdt08=
+github.com/u-root/gobusybox/src v0.0.0-20221229083637-46b2883a7f90 h1:zTk5683I9K62wtZ6eUa6vu6IWwVHXPnoKK5n2unAwv0=
+github.com/u-root/gobusybox/src v0.0.0-20221229083637-46b2883a7f90/go.mod h1:lYt+LVfZBBwDZ3+PHk4k/c/TnKOkjJXiJO73E32Mmpc=
+github.com/u-root/u-root v0.11.0 h1:6gCZLOeRyevw7gbTwMj3fKxnr9+yHFlgF3N7udUVNO8=
+github.com/u-root/u-root v0.11.0/go.mod h1:DBkDtiZyONk9hzVEdB/PWI9B4TxDkElWlVTHseglrZY=
 github.com/ugorji/go/codec v1.3.0 h1:Qd2W2sQawAfG8XSvzwhBeoGq71zXOC/Q1E9y/wUcsUA=
 github.com/ugorji/go/codec v1.3.0/go.mod h1:pRBVtBSKl77K30Bv8R2P+cLSGaTtex6fsA2Wjqmfxj4=
 github.com/urfave/cli/v3 v3.6.1 h1:j8Qq8NyUawj/7rTYdBGrxcH7A/j7/G8Q5LhWEW4G3Mo=

internal/terminal/terminal.go

@@ -4,9 +4,10 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+	"runtime"
 	"sync"
 
-	"github.com/creack/pty"
+	gopty "github.com/aymanbagabas/go-pty"
 )
 
 const scrollbackSize = 64 * 1024 // 64KB
@@ -67,10 +68,10 @@ func (r *RingBuffer) Bytes() []byte {
 
 // Session represents an active PTY session with scrollback buffering.
 type Session struct {
-	id   string
-	cmd  *exec.Cmd
-	ptyF *os.File // PTY master file descriptor
-	mu   sync.Mutex
+	id  string
+	pty gopty.Pty
+	cmd *gopty.Cmd
+	mu  sync.Mutex
 
 	scrollback *RingBuffer
 	scrollMu   sync.Mutex
@@ -85,14 +86,14 @@ type Session struct {
 
 // Write sends input to the PTY.
 func (s *Session) Write(data []byte) (int, error) {
-	return s.ptyF.Write(data)
+	return s.pty.Write(data)
 }
 
 // Resize changes the PTY window size.
 func (s *Session) Resize(cols, rows uint16) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	return pty.Setsize(s.ptyF, &pty.Winsize{Cols: cols, Rows: rows})
+	return s.pty.Resize(int(cols), int(rows))
 }
 
 // Attach connects a client to receive PTY output.
@@ -149,7 +150,7 @@ func (s *Session) readLoop() {
 	defer close(s.done)
 	buf := make([]byte, 4096)
 	for {
-		n, err := s.ptyF.Read(buf)
+		n, err := s.pty.Read(buf)
 		if n > 0 {
 			data := make([]byte, n)
 			copy(data, buf[:n])
@@ -183,10 +184,33 @@ func (s *Session) Close() {
 	if s.cmd.Process != nil {
 		_ = s.cmd.Process.Kill()
 	}
-	_ = s.ptyF.Close()
+	_ = s.pty.Close()
 	_ = s.cmd.Wait()
 }
 
+// closeSlave closes the slave end of a Unix PTY in the parent process after
+// the child has been started. This is necessary on Linux so the master gets
+// EOF when the child exits. On non-Unix platforms this is a no-op.
+func closeSlave(p gopty.Pty) {
+	if up, ok := p.(gopty.UnixPty); ok {
+		up.Slave().Close()
+	}
+}
+
+// defaultShell returns the default shell for the current platform.
+func defaultShell() string {
+	if runtime.GOOS == "windows" {
+		if ps, err := exec.LookPath("pwsh.exe"); err == nil {
+			return ps
+		}
+		return "cmd.exe"
+	}
+	if shell := os.Getenv("SHELL"); shell != "" {
+		return shell
+	}
+	return "/bin/sh"
+}
+
 // EnvFunc returns extra environment variables for a given session ID.
 // Used to inject workspace-specific env vars (e.g. BEANS_WORKSPACE_PORT).
 type EnvFunc func(sessionID string) []string
@@ -241,28 +265,38 @@ func (m *Manager) GetOrCreate(sessionID, workDir string, cols, rows uint16) (*Se
 }
 
 func (m *Manager) createLocked(sessionID, workDir string, cols, rows uint16) (*Session, error) {
-	shell := os.Getenv("SHELL")
-	if shell == "" {
-		shell = "/bin/sh"
+	shell := defaultShell()
+
+	p, err := gopty.New()
+	if err != nil {
+		return nil, fmt.Errorf("failed to create PTY: %w", err)
+	}
+
+	if err := p.Resize(int(cols), int(rows)); err != nil {
+		p.Close()
+		return nil, fmt.Errorf("failed to resize PTY: %w", err)
 	}
 
-	cmd := exec.Command(shell, "-l")
-	cmd.Dir = workDir
 	env := append(os.Environ(), "TERM=xterm-256color")
 	if m.envFunc != nil {
 		env = append(env, m.envFunc(sessionID)...)
 	}
+
+	cmd := p.Command(shell, "-l")
+	cmd.Dir = workDir
 	cmd.Env = env
 
-	ptmx, err := pty.StartWithSize(cmd, &pty.Winsize{Cols: cols, Rows: rows})
-	if err != nil {
+	if err := cmd.Start(); err != nil {
+		p.Close()
 		return nil, fmt.Errorf("failed to start PTY: %w", err)
 	}
 
+	closeSlave(p)
+
 	sess := &Session{
 		id:         sessionID,
+		pty:        p,
 		cmd:        cmd,
-		ptyF:       ptmx,
 		scrollback: NewRingBuffer(scrollbackSize),
 		done:       make(chan struct{}),
 	}
@@ -285,28 +319,38 @@ func (m *Manager) CreateWithCommand(sessionID, workDir string, cols, rows uint16
 		delete(m.sessions, sessionID)
 	}
 
-	shell := os.Getenv("SHELL")
-	if shell == "" {
-		shell = "/bin/sh"
+	shell := defaultShell()
+
+	p, err := gopty.New()
+	if err != nil {
+		return nil, fmt.Errorf("failed to create PTY: %w", err)
+	}
+
+	if err := p.Resize(int(cols), int(rows)); err != nil {
+		p.Close()
+		return nil, fmt.Errorf("failed to resize PTY: %w", err)
 	}
 
-	cmd := exec.Command(shell, "-l", "-c", command)
-	cmd.Dir = workDir
 	env := append(os.Environ(), "TERM=xterm-256color")
 	if m.envFunc != nil {
 		env = append(env, m.envFunc(sessionID)...)
 	}
+
+	cmd := p.Command(shell, "-l", "-c", command)
+	cmd.Dir = workDir
 	cmd.Env = env
 
-	ptmx, err := pty.StartWithSize(cmd, &pty.Winsize{Cols: cols, Rows: rows})
-	if err != nil {
+	if err := cmd.Start(); err != nil {
+		p.Close()
 		return nil, fmt.Errorf("failed to start PTY: %w", err)
 	}
 
+	closeSlave(p)
+
 	sess := &Session{
 		id:         sessionID,
+		pty:        p,
 		cmd:        cmd,
-		ptyF:       ptmx,
 		scrollback: NewRingBuffer(scrollbackSize),
 		done:       make(chan struct{}),
 	}