Fix PTY workdir and process group teardown

internal/pty/pty_test.go

@@ -0,0 +1,84 @@
+package pty
+
+import (
+	"bytes"
+	"errors"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func TestStartUsesWorkDir(t *testing.T) {
+	dir := t.TempDir()
+	p, err := Start([]string{"sh", "-c", "pwd"}, nil, dir, 80, 24)
+	if err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	defer p.Close()
+
+	var out bytes.Buffer
+	buf := make([]byte, 256)
+	deadline := time.Now().Add(5 * time.Second)
+	for time.Now().Before(deadline) {
+		n, err := p.Read(buf)
+		if n > 0 {
+			out.Write(buf[:n])
+			if strings.Contains(out.String(), dir) {
+				break
+			}
+		}
+		if err != nil {
+			break
+		}
+	}
+	_ = p.Wait()
+
+	if got := strings.TrimSpace(out.String()); got != dir {
+		t.Fatalf("pwd output = %q, want %q", got, dir)
+	}
+}
+
+func TestCloseKillsProcessGroup(t *testing.T) {
+	dir := t.TempDir()
+	pidFile := filepath.Join(dir, "sleep.pid")
+	env := append(os.Environ(), "PIDFILE="+pidFile)
+	p, err := Start([]string{"sh", "-c", "sleep 30 & echo $! > \"$PIDFILE\"; wait"}, env, "", 80, 24)
+	if err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	deadline := time.Now().Add(5 * time.Second)
+	var childPID int
+	for time.Now().Before(deadline) {
+		b, err := os.ReadFile(pidFile)
+		if err == nil {
+			childPID, _ = strconv.Atoi(strings.TrimSpace(string(b)))
+			if childPID > 0 {
+				break
+			}
+		}
+		time.Sleep(20 * time.Millisecond)
+	}
+	if childPID <= 0 {
+		_ = p.Close()
+		t.Fatalf("background child pid was not written")
+	}
+
+	if err := p.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+	_ = p.Wait()
+
+	deadline = time.Now().Add(5 * time.Second)
+	for time.Now().Before(deadline) {
+		err := syscall.Kill(childPID, 0)
+		if errors.Is(err, syscall.ESRCH) {
+			return
+		}
+		time.Sleep(20 * time.Millisecond)
+	}
+	t.Fatalf("background child pid %d still exists after PTY.Close", childPID)
+}