1 files changed, 290 insertions, 0 deletions
diff --git a/internal/testsuite/testsuite.go b/internal/testsuite/testsuite.go
new file mode 100644
index 00000000..456c36b4
--- /dev/null
+++ b/internal/testsuite/testsuite.go
@@ -0,0 +1,290 @@
+// Package testsuite provides many quick-and-dirty integration testing utilities.
+//
+// Attempting to import this package outside testing causes the resulting
+// program to panic.
+package testsuite
+
+import (
+	"bufio"
+	"context"
+	"crypto/sha512"
+	"errors"
+	"log"
+	"os"
+	"os/exec"
+	"os/signal"
+	"sync"
+	"syscall"
+	"time"
+)
+
+// ReceiveSignals blocks until a termination signal arrives, and terminates.
+func ReceiveSignals() {
+	s := make(chan os.Signal, 3)
+	signal.Notify(s, os.Interrupt, syscall.SIGTERM, syscall.SIGHUP)
+	log.Fatalf("terminating on signal %s", <-s)
+}
+
+// MustRun runs command and terminates the testsuite on error.
+func MustRun(cred *syscall.Credential, extraEnv []string, command ...string) {
+	cmd := exec.Command(command[0], command[1:]...)
+	cmd.Stdout, cmd.Stderr = os.Stdout, os.Stderr
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		Pdeathsig:  syscall.SIGKILL,
+		Credential: cred,
+	}
+	if len(extraEnv) != 0 {
+		cmd.Env = append(cmd.Environ(), extraEnv...)
+	}
+	if err := cmd.Run(); err != nil {
+		log.Fatal(err)
+	}
+}
+
+// ErrUnexpectedSuccess is returned for processes expected to exit with a
+// non-zero code, but failed to do so.
+var ErrUnexpectedSuccess = errors.New("process unexpectedly exited with code 0")
+
+// MustFail runs command and terminates the testsuite if the program fails to
+// start or exits with code 0.
+func MustFail(cred *syscall.Credential, extraEnv []string, command ...string) {
+	cmd := exec.Command(command[0], command[1:]...)
+	cmd.Stdout, cmd.Stderr = os.Stdout, os.Stderr
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		Pdeathsig:  syscall.SIGKILL,
+		Credential: cred,
+	}
+	if len(extraEnv) != 0 {
+		cmd.Env = append(cmd.Environ(), extraEnv...)
+	}
+	if err := cmd.Run(); err == nil {
+		log.Fatal(ErrUnexpectedSuccess)
+	} else if e, ok := errors.AsType[*exec.ExitError](err); !ok {
+		log.Fatal(err)
+	} else if !e.Exited() {
+		log.Fatal(e)
+	}
+}
+
+// MustStart starts cmd and returns a channel delivering its wait error.
+func MustStart(cmd *exec.Cmd) (done <-chan error) {
+	if err := cmd.Start(); err != nil {
+		log.Fatal(err)
+	}
+	d := make(chan error)
+	go func() { d <- cmd.Wait() }()
+	return d
+}
+
+// MustStartWith wraps [MustStart] and creates the [exec.Cmd] object internally.
+func MustStartWith(
+	ctx context.Context,
+	cred *syscall.Credential,
+	extraEnv []string,
+	files []*os.File,
+	command ...string,
+) (proc *os.Process, done <-chan error) {
+	cmd := exec.CommandContext(ctx, command[0], command[1:]...)
+	cmd.Stdout, cmd.Stderr = os.Stdout, os.Stderr
+	cmd.ExtraFiles = files
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		Pdeathsig:  syscall.SIGTERM,
+		Credential: cred,
+	}
+	if len(extraEnv) != 0 {
+		cmd.Env = append(cmd.Environ(), extraEnv...)
+	}
+	return cmd.Process, MustStart(cmd)
+}
+
+// MustCheckFilter is like [CheckFilter], but terminates the test suite if a
+// non-nil error is returned. Otherwise, the tracee is terminated after it
+// resumes.
+func MustCheckFilter(pid int, sum [sha512.Size]byte) {
+	// podman installs its own filter
+	if err := CheckFilter(pid, 1, sum); err != nil {
+		log.Fatal(err)
+	} else if err = syscall.Kill(pid, syscall.SIGTERM); err != nil {
+		log.Fatalf("cannot terminate tracee: %v", err)
+	}
+}
+
+// FilterTerminated returns a non-nil error if err is not an [exec.ExitError]
+// describing a process terminated by a syscall.SIGTERM signal.
+func FilterTerminated(err error) error {
+	if err == nil {
+		return ErrUnexpectedSuccess
+	}
+
+	e, ok := errors.AsType[*exec.ExitError](err)
+	if !ok {
+		return err
+	}
+
+	if e.ExitCode() == 0x80+int(syscall.SIGTERM) {
+		return nil
+	}
+	return e
+}
+
+// Poll repeatedly runs command until it succeeds.
+func Poll(
+	d time.Duration,
+	cred *syscall.Credential,
+	extraEnv []string,
+	command ...string,
+) {
+	for range time.NewTicker(d).C {
+		cmd := exec.Command(command[0], command[1:]...)
+		cmd.SysProcAttr = &syscall.SysProcAttr{
+			Pdeathsig:  syscall.SIGKILL,
+			Credential: cred,
+		}
+		if len(extraEnv) != 0 {
+			cmd.Env = append(cmd.Environ(), extraEnv...)
+		}
+		if err := cmd.Run(); err != nil {
+			if e, ok := errors.AsType[*exec.ExitError](err); ok && e.Exited() {
+				continue
+			}
+			log.Fatal(err)
+		}
+		break
+	}
+}
+
+const (
+	// XDGRuntimeDir is the hardcoded XDG runtime directory for the user
+	// described by [GetUser].
+	XDGRuntimeDir = "/var/run/user/1000"
+
+	// XDGRuntimeEnv is the environment variable string for XDG_RUNTIME_DIR.
+	XDGRuntimeEnv = "XDG_RUNTIME_DIR=" + XDGRuntimeDir
+)
+
+// MustStartSessionBus starts a session bus that is never explicitly terminated.
+// The test suite is terminated if the session bus daemon terminates.
+func MustStartSessionBus(cred *syscall.Credential) (dbusEnv string) {
+	r, w, err := os.Pipe()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// this is never explicitly terminated
+	_, done := MustStartWith(
+		context.Background(), cred, nil, []*os.File{w},
+		"dbus-daemon",
+		"--print-address=3",
+		"--address=unix:path="+XDGRuntimeDir+"/dbus",
+		"--session",
+		"--nofork",
+		"--nopidfile",
+	)
+
+	go func() {
+		if _err := <-done; _err != nil {
+			log.Fatal(_err)
+		}
+		log.Fatal("session bus terminated unexpectedly")
+	}()
+
+	dbusEnv, err = bufio.NewReader(r).ReadString('\n')
+	if err != nil {
+		log.Fatal(err)
+	}
+	dbusEnv = dbusEnv[:len(dbusEnv)-1]
+	log.Printf("dbus listening on %s", dbusEnv)
+	dbusEnv = "DBUS_SESSION_BUS_ADDRESS=" + dbusEnv
+
+	if err = r.Close(); err != nil {
+		log.Fatal(err)
+	}
+	return
+}
+
+const (
+	// SwayEnv is the environment variable string for the sway IPC socket.
+	SwayEnv = "SWAYSOCK=" + XDGRuntimeDir + "/sway"
+	// WaylandEnv is the environment variable string for the wayland display.
+	WaylandEnv = "WAYLAND_DISPLAY=wayland-1"
+)
+
+// MustStartSway starts the sway wayland display server which must be terminated
+// by calling [TerminateSway].
+func MustStartSway(
+	wg *sync.WaitGroup,
+	cred *syscall.Credential,
+	dbusEnv string,
+) {
+	wg.Go(func() {
+		// this is terminated via swaymsg
+		_, done := MustStartWith(
+			context.Background(), cred, []string{
+				"WLR_BACKENDS=headless",
+				XDGRuntimeEnv,
+				SwayEnv,
+				dbusEnv,
+			}, nil,
+			"sway",
+		)
+		if err := <-done; err != nil {
+			log.Fatal(err)
+		}
+	})
+
+	Poll(
+		50*time.Millisecond,
+		cred,
+		[]string{SwayEnv},
+		"swaymsg",
+	)
+	log.Printf("sway available via %s", SwayEnv)
+}
+
+// TerminateSway requests for the sway server to terminate via sway IPC.
+func TerminateSway(cred *syscall.Credential) {
+	MustFail(cred, []string{SwayEnv}, "swaymsg", "exit")
+}
+
+// MustStartPipeWire starts a PipeWire server that is never explicitly
+// terminated.  The test suite is terminated if the PipeWire server terminates.
+func MustStartPipeWire(cred *syscall.Credential, dbusEnv string) {
+	// this is never explicitly terminated
+	_, done := MustStartWith(
+		context.Background(), cred, []string{
+			XDGRuntimeEnv,
+			dbusEnv,
+		}, nil,
+		"pipewire",
+	)
+
+	go func() {
+		if _err := <-done; _err != nil {
+			log.Fatal(_err)
+		}
+		log.Fatal("pipewire terminated unexpectedly")
+	}()
+
+	Poll(50*time.Millisecond, cred, []string{
+		XDGRuntimeEnv,
+		dbusEnv,
+	},
+		"wpctl",
+		"status",
+	)
+
+	_, _done := MustStartWith(
+		context.Background(), cred, []string{
+			XDGRuntimeEnv,
+			dbusEnv,
+		}, nil,
+		"wireplumber",
+	)
+
+	go func() {
+		if _err := <-_done; _err != nil {
+			log.Fatal(_err)
+		}
+		log.Fatal("wireplumber terminated unexpectedly")
+	}()
+}