feat(v0.4): add Preflight checks for Layer 1 and Layer 3

2026-04-21 17:09:41 -04:00
parent 77513aa5f8
commit a050b116fa
2 changed files with 361 additions and 0 deletions
@@ -0,0 +1,126 @@
+package session
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"time"
+)
+
+// PreflightOpts configures the Layer-3 + Layer-1 preflight checks that run
+// before session.Run establishes its own lease.
+type PreflightOpts struct {
+	WsDir string
+	Force bool
+	In    io.Reader
+	Out   io.Writer
+}
+
+// PreflightResult reports whether the session should proceed and whether an
+// existing fresh lease is being coexisted-with (in which case Run must NOT
+// write its own lease).
+type PreflightResult struct {
+	Proceed          bool
+	ActiveLeaseFound bool
+}
+
+// Preflight is a convenience wrapper around PreflightFull for callers that
+// only need the proceed/cancel decision.
+func Preflight(opts PreflightOpts) (bool, error) {
+	res, err := PreflightFull(opts)
+	if err != nil {
+		return false, err
+	}
+	return res.Proceed, nil
+}
+
+// PreflightFull runs Layer 3 (stale-workspace) then Layer 1 (active-session).
+// Both warnings are suppressed when Force is true.
+//
+// Missing lease/summary files are the normal first-session case — silent.
+// Corrupt files are removed with an explicit warning. Real I/O errors are
+// surfaced via the returned error.
+func PreflightFull(opts PreflightOpts) (PreflightResult, error) {
+	// --- Layer 3: stale-workspace detection (external modifications) ---
+	if !opts.Force {
+		proceed, err := runStaleWorkspaceCheck(opts)
+		if err != nil {
+			return PreflightResult{}, err
+		}
+		if !proceed {
+			return PreflightResult{Proceed: false}, nil
+		}
+	}
+
+	// --- Layer 1: active-session lease check ---
+	activeLeaseFound, proceed, err := runActiveLeaseCheck(opts)
+	if err != nil {
+		return PreflightResult{}, err
+	}
+	if !proceed {
+		return PreflightResult{Proceed: false}, nil
+	}
+
+	return PreflightResult{Proceed: true, ActiveLeaseFound: activeLeaseFound}, nil
+}
+
+// runStaleWorkspaceCheck returns (proceed, err).
+func runStaleWorkspaceCheck(opts PreflightOpts) (bool, error) {
+	summary, err := ReadSummary(SummaryPath(opts.WsDir))
+	if err != nil {
+		return false, fmt.Errorf("reading last-session summary: %w", err)
+	}
+	if summary == nil {
+		return true, nil
+	}
+
+	diff, err := DetectExternalChanges(opts.WsDir)
+	if err != nil {
+		return false, fmt.Errorf("detecting external changes: %w", err)
+	}
+	if !HasChanges(diff) {
+		return true, nil
+	}
+
+	fmt.Fprint(opts.Out, FormatStaleWarning(summary, diff))
+	return ConfirmYN(opts.In, opts.Out, "", true), nil
+}
+
+// runActiveLeaseCheck returns (activeLeaseFound, proceed, err).
+func runActiveLeaseCheck(opts PreflightOpts) (bool, bool, error) {
+	leasePath := LeasePath(opts.WsDir)
+
+	existing, err := ReadLease(leasePath)
+	switch {
+	case err == nil && existing != nil:
+		if IsFresh(existing, time.Now(), StaleLeaseAfter) {
+			if opts.Force {
+				return true, true, nil
+			}
+			fmt.Fprint(opts.Out, FormatActiveWarning(existing, time.Now()))
+			if !ConfirmYN(opts.In, opts.Out, "", false) {
+				return false, false, nil
+			}
+			return true, true, nil
+		}
+		removed, rmErr := CleanupStaleLease(leasePath, StaleLeaseAfter)
+		if rmErr != nil {
+			fmt.Fprintf(opts.Out, "[ctask] Warning: could not remove stale lease: %v\n", rmErr)
+		} else if removed != nil {
+			fmt.Fprint(opts.Out, FormatStaleCleanupNotice(removed, time.Now()))
+		}
+		return false, true, nil
+
+	case errors.Is(err, os.ErrNotExist):
+		return false, true, nil
+
+	case err != nil:
+		fmt.Fprintf(opts.Out, "[ctask] Warning: unparseable session lease at %s (%v); removing\n", leasePath, err)
+		if rmErr := os.Remove(leasePath); rmErr != nil && !errors.Is(rmErr, os.ErrNotExist) {
+			fmt.Fprintf(opts.Out, "[ctask] Warning: failed to remove corrupt lease: %v\n", rmErr)
+		}
+		return false, true, nil
+	}
+	return false, true, nil
+}
@@ -0,0 +1,235 @@
+package session
+
+import (
+	"bytes"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestPreflightNoPriorSession(t *testing.T) {
+	wsDir := t.TempDir()
+
+	var out bytes.Buffer
+	in := strings.NewReader("")
+	ok, err := Preflight(PreflightOpts{
+		WsDir: wsDir,
+		Force: false,
+		In:    in,
+		Out:   &out,
+	})
+	if err != nil {
+		t.Fatalf("Preflight: %v", err)
+	}
+	if !ok {
+		t.Error("Preflight should proceed on empty workspace")
+	}
+	if out.Len() != 0 {
+		t.Errorf("expected silent preflight, got:\n%s", out.String())
+	}
+}
+
+func TestPreflightStaleWorkspaceYes(t *testing.T) {
+	wsDir := t.TempDir()
+
+	oldTime := time.Date(2026, 4, 21, 10, 0, 0, 0, time.UTC)
+	summary := &SessionSummary{
+		EndedAt:     oldTime,
+		Hostname:    "other-host",
+		Agent:       "claude",
+		EndManifest: []FileEntry{{Path: "notes.md", Size: 5, Mtime: oldTime}},
+	}
+	WriteSummary(SummaryPath(wsDir), summary)
+	os.WriteFile(filepath.Join(wsDir, "notes.md"), []byte("changed content"), 0644)
+
+	var out bytes.Buffer
+	in := strings.NewReader("\n")
+
+	ok, err := Preflight(PreflightOpts{WsDir: wsDir, Force: false, In: in, Out: &out})
+	if err != nil {
+		t.Fatalf("Preflight: %v", err)
+	}
+	if !ok {
+		t.Error("default-yes on stale warning should proceed")
+	}
+	if !strings.Contains(out.String(), "Workspace modified since last session ended") {
+		t.Errorf("expected stale warning, got:\n%s", out.String())
+	}
+}
+
+func TestPreflightStaleWorkspaceNo(t *testing.T) {
+	wsDir := t.TempDir()
+
+	oldTime := time.Date(2026, 4, 21, 10, 0, 0, 0, time.UTC)
+	summary := &SessionSummary{
+		EndedAt:     oldTime,
+		Hostname:    "other-host",
+		Agent:       "claude",
+		EndManifest: []FileEntry{{Path: "notes.md", Size: 5, Mtime: oldTime}},
+	}
+	WriteSummary(SummaryPath(wsDir), summary)
+	os.WriteFile(filepath.Join(wsDir, "notes.md"), []byte("changed content"), 0644)
+
+	var out bytes.Buffer
+	in := strings.NewReader("n\n")
+
+	ok, err := Preflight(PreflightOpts{WsDir: wsDir, Force: false, In: in, Out: &out})
+	if err != nil {
+		t.Fatalf("Preflight: %v", err)
+	}
+	if ok {
+		t.Error(`"n" on stale warning should NOT proceed`)
+	}
+}
+
+func TestPreflightForceSuppressesStaleWarning(t *testing.T) {
+	wsDir := t.TempDir()
+
+	oldTime := time.Date(2026, 4, 21, 10, 0, 0, 0, time.UTC)
+	summary := &SessionSummary{
+		EndedAt:     oldTime,
+		EndManifest: []FileEntry{{Path: "notes.md", Size: 5, Mtime: oldTime}},
+	}
+	WriteSummary(SummaryPath(wsDir), summary)
+	os.WriteFile(filepath.Join(wsDir, "notes.md"), []byte("changed content"), 0644)
+
+	var out bytes.Buffer
+	in := strings.NewReader("")
+
+	ok, err := Preflight(PreflightOpts{WsDir: wsDir, Force: true, In: in, Out: &out})
+	if err != nil {
+		t.Fatalf("Preflight: %v", err)
+	}
+	if !ok {
+		t.Error("Force should bypass the stale warning and proceed")
+	}
+	if strings.Contains(out.String(), "Workspace modified since last session ended") {
+		t.Errorf("Force should suppress stale warning, got:\n%s", out.String())
+	}
+}
+
+func TestPreflightActiveLeaseWarnAccept(t *testing.T) {
+	wsDir := t.TempDir()
+	os.MkdirAll(filepath.Join(wsDir, ".ctask"), 0755)
+
+	now := time.Now().UTC().Truncate(time.Second)
+	fresh := &Lease{
+		SessionID:       "other-host-99-20260421140000",
+		Hostname:        "other-host",
+		Agent:           "claude",
+		Mode:            "local",
+		StartedAt:       now.Add(-10 * time.Minute),
+		LastHeartbeatAt: now.Add(-5 * time.Second),
+	}
+	WriteLease(LeasePath(wsDir), fresh)
+
+	var out bytes.Buffer
+	in := strings.NewReader("y\n")
+
+	res, err := PreflightFull(PreflightOpts{WsDir: wsDir, Force: false, In: in, Out: &out})
+	if err != nil {
+		t.Fatalf("PreflightFull: %v", err)
+	}
+	if !res.Proceed {
+		t.Error(`"y" on active lease should proceed`)
+	}
+	if !res.ActiveLeaseFound {
+		t.Error("ActiveLeaseFound should be true when coexisting with an active lease")
+	}
+	if !strings.Contains(out.String(), "active session") {
+		t.Errorf("expected active-session warning, got:\n%s", out.String())
+	}
+	if _, err := os.Stat(LeasePath(wsDir)); err != nil {
+		t.Errorf("existing lease should remain intact after user confirms: %v", err)
+	}
+}
+
+func TestPreflightForceActiveLeaseCoexists(t *testing.T) {
+	wsDir := t.TempDir()
+	os.MkdirAll(filepath.Join(wsDir, ".ctask"), 0755)
+
+	now := time.Now().UTC().Truncate(time.Second)
+	fresh := &Lease{
+		SessionID:       "other-host-99-20260421140000",
+		Hostname:        "other-host",
+		StartedAt:       now,
+		LastHeartbeatAt: now,
+	}
+	WriteLease(LeasePath(wsDir), fresh)
+
+	var out bytes.Buffer
+	in := strings.NewReader("")
+	res, err := PreflightFull(PreflightOpts{WsDir: wsDir, Force: true, In: in, Out: &out})
+	if err != nil {
+		t.Fatalf("PreflightFull: %v", err)
+	}
+	if !res.Proceed {
+		t.Error("Force must always proceed")
+	}
+	if !res.ActiveLeaseFound {
+		t.Error("Force with fresh lease should still mark ActiveLeaseFound")
+	}
+	if strings.Contains(out.String(), "active session") {
+		t.Errorf("Force should suppress active-session warning, got:\n%s", out.String())
+	}
+	if _, err := os.Stat(LeasePath(wsDir)); err != nil {
+		t.Errorf("existing lease should remain intact under --force: %v", err)
+	}
+}
+
+func TestPreflightStaleLeaseAutoCleans(t *testing.T) {
+	wsDir := t.TempDir()
+	os.MkdirAll(filepath.Join(wsDir, ".ctask"), 0755)
+
+	old := time.Now().Add(-10 * time.Minute).UTC().Truncate(time.Second)
+	stale := &Lease{
+		SessionID:       "other-host-99-20260421100000",
+		Hostname:        "other-host",
+		StartedAt:       old,
+		LastHeartbeatAt: old,
+	}
+	WriteLease(LeasePath(wsDir), stale)
+
+	var out bytes.Buffer
+	in := strings.NewReader("")
+	ok, err := Preflight(PreflightOpts{WsDir: wsDir, Force: false, In: in, Out: &out})
+	if err != nil {
+		t.Fatalf("Preflight: %v", err)
+	}
+	if !ok {
+		t.Error("stale-lease cleanup should proceed automatically")
+	}
+	if !strings.Contains(out.String(), "Cleaned up stale session") {
+		t.Errorf("expected stale-cleanup notice, got:\n%s", out.String())
+	}
+	if _, err := os.Stat(LeasePath(wsDir)); !errors.Is(err, os.ErrNotExist) {
+		t.Errorf("stale lease should be removed, got err=%v", err)
+	}
+}
+
+func TestPreflightCorruptLeaseRemoved(t *testing.T) {
+	wsDir := t.TempDir()
+	os.MkdirAll(filepath.Join(wsDir, ".ctask"), 0755)
+	if err := os.WriteFile(LeasePath(wsDir), []byte("{not json"), 0644); err != nil {
+		t.Fatalf("plant corrupt lease: %v", err)
+	}
+
+	var out bytes.Buffer
+	in := strings.NewReader("")
+	ok, err := Preflight(PreflightOpts{WsDir: wsDir, Force: false, In: in, Out: &out})
+	if err != nil {
+		t.Fatalf("Preflight should not error on corrupt lease: %v", err)
+	}
+	if !ok {
+		t.Error("corrupt lease should be cleaned up and preflight should proceed")
+	}
+	if !strings.Contains(out.String(), "unparseable session lease") {
+		t.Errorf("expected corrupt-lease warning, got:\n%s", out.String())
+	}
+	if _, err := os.Stat(LeasePath(wsDir)); !errors.Is(err, os.ErrNotExist) {
+		t.Errorf("corrupt lease should be removed, got err=%v", err)
+	}
+}