fix(daemon): surface dropped input

writeToPane logged pty write failures but the user's keystrokes just
vanished. Notify on failure so a wedged pty or dead child surfaces as
a NoticeInputDropped toast; coalescing collapses repeated failures on
the same code into one toast with a rising count instead of spamming.

commit: a2b1d8632d117998a03e341b11f1ae2148cffb0b
author: brice · 3mo ago · 2026-07-21 04:56 UTC
parent: 0f2b5db
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

3 files · +49 -0

M internal/usecase/daemon/daemon_test.go +20 -0


@@ -105,6 +105,26 @@ func newBlockingPTYWithWrites(t testing.T, writes chan<- []byte) (portsmocks.M
105	105		return p, unblock
106	106		}
107	107
	108	+	// newBlockingPTYWithFailingWrite returns a MockPTY whose Write always fails
	109	+	// with writeErr, simulating a wedged pty (or a dead child) that cannot
	110	+	// accept forwarded keystrokes.
	111	+	func newBlockingPTYWithFailingWrite(t testing.T, writeErr error) (portsmocks.MockPTY, func()) {
	112	+	t.Helper()
	113	+	p := portsmocks.NewMockPTY(t)
	114	+	release := make(chan struct{})
	115	+	var once sync.Once
	116	+	unblock := func() { once.Do(func() { close(release) }) }
	117	+	p.EXPECT().Read(mock.Anything).RunAndReturn(func(b []byte) (int, error) {
	118	+	<-release
	119	+	return 0, io.EOF
	120	+	}).Maybe()
	121	+	p.EXPECT().Write(mock.Anything).Return(0, writeErr).Maybe()
	122	+	p.EXPECT().Resize(mock.Anything).Return(nil).Maybe()
	123	+	p.EXPECT().Close().RunAndReturn(func() error { unblock(); return nil }).Maybe()
	124	+	p.EXPECT().Pid().Return(4242).Maybe()
	125	+	return p, unblock
	126	+	}
	127	+
108	128		// quietPTY is an independently closable PTY for background floating prewarms.
109	129		// It intentionally has no testify expectations: tests using the factories below
110	130		// are asserting their regular panes, not incidental asynchronous prewarms.


@@ -105,6 +105,26 @@ func newBlockingPTYWithWrites(t testing.T, writes chan<- []byte) (portsmocks.M
105	return p, unblock	105		return p, unblock
106	}	106		}
107		107
		108	+	// newBlockingPTYWithFailingWrite returns a MockPTY whose Write always fails
		109	+	// with writeErr, simulating a wedged pty (or a dead child) that cannot
		110	+	// accept forwarded keystrokes.
		111	+	func newBlockingPTYWithFailingWrite(t testing.T, writeErr error) (portsmocks.MockPTY, func()) {
		112	+	t.Helper()
		113	+	p := portsmocks.NewMockPTY(t)
		114	+	release := make(chan struct{})
		115	+	var once sync.Once
		116	+	unblock := func() { once.Do(func() { close(release) }) }
		117	+	p.EXPECT().Read(mock.Anything).RunAndReturn(func(b []byte) (int, error) {
		118	+	<-release
		119	+	return 0, io.EOF
		120	+	}).Maybe()
		121	+	p.EXPECT().Write(mock.Anything).Return(0, writeErr).Maybe()
		122	+	p.EXPECT().Resize(mock.Anything).Return(nil).Maybe()
		123	+	p.EXPECT().Close().RunAndReturn(func() error { unblock(); return nil }).Maybe()
		124	+	p.EXPECT().Pid().Return(4242).Maybe()
		125	+	return p, unblock
		126	+	}
		127	+
108	// quietPTY is an independently closable PTY for background floating prewarms.	128		// quietPTY is an independently closable PTY for background floating prewarms.
109	// It intentionally has no testify expectations: tests using the factories below	129		// It intentionally has no testify expectations: tests using the factories below
110	// are asserting their regular panes, not incidental asynchronous prewarms.	130		// are asserting their regular panes, not incidental asynchronous prewarms.

M internal/usecase/daemon/input.go +3 -0


@@ -5,6 +5,7 @@ import (
5	5		"bytes"
6	6		"strconv"
7	7
	8	+	"github.com/bnema/vev/internal/domain"
8	9		"github.com/bnema/vev/internal/usecase/keys"
9	10		"github.com/bnema/vev/internal/usecase/layout"
10	11		"github.com/bnema/vev/internal/usecase/mouse"

@@ -212,6 +213,8 @@ func (d Daemon) writeToPane(sess session, p *pane, data []byte) {
212	213		sess.mu.Unlock()
213	214		}
214	215		d.log.Error("pty write failed", "err", err, "session", name)
	216	+	d.notify(sess, domain.NoticeError, domain.NoticeInputDropped,
	217	+	"input not delivered to pane", err)
215	218		}
216	219		}
217	220


@@ -5,6 +5,7 @@ import (
5	"bytes"	5		"bytes"
6	"strconv"	6		"strconv"
7		7
		8	+	"github.com/bnema/vev/internal/domain"
8	"github.com/bnema/vev/internal/usecase/keys"	9		"github.com/bnema/vev/internal/usecase/keys"
9	"github.com/bnema/vev/internal/usecase/layout"	10		"github.com/bnema/vev/internal/usecase/layout"
10	"github.com/bnema/vev/internal/usecase/mouse"	11		"github.com/bnema/vev/internal/usecase/mouse"

@@ -212,6 +213,8 @@ func (d Daemon) writeToPane(sess session, p *pane, data []byte) {
212	sess.mu.Unlock()	213		sess.mu.Unlock()
213	}	214		}
214	d.log.Error("pty write failed", "err", err, "session", name)	215		d.log.Error("pty write failed", "err", err, "session", name)
		216	+	d.notify(sess, domain.NoticeError, domain.NoticeInputDropped,
		217	+	"input not delivered to pane", err)
215	}	218		}
216	}	219		}
217		220

M internal/usecase/daemon/input_test.go +26 -0


@@ -3,6 +3,7 @@ package daemon
3	3		import (
4	4		"context"
5	5		"encoding/base64"
	6	+	"errors"
6	7		"fmt"
7	8		"strings"
8	9		"sync"

@@ -172,6 +173,31 @@ func TestAltCForwardsToPTY(t *testing.T) {
172	173		releasePTY()
173	174		}
174	175
	176	+	// TestWriteToPaneFailureNotifiesDroppedInput drives forwarded keystrokes into
	177	+	// a pane whose pty.Write always fails (a wedged pty, or a dead child). The
	178	+	// user's typing must not silently vanish: each failed write records a
	179	+	// NoticeInputDropped notice, and repeated failures on the same code coalesce
	180	+	// into a single toast with a rising count rather than spamming one per key.
	181	+	func TestWriteToPaneFailureNotifiesDroppedInput(t *testing.T) {
	182	+	writeErr := errors.New("write /dev/ptmx: input/output error")
	183	+	p, releasePTY := newBlockingPTYWithFailingWrite(t, writeErr)
	184	+	defer releasePTY()
	185	+	d, sess, ac, _ := newManualSessionWithPTYs(t, p)
	186	+
	187	+	for range 5 {
	188	+	d.handleInput(sess, ac, []byte("x"))
	189	+	}
	190	+
	191	+	toasts := awaitToastCount(t, ac, 1)
	192	+	require.Equal(t, domain.NoticeInputDropped, toasts[0].Code)
	193	+	require.Equal(t, domain.NoticeError, toasts[0].Severity)
	194	+	require.Equal(t, "input not delivered to pane", toasts[0].Message)
	195	+	require.Equal(t, 5, toasts[0].Count, "5 failed writes must coalesce into one toast, not one per keystroke")
	196	+
	197	+	hist := d.notices.history()
	198	+	require.Len(t, hist, 5, "coalescing is display-only; history keeps every occurrence")
	199	+	}
	200	+
175	201		func TestAltFToggleRetainedFloatingPaneRepaintsImmediately(t *testing.T) {
176	202		normal, releaseNormal := newBlockingPTY(t)
177	203		floatingPTY, releaseFloating := newBlockingPTY(t)


@@ -3,6 +3,7 @@ package daemon
3	import (	3		import (
4	"context"	4		"context"
5	"encoding/base64"	5		"encoding/base64"
		6	+	"errors"
6	"fmt"	7		"fmt"
7	"strings"	8		"strings"
8	"sync"	9		"sync"

@@ -172,6 +173,31 @@ func TestAltCForwardsToPTY(t *testing.T) {
172	releasePTY()	173		releasePTY()
173	}	174		}
174		175
		176	+	// TestWriteToPaneFailureNotifiesDroppedInput drives forwarded keystrokes into
		177	+	// a pane whose pty.Write always fails (a wedged pty, or a dead child). The
		178	+	// user's typing must not silently vanish: each failed write records a
		179	+	// NoticeInputDropped notice, and repeated failures on the same code coalesce
		180	+	// into a single toast with a rising count rather than spamming one per key.
		181	+	func TestWriteToPaneFailureNotifiesDroppedInput(t *testing.T) {
		182	+	writeErr := errors.New("write /dev/ptmx: input/output error")
		183	+	p, releasePTY := newBlockingPTYWithFailingWrite(t, writeErr)
		184	+	defer releasePTY()
		185	+	d, sess, ac, _ := newManualSessionWithPTYs(t, p)
		186	+
		187	+	for range 5 {
		188	+	d.handleInput(sess, ac, []byte("x"))
		189	+	}
		190	+
		191	+	toasts := awaitToastCount(t, ac, 1)
		192	+	require.Equal(t, domain.NoticeInputDropped, toasts[0].Code)
		193	+	require.Equal(t, domain.NoticeError, toasts[0].Severity)
		194	+	require.Equal(t, "input not delivered to pane", toasts[0].Message)
		195	+	require.Equal(t, 5, toasts[0].Count, "5 failed writes must coalesce into one toast, not one per keystroke")
		196	+
		197	+	hist := d.notices.history()
		198	+	require.Len(t, hist, 5, "coalescing is display-only; history keeps every occurrence")
		199	+	}
		200	+
175	func TestAltFToggleRetainedFloatingPaneRepaintsImmediately(t *testing.T) {	201		func TestAltFToggleRetainedFloatingPaneRepaintsImmediately(t *testing.T) {
176	normal, releaseNormal := newBlockingPTY(t)	202		normal, releaseNormal := newBlockingPTY(t)
177	floatingPTY, releaseFloating := newBlockingPTY(t)	203		floatingPTY, releaseFloating := newBlockingPTY(t)