fix(channels): fail fast when all channel startups fail (#2262)

* fix(channels): fail fast when all channel startups fail

* fix(channels): preserve startup errors and cover fail-fast semantics

pkg/channels/manager.go

@@ -12,6 +12,7 @@ import (
 	"fmt"
 	"math"
 	"net/http"
+	"sort"
 	"sync"
 	"time"
 
@@ -513,6 +514,8 @@ func (m *Manager) StartAll(ctx context.Context) error {
 
 	dispatchCtx, cancel := context.WithCancel(ctx)
 	m.dispatchTask = &asyncTask{cancel: cancel}
+	failedStarts := make([]error, 0, len(m.channels))
+	failedNames := make([]string, 0, len(m.channels))
 
 	for name, channel := range m.channels {
 		logger.InfoCF("channels", "Starting channel", map[string]any{
@@ -523,6 +526,8 @@ func (m *Manager) StartAll(ctx context.Context) error {
 				"channel": name,
 				"error":   err.Error(),
 			})
+			failedStarts = append(failedStarts, fmt.Errorf("channel %s: %w", name, err))
+			failedNames = append(failedNames, name)
 			continue
 		}
 		// Lazily create worker only after channel starts successfully
@@ -532,6 +537,36 @@ func (m *Manager) StartAll(ctx context.Context) error {
 		go m.runMediaWorker(dispatchCtx, name, w)
 	}
 
+	if len(m.channels) > 0 && len(m.workers) == 0 {
+		if m.dispatchTask != nil {
+			m.dispatchTask.cancel()
+			m.dispatchTask = nil
+		}
+
+		sort.Strings(failedNames)
+		if len(failedStarts) == 0 {
+			return fmt.Errorf("failed to start any enabled channels")
+		}
+
+		logger.ErrorCF("channels", "All enabled channels failed to start", map[string]any{
+			"failed":          len(failedNames),
+			"total":           len(m.channels),
+			"failed_channels": failedNames,
+		})
+
+		return fmt.Errorf("failed to start any enabled channels: %w", errors.Join(failedStarts...))
+	}
+
+	if len(failedNames) > 0 {
+		sort.Strings(failedNames)
+		logger.WarnCF("channels", "Some channels failed to start", map[string]any{
+			"failed":          len(failedNames),
+			"started":         len(m.workers),
+			"total":           len(m.channels),
+			"failed_channels": failedNames,
+		})
+	}
+
 	// Start the dispatcher that reads from the bus and routes to workers
 	go m.dispatchOutbound(dispatchCtx)
 	go m.dispatchOutboundMedia(dispatchCtx)
@@ -553,7 +588,11 @@ func (m *Manager) StartAll(ctx context.Context) error {
 		}()
 	}
 
-	logger.InfoC("channels", "All channels started")
+	logger.InfoCF("channels", "Channel startup completed", map[string]any{
+		"started": len(m.workers),
+		"failed":  len(failedNames),
+		"total":   len(m.channels),
+	})
 	return nil
 }
 

pkg/channels/manager_test.go

@@ -19,6 +19,8 @@ import (
 type mockChannel struct {
 	BaseChannel
 	sendFn            func(ctx context.Context, msg bus.OutboundMessage) error
+	startFn           func(ctx context.Context) error
+	stopFn            func(ctx context.Context) error
 	sentMessages      []bus.OutboundMessage
 	placeholdersSent  int
 	editedMessages    int
@@ -33,8 +35,19 @@ func (m *mockChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]stri
 	return nil, m.sendFn(ctx, msg)
 }
 
-func (m *mockChannel) Start(ctx context.Context) error { return nil }
-func (m *mockChannel) Stop(ctx context.Context) error  { return nil }
+func (m *mockChannel) Start(ctx context.Context) error {
+	if m.startFn != nil {
+		return m.startFn(ctx)
+	}
+	return nil
+}
+
+func (m *mockChannel) Stop(ctx context.Context) error {
+	if m.stopFn != nil {
+		return m.stopFn(ctx)
+	}
+	return nil
+}
 
 func (m *mockChannel) SendPlaceholder(ctx context.Context, chatID string) (string, error) {
 	m.placeholdersSent++
@@ -86,6 +99,101 @@ func newTestManager() *Manager {
 	return &Manager{
 		channels: make(map[string]Channel),
 		workers:  make(map[string]*channelWorker),
+		bus:      bus.NewMessageBus(),
+	}
+}
+
+func TestStartAll_AllChannelsFail_ReturnsJoinedError(t *testing.T) {
+	m := newTestManager()
+	errA := errors.New("channel-a start failed")
+	errB := errors.New("channel-b start failed")
+
+	m.channels["a"] = &mockChannel{
+		startFn: func(_ context.Context) error { return errA },
+	}
+	m.channels["b"] = &mockChannel{
+		startFn: func(_ context.Context) error { return errB },
+	}
+
+	err := m.StartAll(t.Context())
+	if err == nil {
+		t.Fatal("expected StartAll to fail when all channels fail")
+	}
+	if !strings.Contains(err.Error(), "failed to start any enabled channels") {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if !errors.Is(err, errA) {
+		t.Fatalf("expected error to wrap errA, got: %v", err)
+	}
+	if !errors.Is(err, errB) {
+		t.Fatalf("expected error to wrap errB, got: %v", err)
+	}
+	if len(m.workers) != 0 {
+		t.Fatalf("expected no workers on full startup failure, got %d", len(m.workers))
+	}
+	if m.dispatchTask != nil {
+		t.Fatal("expected dispatch task to be cleared on full startup failure")
+	}
+}
+
+func TestStartAll_PartialFailure_StartsSuccessfulWorkers(t *testing.T) {
+	m := newTestManager()
+	errBad := errors.New("bad channel start failed")
+	processed := make(chan struct{}, 1)
+
+	m.channels["good"] = &mockChannel{
+		sendFn: func(_ context.Context, msg bus.OutboundMessage) error {
+			if msg.Channel == "good" {
+				select {
+				case processed <- struct{}{}:
+				default:
+				}
+			}
+			return nil
+		},
+	}
+	m.channels["bad"] = &mockChannel{
+		startFn: func(_ context.Context) error { return errBad },
+	}
+
+	err := m.StartAll(t.Context())
+	if err != nil {
+		t.Fatalf("expected StartAll to succeed with partial channel failures, got: %v", err)
+	}
+	if len(m.workers) != 1 {
+		t.Fatalf("expected exactly 1 active worker, got %d", len(m.workers))
+	}
+	if _, ok := m.workers["good"]; !ok {
+		t.Fatal("expected worker for successful channel 'good'")
+	}
+	if _, ok := m.workers["bad"]; ok {
+		t.Fatal("did not expect worker for failed channel 'bad'")
+	}
+	if m.dispatchTask == nil {
+		t.Fatal("expected dispatch task to run when at least one channel starts")
+	}
+
+	pubCtx, pubCancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer pubCancel()
+	if err := m.bus.PublishOutbound(pubCtx, bus.OutboundMessage{
+		Channel: "good",
+		ChatID:  "chat-1",
+		Content: "hello",
+	}); err != nil {
+		t.Fatalf("PublishOutbound() error = %v", err)
+	}
+
+	select {
+	case <-processed:
+		// worker processed outbound message as expected
+	case <-time.After(2 * time.Second):
+		t.Fatal("expected successful channel worker to process outbound message")
+	}
+
+	stopCtx, stopCancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer stopCancel()
+	if err := m.StopAll(stopCtx); err != nil {
+		t.Fatalf("StopAll() error = %v", err)
 	}
 }