fix(telegram): tolerate empty webhook delete response

cmd/openai-status-bot/main.go

@@ -2,7 +2,9 @@ package main
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
+	"fmt"
 	"log/slog"
 	"net/http"
 	"os"
@@ -13,6 +15,7 @@ import (
 	"time"
 
 	tgbot "github.com/go-telegram/bot"
+	tgmodels "github.com/go-telegram/bot/models"
 	"github.com/tiennm99/openai-status-bot/internal/bot"
 	"github.com/tiennm99/openai-status-bot/internal/config"
 	"github.com/tiennm99/openai-status-bot/internal/health"
@@ -24,6 +27,11 @@ import (
 	"go.mongodb.org/mongo-driver/v2/mongo/options"
 )
 
+type telegramWebhookManager interface {
+	DeleteWebhook(context.Context, *tgbot.DeleteWebhookParams) (bool, error)
+	GetWebhookInfo(context.Context) (*tgmodels.WebhookInfo, error)
+}
+
 func main() {
 	cfg, err := config.LoadFromEnv()
 	if err != nil {
@@ -103,7 +111,7 @@ func main() {
 		os.Exit(1)
 	}
 	requestCtx, cancelRequest := contextWithOptionalTimeout(ctx, cfg.HTTPTimeout)
-	_, err = telegramBot.DeleteWebhook(requestCtx, &tgbot.DeleteWebhookParams{DropPendingUpdates: false})
+	err = clearTelegramWebhook(requestCtx, telegramBot)
 	cancelRequest()
 	if err != nil {
 		logger.Error("delete telegram webhook", "error", redactTelegramRuntimeError(cfg.TelegramBotToken, err))
@@ -163,3 +171,33 @@ func frameworkInitialOffset(nextOffset int64) (int64, bool) {
 	}
 	return nextOffset - 1, true
 }
+
+func clearTelegramWebhook(ctx context.Context, telegramBot telegramWebhookManager) error {
+	_, err := telegramBot.DeleteWebhook(ctx, &tgbot.DeleteWebhookParams{DropPendingUpdates: false})
+	if err == nil {
+		return nil
+	}
+	if !isDeleteWebhookEmptyResponseError(err) {
+		return err
+	}
+
+	info, infoErr := telegramBot.GetWebhookInfo(ctx)
+	if infoErr != nil {
+		return fmt.Errorf("deleteWebhook returned an empty response and getWebhookInfo failed: %w", errors.Join(err, infoErr))
+	}
+	if info == nil {
+		return fmt.Errorf("deleteWebhook returned an empty response and getWebhookInfo returned no webhook info: %w", err)
+	}
+	if info.URL != "" {
+		return fmt.Errorf("deleteWebhook returned an empty response and webhook is still configured: %w", err)
+	}
+	return nil
+}
+
+func isDeleteWebhookEmptyResponseError(err error) bool {
+	var syntaxErr *json.SyntaxError
+	if !errors.As(err, &syntaxErr) {
+		return false
+	}
+	return strings.Contains(err.Error(), "error decode response body for method deleteWebhook, ,")
+}

cmd/openai-status-bot/main_test.go

@@ -1,6 +1,16 @@
 package main
 
-import "testing"
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+	"testing"
+
+	tgbot "github.com/go-telegram/bot"
+	tgmodels "github.com/go-telegram/bot/models"
+)
 
 func TestFrameworkInitialOffsetSeedsLastSeenUpdate(t *testing.T) {
 	tests := []struct {
@@ -23,3 +33,95 @@ func TestFrameworkInitialOffsetSeedsLastSeenUpdate(t *testing.T) {
 		})
 	}
 }
+
+func TestClearTelegramWebhookReturnsNilOnSuccessfulDelete(t *testing.T) {
+	manager := &fakeWebhookManager{}
+
+	if err := clearTelegramWebhook(context.Background(), manager); err != nil {
+		t.Fatalf("clearTelegramWebhook returned error: %v", err)
+	}
+	if manager.deleteCalls != 1 || manager.infoCalls != 0 {
+		t.Fatalf("calls = delete %d info %d, want delete 1 info 0", manager.deleteCalls, manager.infoCalls)
+	}
+}
+
+func TestClearTelegramWebhookAcceptsEmptyDeleteResponseWhenWebhookGone(t *testing.T) {
+	manager := &fakeWebhookManager{
+		deleteErr:   emptyDeleteWebhookResponseError(t),
+		webhookInfo: &tgmodels.WebhookInfo{},
+	}
+
+	if err := clearTelegramWebhook(context.Background(), manager); err != nil {
+		t.Fatalf("clearTelegramWebhook returned error: %v", err)
+	}
+	if manager.deleteCalls != 1 || manager.infoCalls != 1 {
+		t.Fatalf("calls = delete %d info %d, want delete 1 info 1", manager.deleteCalls, manager.infoCalls)
+	}
+}
+
+func TestClearTelegramWebhookFailsWhenWebhookStillConfiguredAfterEmptyDeleteResponse(t *testing.T) {
+	manager := &fakeWebhookManager{
+		deleteErr:   emptyDeleteWebhookResponseError(t),
+		webhookInfo: &tgmodels.WebhookInfo{URL: "https://example.com/webhook"},
+	}
+
+	err := clearTelegramWebhook(context.Background(), manager)
+	if err == nil || !strings.Contains(err.Error(), "webhook is still configured") {
+		t.Fatalf("error = %v, want webhook still configured", err)
+	}
+}
+
+func TestClearTelegramWebhookFailsWhenWebhookInfoCheckFails(t *testing.T) {
+	infoErr := errors.New("getWebhookInfo unavailable")
+	manager := &fakeWebhookManager{
+		deleteErr:      emptyDeleteWebhookResponseError(t),
+		webhookInfoErr: infoErr,
+	}
+
+	err := clearTelegramWebhook(context.Background(), manager)
+	if !errors.Is(err, infoErr) {
+		t.Fatalf("error = %v, want wrapping info error", err)
+	}
+}
+
+func TestClearTelegramWebhookReturnsNonEmptyDeleteError(t *testing.T) {
+	deleteErr := errors.New("telegram unauthorized")
+	manager := &fakeWebhookManager{deleteErr: deleteErr}
+
+	err := clearTelegramWebhook(context.Background(), manager)
+	if !errors.Is(err, deleteErr) {
+		t.Fatalf("error = %v, want delete error", err)
+	}
+	if manager.infoCalls != 0 {
+		t.Fatalf("infoCalls = %d, want 0", manager.infoCalls)
+	}
+}
+
+type fakeWebhookManager struct {
+	deleteErr      error
+	webhookInfo    *tgmodels.WebhookInfo
+	webhookInfoErr error
+	deleteCalls    int
+	infoCalls      int
+}
+
+func (f *fakeWebhookManager) DeleteWebhook(context.Context, *tgbot.DeleteWebhookParams) (bool, error) {
+	f.deleteCalls++
+	return f.deleteErr == nil, f.deleteErr
+}
+
+func (f *fakeWebhookManager) GetWebhookInfo(context.Context) (*tgmodels.WebhookInfo, error) {
+	f.infoCalls++
+	return f.webhookInfo, f.webhookInfoErr
+}
+
+func emptyDeleteWebhookResponseError(t *testing.T) error {
+	t.Helper()
+
+	var response struct{}
+	err := json.Unmarshal([]byte{}, &response)
+	if err == nil {
+		t.Fatal("expected json decode error")
+	}
+	return fmt.Errorf("error decode response body for method deleteWebhook, , %w", err)
+}