Avoid panic when push messages are empty or nil (#13751)

app/notification_push.go

@@ -78,13 +78,35 @@ func (a *App) sendPushNotificationToAllSessions(msg *model.PushNotification, use
 		return err
 	}
 
+	if msg == nil {
+		return model.NewAppError(
+			"pushNotification",
+			"api.push_notifications.message.parse.app_error",
+			nil,
+			"",
+			http.StatusBadRequest,
+		)
+	}
+
+	notification, parseError := model.PushNotificationFromJson(strings.NewReader(msg.ToJson()))
+	if parseError != nil {
+		return model.NewAppError(
+			"pushNotification",
+			"api.push_notifications.message.parse.app_error",
+			nil,
+			parseError.Error(),
+			http.StatusInternalServerError,
+		)
+	}
+
 	for _, session := range sessions {
 		// Don't send notifications to this session if it's expired or we want to skip it
 		if session.IsExpired() || (skipSessionId != "" && skipSessionId == session.Id) {
 			continue
 		}
 
-		tmpMessage := model.PushNotificationFromJson(strings.NewReader(msg.ToJson()))
+		// We made a copy to avoid decoding and parsing all the time
+		tmpMessage := notification
 		tmpMessage.SetDeviceIdAndPlatform(session.DeviceId)
 		tmpMessage.AckId = model.NewId()
 

app/notification_push_test.go

@@ -955,3 +955,22 @@ func TestBuildPushNotificationMessageMentions(t *testing.T) {
 		})
 	}
 }
+
+func TestSendPushNotifications(t *testing.T) {
+	th := Setup(t).InitBasic()
+	th.App.CreateSession(&model.Session{
+		UserId:    th.BasicUser.Id,
+		DeviceId:  "test",
+		ExpiresAt: model.GetMillis() + 100000,
+	})
+	defer th.TearDown()
+
+	t.Run("should return error if data is not valid or nil", func(t *testing.T) {
+		err := th.App.sendPushNotificationToAllSessions(nil, th.BasicUser.Id, "")
+		assert.NotNil(t, err)
+		assert.Equal(t, "pushNotification: An error occurred building the push notification message, ", err.Error())
+		// Errors derived of using an empty object are handled internally through the notifications log
+		err = th.App.sendPushNotificationToAllSessions(&model.PushNotification{}, th.BasicUser.Id, "")
+		assert.Nil(t, err)
+	})
+}