planka_custom/server/api/helpers/notifications/create-one.js

const valuesValidator = (value) => {
  if (!_.isPlainObject(value)) {
    return false;
  }

  if (!_.isPlainObject(value.user) && !_.isString(value.userId)) {
    return false;
  }

  if (!_.isPlainObject(value.action)) {
    return false;
  }

  return true;
};

module.exports = {
  inputs: {
    values: {
      type: 'ref',
      custom: valuesValidator,
      required: true,
    },
  },

  async fn(inputs) {
    const { values } = inputs;

    if (values.user) {
      values.userId = values.user.id;
    }

    const notification = await Notification.create({
      ...values,
      actionId: values.action.id,
      cardId: values.action.cardId,
    }).fetch();

    sails.sockets.broadcast(`user:${notification.userId}`, 'notificationCreate', {
      item: notification,
    });

    return notification;
  },
};