salix/modules/ticket/back/models/ticket-service.js

const UserError = require('vn-loopback/util/user-error');

module.exports = Self => {
    Self.observe('before save', async ctx => {
        const models = Self.app.models;
        const changes = ctx.currentInstance || ctx.instance;

        if (changes && !ctx.isNewInstance) {
            const ticketId = changes.ticketFk;
            const isLocked = await models.Ticket.isLocked(ticketId);
            if (isLocked)
                throw new UserError(`The current ticket can't be modified`);

            const isRefund = await models.TicketRefund.findOne({
                where: {refundTicketFk: ticketId}
            }, {
                transaction: ctx.options.transaction
            });

            if (isRefund && ctx.data && Object.keys(ctx.data).some(field => field !== 'ticketServiceTypeFk'))
                throw new UserError('Only description can be modified in refund tickets');
        }

        if (changes?.ticketServiceTypeFk) {
            const ticketServiceType = await models.TicketServiceType.findById(changes.ticketServiceTypeFk);
            changes.description = ticketServiceType.name;
        }
    });

    Self.observe('before delete', async ctx => {
        const models = Self.app.models;
        const service = await models.TicketService.findById(ctx.where.id);
        const isLocked = await models.Ticket.isLocked(service.ticketFk);

        if (isLocked)
            throw new UserError(`The current ticket can't be modified`);
    });
};