salix/modules/client/back/models/client-credit.js

module.exports = Self => {
    Self.observe('after save', async ctx => {
        const instance = ctx.instance;
        const models = Self.app.models;

        const clientConfig = await models.ClientConfig.findOne({
            where: {id: 1}
        });
        const maxCreditRows = clientConfig.maxCreditRows;

        const clientCredit = await models.ClientCredit.find({
            where: {clientFk: instance.clientFk},
            order: 'created DESC'
        }, ctx.options);

        if (clientCredit.length > maxCreditRows) {
            const creditToDestroy = [];
            for (const [index, credit] of clientCredit.entries()) {
                if (index >= maxCreditRows)
                    creditToDestroy.push(credit.id);
            }

            await models.ClientCredit.destroyAll({
                id: {inq: creditToDestroy}
            }, ctx.options);
        }
    });
};