salix/services/loopback/common/methods/vn-model/rewriteDbError.js

module.exports = Self => {
    /**
     * Catches database errors overriding
     * model.create() and model.upsert() methods
     * @param {Object} replaceErrFunc - Callback
     */
    Self.rewriteDbError = function(replaceErrFunc) {
        this.once('attached', () => {
            let realUpsert = this.upsert;
            this.upsert = async(data, options, cb) => {
                if (options instanceof Function) {
                    cb = options;
                    options = null;
                }

                try {
                    await realUpsert.call(this, data, options);
                    if (cb) cb();
                } catch (err) {
                    let myErr = replaceErr(err, replaceErrFunc);
                    if (cb)
                        cb(myErr);
                    else
                        throw myErr;
                }
            };

            let realCreate = this.create;
            this.create = async(data, options, cb) => {
                if (options instanceof Function) {
                    cb = options;
                    options = null;
                }

                try {
                    await realCreate.call(this, data, options);
                    if (cb) cb();
                } catch (err) {
                    let myErr = replaceErr(err, replaceErrFunc);
                    if (cb)
                        cb(myErr);
                    else
                        throw myErr;
                }
            };
        });
    };

    function replaceErr(err, replaceErrFunc) {
        if (Array.isArray(err)) {
            let errs = [];
            for (let e of err)
                errs.push(replaceErrFunc(e));
            return errs;
        }
        return replaceErrFunc(err);
    }
};