How to use the validator.sanitize function in validator

const _hashToUser = function(hash) {
  const user = new User(hash.tenantAlias, hash.principalId, hash.displayName, hash.email, {
    visibility: hash.visibility,
    deleted: hash.deleted,
    locale: hash.locale,
    publicAlias: hash.publicAlias,
    isGlobalAdmin: sanitize(hash['admin:global']).toBooleanStrict(),
    isTenantAdmin: sanitize(hash['admin:tenant']).toBooleanStrict(),
    smallPictureUri: hash.smallPictureUri,
    mediumPictureUri: hash.mediumPictureUri,
    largePictureUri: hash.largePictureUri,
    notificationsUnread: OaeUtil.getNumberParam(hash.notificationsUnread),
    notificationsLastRead: OaeUtil.getNumberParam(hash.notificationsLastRead),
    emailPreference: hash.emailPreference || PrincipalsConfig.getValue(hash.tenantAlias, 'user', 'emailPreference'),
    acceptedTC: OaeUtil.getNumberParam(hash.acceptedTC, 0),
    lastModified: OaeUtil.getNumberParam(hash.lastModified),
    isUserArchive: hash.isUserArchive
  });
  return user;
};

function processAuthorData(data, widgetConfig) {
    if (data.author) {
        var attribs = data.author["@"];

        if (!attribs && typeof data.author === "string") {
            //do not sanitize empty objects {} (must be string)
            widgetConfig.author = sanitize(data.author).trim();
        } else if (data.author["#"]) {
            widgetConfig.author = sanitize(data.author["#"]).trim();
        }

        if (attribs) {
            widgetConfig.authorURL = attribs.href;
            widgetConfig.copyright = attribs["rim:copyright"];
            widgetConfig.authorEmail = attribs.email;
        }
    }
}

if (val || val === 0 || val === "0") {
        switch (field.type) {
            case "text":
                val = addAttr("value", sanitize(val).trim());
                break;

            case "date":
                try {
                    val = DateFormatter(val);
                } catch (e) {
                }
                val = addAttr("value", val);
                break;

            case "hidden":
                val = addAttr("value", sanitize(val.toString()).trim());
                break;

            case "checkbox":
                val = addAttr("checked", "checked");
                break;

            case "radio":
                val = addAttr("checked", "checked");
                break;

            default:
                val = "";
                break;
        }

    }

if (!req.session || !req.session.user) {
        return res.redirect("/login");
    }

    var giftObj = {};
    giftObj.giftId = util.GUID();

    try {
        check(req.body.name).notEmpty();
        check(req.body.categoryId).notEmpty();
        giftObj.name       = sanitize(sanitize(req.body.name).trim()).xss();
        giftObj.categoryId = sanitize(sanitize(req.body.categoryId).trim()).xss();
        giftObj.brand      = sanitize(sanitize(req.body.brand || "").trim()).xss();
        giftObj.unit       = sanitize(sanitize(req.body.unit || "").trim()).xss();
        giftObj.price      = sanitize(sanitize(req.body.price || "").trim()).xss();
        giftObj.expireDate = sanitize(sanitize(req.body.expireDate || "").trim()).xss();
        giftObj.categoryId = sanitize(sanitize(req.body.categoryId).trim()).xss();
    } catch (e) {
        return res.send(resUtil.generateRes(null, config.statusCode.STATUS_INVAILD_PARAMS));
    }

    var ep = EventProxy.create();

    Gift.add(giftObj, function (err, rows) {
        if (err) {
            return ep.emitLater("error", err);
        }

        ep.emitLater("after_addGift");
    });

    ep.once("after_addGift", function () {

function processAuthorData(data, widgetConfig) {
    if (data.author) {
        var attribs = data.author["@"];

        if (!attribs && typeof data.author === "string") {
            //do not sanitize empty objects {} (must be string)
            widgetConfig.author = sanitize(data.author).trim();
        } else if (data.author["#"]) {
            widgetConfig.author = sanitize(data.author["#"]).trim();
        }

        if (attribs) {
            widgetConfig.authorURL = attribs.href;
            widgetConfig.copyright = attribs["rim:copyright"];
            widgetConfig.authorEmail = attribs.email;
        }
    }
}

exports.modification = function (req, res, next) {
    debugCtrller("/controllers/gift/modification");

    if (!req.session || !req.session.user) {
        return res.redirect("/login");
    }

    var giftObj = {};
    try {
        check(req.body.giftId).notEmpty();
        check(req.body.name).notEmpty();
        check(req.body.categoryId).notEmpty();
        giftObj.giftId     = sanitize(sanitize(req.body.giftId).trim()).xss();
        giftObj.name       = sanitize(sanitize(req.body.name).trim()).xss();
        giftObj.categoryId = sanitize(sanitize(req.body.categoryId).trim()).xss();
        giftObj.brand      = sanitize(sanitize(req.body.brand || "").trim()).xss();
        giftObj.unit       = sanitize(sanitize(req.body.unit || "").trim()).xss();
        giftObj.price      = sanitize(sanitize(req.body.price || "").trim()).xss();
        giftObj.expireDate = sanitize(sanitize(req.body.expireDate || "").trim()).xss();
        giftObj.categoryId = sanitize(sanitize(req.body.categoryId).trim()).xss();
    } catch (e) {
        return res.send(resUtil.generateRes(null, config.statusCode.STATUS_INVAILD_PARAMS));
    }

    Gift.modify(giftObj, function (err, rows) {
        if (err) {
            return res.send(resUtil.generateRes(null, err.statusCode));
        }

        return res.send(resUtil.generateRes(null, config.statusCode.STATUS_OK));

function processAuthorData(data, widgetConfig) {
    if (data.author) {
        var attribs = data.author["@"];

        if (!attribs && typeof data.author === "string") {
            //do not sanitize empty objects {} (must be string)
            widgetConfig.author = sanitize(data.author).trim();
        } else if (data.author["#"]) {
            widgetConfig.author = sanitize(data.author["#"]).trim();
        }

        if (attribs) {
            widgetConfig.authorURL = attribs.href;
            widgetConfig.copyright = attribs["rim:copyright"];
            widgetConfig.authorEmail = attribs.email;
        }
    }
}

function processAuthorData(data, widgetConfig) {
    if (data.author) {
        var attribs = data.author["@"];

        if (!attribs && typeof data.author === "string") {
            //do not sanitize empty objects {} (must be string)
            widgetConfig.author = sanitize(data.author).trim();
        } else if (data.author["#"]) {
            widgetConfig.author = sanitize(data.author["#"]).trim();
        }

        if (attribs) {
            widgetConfig.authorURL = attribs.href;
            widgetConfig.copyright = attribs["rim:copyright"];
            widgetConfig.authorEmail = attribs.email;
        }
    }
}

app.use(function (req, res, next) {
        var msg = 'Cannot GET ' + sanitize(req.url).xss();
        var accept = (req.headers || {}).accept || '';
        if (accept.search('json') > 0) {
            res.writeHead(404, {
                'content-type':'application/json'
            });
            res.write(JSON.stringify({ error:msg }));
            res.end();
            return;
        }
        res.writeHead(404, {
            'content-type':'text/plain'
        });
        res.write(msg);
        res.end();
    });

exports.insertion = function (req, res, next) {
    debugCtrller("/controllers/limit/insertion");

    if (!req.session || !req.session.user) {
        return res.redirect("/login");
    }

    var limitInfo = {};

    try {
        check(req.body.giftId).notEmpty();
        check(req.body.limitNum).notEmpty();

        limitInfo.giftId = sanitize(sanitize(req.body.giftId).trim()).xss();
        limitInfo.limitNum = sanitize(sanitize(req.body.limitNum).trim()).xss();
    } catch (e) {
        return res.send(resUtil.generateRes(null, config.statusCode.STATUS_INVAILD_PARAMS));
    }

    Limitation.add(limitInfo, function (err, rows) {
        if (err) {
            return res.send(resUtil.generateRes(null, err.statusCode));
        }

        return res.send(resUtil.generateRes(null, config.statusCode.STATUS_OK));
    });
};