salix/back/methods/vn-user/renew-token.js

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

module.exports = Self => {
    Self.remoteMethodCtx('renewToken', {
        description: 'Checks if the token has more than renewPeriod seconds to live and if so, renews it',
        accessType: 'WRITE',
        accepts: [],
        returns: {
            type: 'Object',
            root: true
        },
        http: {
            path: `/renewToken`,
            verb: 'POST'
        }
    });

    Self.renewToken = async function(ctx) {
        const models = Self.app.models;
        const userId = ctx.req.accessToken.userId;
        const created = ctx.req.accessToken.created;
        const tokenId = ctx.req.accessToken.id;

        const now = new Date();
        const differenceMilliseconds = now - new Date(created);
        const differenceSeconds = Math.floor(differenceMilliseconds / 1000);

        const accessTokenConfig = await models.AccessTokenConfig.findOne({fields: ['renewPeriod']});

        if (differenceSeconds <= accessTokenConfig.renewPeriod)
            throw new UserError(`The renew period has not been exceeded`);

        await Self.logout(tokenId);
        const user = await Self.findById(userId);
        const accessToken = await user.createAccessToken();

        return {token: accessToken.id, created: accessToken.created};
    };
};