import express from 'express';
import conn from '../models/connection';
const c =  conn;

class ClientRoutes {
...
    getMainPage(req, res, next) {
        c.openConection().then((a) => {
            console.log(a);
            res.render('index', {title: 'Abner'})
        })
    }
...

import r from 'rethinkdb';

class Db_Conection {

    openConection(req, res, next) {
        return new Promise((resolve) => {
            r.connect({host: process.env.DB_HOST, port: process.env.DB_PORT}, (err, conn) => {
                if ( err && err.name === 'ReqlDriverError' && err.message.indexOf( 'Could not connect' ) === 0 && ++count < 3 ) {
                    console.log( err );
                    return;
                }
                resolve(conn);
            })
        })
    }
...

...
    async openConection(req, res, next) {
        r.connect({host: process.env.DB_HOST, port: process.env.DB_PORT}, (err, conn) => {
            if ( err && err.name === 'ReqlDriverError' && err.message.indexOf( 'Could not connect' ) === 0 && ++count < 3 ) {
                console.log( err );
                return;
            }
            return conn;
        })
    }
...

...
    async getMainPage(req, res, next) {
        const b = await c.openConection();
        console.log(b);
        // res.render('index', {title: 'Abner'})
    }
...

openConection(req, res, next) {
    return new Promise((resolve) => {
        r.connect({host: process.env.DB_HOST, port: process.env.DB_PORT}, (err, conn) => {
            if ( err && err.name === 'ReqlDriverError' && err.message.indexOf( 'Could not connect' ) === 0 && ++count < 3 ) {
                console.log( err );
                return;
            }
            resolve(conn);
        })
    })
}

async getMainPage(req, res, next) {
    try {
        const b = await c.openConnection();
        console.log(b);
        res.render('index', {title: 'Abner'})
    } catch (error) {
        // Caso a promise seja rejeitada, trata o erro
        res.status(500).json({mgs: "Um erro ocorreu"})
}