upload.js

exports.upload = function(req, res){

  var form = new formidable.IncomingForm();

  form.parse(req, function(err, fields, files) {

      readFile(files.file.path)
        .then(processRows)
        .then(processProducts)
        .then(function(arrData){
            res.send({resposta: arrData});
        })
  })

};

function readFile(path) {

    return new Promise(function(resolve, reject){

        fs.readFile(path, function(err, data){
            if(err)
              return reject(err);

            resolve(data);
        })

    })
}

function processRows(data){

    return new Promise(function(resolve, reject){

        var rows = encoding.convert(data.toString().split('\r\n'), 'utf8');
        var arrData = []

        rows.forEach(function(row){

          var arr = [];
          arr.push(row.split(';'));

          if( !isNaN(parseFloat(arr[0][0])) && isFinite(arr[0][0]) ){

             arrData.push({"code": arr[0][0], "product": 'Não cadastrado', "factory": arr[0][1], "price": arr[0][2]})

          }

        })

        resolve(arrData)

    })

}

function processProducts(arrData){

    const codes = arrData.map(code => code)
    const promises = codes.map(processProduct)

    return Promise.all(promises)

}

function processProduct(code){

    return new Promise(function(resolve, reject){

        model.Produto.findAll({
          where: {
            cod_produto: code.code
          }
        }).then(function(products){

              code.product = products[0] ? products[0].desc_produto : 'Não cadastrado'
              resolve(code)
        })

    })
}