Using Node.js to connect to a REST API

Question

Is it sensible to use Node.js to write a stand alone app that will connect two REST API\'s?

One end will be a POS - Point of sale - system

The other will be

Answer 1

/*Below logics covered in below sample GET API    
    -DB connection created in class
    -common function to execute the query 
    -logging through bunyan library*/


const { APIResponse} = require('./../commonFun/utils');
    const createlog = require('./../lib/createlog');
    var obj = new DB();
    //Test API
    routes.get('/testapi', (req, res) => {
        res.status(201).json({ message: 'API microservices test' });
    });
    dbObj = new DB();
    routes.get('/getStore', (req, res) => {
        try {
            //create DB instance

            const store_id = req.body.storeID;
            const promiseReturnwithResult = selectQueryData('tablename', whereField, dbObj.conn);
            (promiseReturnwithResult).then((result) => {
                APIResponse(200, 'Data fetched successfully', result).then((result) => {
                    res.send(result);
                });
            }).catch((err) => { console.log(err); throw err; })
        } catch (err) {
            console.log('Exception caught in getuser API', err);
            const e = new Error();
            if (err.errors && err.errors.length > 0) {
                e.Error = 'Exception caught in getuser API';
                e.message = err.errors[0].message;
                e.code = 500;
                res.status(404).send(APIResponse(e.code, e.message, e.Error));
                createlog.writeErrorInLog(err);
            }
        }
    });

    //create connection
    "use strict"
    const mysql = require("mysql");

    class DB {
      constructor() {
        this.conn = mysql.createConnection({
          host: 'localhost',
          user: 'root',
          password: 'pass',
          database: 'db_name'
        });
      }

      connect() {
        this.conn.connect(function (err) {
          if (err) {
            console.error("error connecting: " + err.stack);
            return;
          }
          console.log("connected to DBB");
        });
      }
      //End class
    }

    module.exports = DB


    //queryTransaction.js File

    selectQueryData= (table,where,db_conn)=>{  
        return new Promise(function(resolve,reject){
          try{  
              db_conn.query(`SELECT * FROM ${table} WHERE id = ${where}`,function(err,result){
                if(err){
                  reject(err);
                }else{
                  resolve(result);
                }
            });
          }catch(err){
              console.log(err);
          }
        });
    }

    module.exports= {selectQueryData};

    //utils.js file

    APIResponse = async (status, msg, data = '',error=null) => {  
      try {
        if (status) {
          return { statusCode: status, message: msg, PayLoad: data,error:error }
        }
      } catch (err) {
        console.log('Exception caught in getuser API', err);
      }
    }

    module.exports={
      logsSetting: {
        name: "USER-API",
        streams: [
            {
                level: 'error',
                path: '' // log ERROR and above to a file
            }
        ],
      },APIResponse
    }

    //createlogs.js File

    var bunyan = require('bunyan');
    const dateFormat = require('dateformat');
    const {logsSetting} = require('./../commonFun/utils');

    module.exports.writeErrorInLog = (customError) => {
      let logConfig = {...logsSetting};
      console.log('reached in writeErrorInLog',customError)
      const currentDate = dateFormat(new Date(), 'yyyy-mm-dd');
      const path = logConfig.streams[0].path = `${__dirname}/../log/${currentDate}error.log`;
      const log = bunyan.createLogger(logConfig);
      log.error(customError);

    }