Nodejs Serverless code for https://github.com/RealDyllon/react-supermarket-tracker

sheng-shiong-delivery.js

const https = require('https');
const querystring = require('querystring');

exports.handler = async(event) => {
    let dataString = '';

    const httpOrigin = event.headers.origin

    const allowedOrigins = [
        "https://supermarkets.dyllon.dev"
    ]

    const isAllowed = allowedOrigins.indexOf(httpOrigin) > -1

    // grab our params from the lambda proxy integration
    const reqParamsData = {
        code: (event &&
                event.queryStringParameters) ?
            event.queryStringParameters.postcode : "000000",
        pinStatus: 1
    }

    // console.log("postcode", reqParamsData.code)

    const reqParams = querystring.stringify(reqParamsData);

    // const reqParams = JSON.stringify(reqParamsData);

    // https://www.allforyou.sg/Common/pinCodeSearch
    const reqOptions = {
        method: 'POST',
        hostname: 'www.allforyou.sg',
        path: '/Common/pinCodeSearch',
        headers: {

            "Host": "allforyou.sg",
            "User-Agent": "Mozilla/5.0 (Windows; U; MSIE 9.0; Windows NT 9.0; en-US);",
            "Accept": "application/json, text/javascript, */*; q=0.01",
            "Accept-Language": "en-US,en;q=0.5",
            "Accept-Encoding": "gzip, deflate, br",
            "Content-Type": "application/x-www-form-urlencoded",
            "X-Requested-With": "XMLHttpRequest",
            "Content-Length": reqParams.length,
            "Origin": "https://allforyou.sg",
            "Connection": "keep-alive",
            "Referer": "https://allforyou.sg/",

        }
    }

    const response = await new Promise((resolve, reject) => {

        // define the https request
        const req = https.request(reqOptions, res => {

            //append to data string in real time
            res.on('data', chunk => {
                // console.log("chunk", chunk)
                dataString += chunk;
            });

            //when we've got all the data:
            res.on('end', () => {

                console.log("dataString", (dataString))

                let dataObj = JSON.parse(dataString)

                let outputString = JSON.stringify({ ...dataObj,
                    apiParamsEcho: {
                        postcode: reqParamsData.code === "000000" ?
                            "missing!!!" : reqParamsData.code
                    }
                })

                resolve({
                    statusCode: 200,
                    headers: {
                        "Access-Control-Allow-Origin":
                            isAllowed ?
                            httpOrigin : "https://supermarkets.dyllon.dev",
                        "Access-Control-Allow-Headers": "Content-Type",
                        "Access-Control-Allow-Methods": "OPTIONS,POST,GET"
                    },
                    body: outputString
                });
            });
        })

        // abort in case of error
        req.on('error', (e) => {
            reject({
                statusCode: 500,
                headers: {
                    "Access-Control-Allow-Origin": isAllowed ?
                        httpOrigin : "https://supermarkets.dyllon.dev",
                    "Access-Control-Allow-Headers": "Content-Type",
                    "Access-Control-Allow-Methods": "OPTIONS,POST,GET"
                },
                body: 'Something went wrong!'
            });
        });

        req.write(reqParams)
        req.end()

    });

    return response;
};