spongebob-handler.js

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

const spongebob = text => {
    const og = [...text.toLowerCase()];
    for (let i = 0; i < og.length; i++) {
        if (Math.random() > 0.5) og[i] = og[i].toUpperCase();
    }
    return og.join('');
};

exports.handler = function(event, context, callback) {
    // 1
    callback(null, { statusCode: 200, body: '' });
    
    // 2
    const query = querystring.parse(event.body);
    const originalMessage = query.text;
    const responseInfo = url.parse(query.response_url)

    // 3
    const delayedSpongebob = JSON.stringify({
        text: spongebob(originalMessage),
        response_type: "in_channel"
    });

    // 4
    const req = https.request({
        hostname: responseInfo.host,
        port: 443,
        path: responseInfo.path,
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
            'Content-Length': delayedSpongebob.length
        }
    });
    req.write(delayedSpongebob);
    req.end();
};