Solution for exercise 7.3 A tamper-free queue

exercise_7_3.js

import http from "http";
/*------------------------------------------------------------------------------------------------------------*/
class Queue {
    constructor(executor) {
        const queue = [];
        let resolverFunctions = [];

        async function enqueue(element) {
            if(resolverFunctions.length) {
                const resolve = resolverFunctions.shift();
                resolve(element);
            } else {
                queue.push(element);    
            }
            return queue.length;
        }

        Queue.prototype.dequeue = async function() {
            if(!queue.length) {
                console.log("Queue is empty. Waiting for new element.")
                return new Promise( (resolve) => {
                    resolverFunctions.push(resolve);
                });
            }
            return Promise.resolve(queue.shift());
        }
        executor({enqueue});
    }
}
/*------------------------------------------------------------------------------------------------------------*/
const queue = new Queue( ({ enqueue }) => {
    const server = http.createServer( (request, response) => {
        let body = "";

        request.setEncoding("utf-8");
        request.on("data", (chunk) => {
            body += chunk;
        });

        request.on("end", () => {
            const words = body.split(" ").map( word => word.toUpperCase());
            for(const word of words) {
                enqueue(word);
            }
            body = "";

            response.writeHead(200, { "Content-Type" : "text/plain" })
            response.end("OK");
        })
    });

    server.listen(8080, () => {
        console.log("Server started on port %i", 8080);
    });
});
/*------------------------------------------------------------------------------------------------------------*/
async function printWordsAsync(queue) {
    while(1) {
        const word = await queue.dequeue();
        console.log("Uppercase word: %s", word);
    }
}

// Kickoff function
printWordsAsync(queue);
/*------------------------------------------------------------------------------------------------------------*/