Parse https://warhammerunderworlds.com for saving all cards from this game.

parserWHUW.js

const https = require("https");
const axios = require("axios");
const fs = require("fs");
const os = require("os");
const cluster = require("cluster");

const STEP = 20;

const saveFailedImg = url => {
    failedImg.push(url);
};

const downloadImage = (url, name) => {
    const filePath = `${__dirname}/images/${name}.png`;
    const file = fs.createWriteStream(filePath);
    return new Promise(resolve => {
        https.get(url, response => {
            if (response.statusCode === 200) {
                response.pipe(file).on("finish", () => {
                    console.log("File downloaded: ", filePath);
                    resolve();
                });
            } else {
                saveFailedImg(filePath);
                resolve();
            }
        });
    });
};

const failedImg = [];

const url = `https://warhammerunderworlds.com/wp-json/wp/v2/cards/?ver=13&per_page=1000`;

(async () => {
    if (cluster.isMaster) {
        cluster.on("message", (worker, msg) => console.log(msg));
        let livingChilds = 0;
        const queue = await axios
            .get(url)
            .then(res =>
                res.data.map(card => ({
                    id: card.acf.card_number,
                    url: encodeURI(card.acf.card_image.url),
                    name: card.slug
                }))
            )
            .then(images => images.sort((prev, next) => prev.id - next.id))
            .catch(e => console.log(e));
        const interval = setInterval(() => {
            if (queue.length && livingChilds <= 10) {
                livingChilds++;
                const value = queue.pop();
                cluster.fork({ value: JSON.stringify(value) }).on("disconnect", () => {
                    livingChilds--;
                });
            }

            if (!queue.length) {
                clearInterval(interval);
            }
        }, 10);
    } else {
        const value = JSON.parse(process.env.value);
        downloadImage(value.url, value.name)
            .then(res => process.exit(0))
            .catch(err => {
                console.log(err);
                exit(1);
            });
    }
})();