image-diff.js

await page.goto('https://www.wikihow.com/Tie-Your-Shoes');
await page.waitForSelector('#article_shell');
await page.screenshot({
    path: './production.png',
    fullPage: false,
})
await page.goto('https://www.wikihow.com/Tie-Your-Shoes');
await page.waitForSelector('#article_shell');
await page.screenshot({
    path: './local.png',
    fullPage: false,
})

let img1 = fs.createReadStream('./production.png')
.pipe(new PNG()).on('parsed', doneReading)
.on('error', function () { reject() });

let img2 = fs.createReadStream('./local.png')
.pipe(new PNG()).on('parsed', doneReading)
.on('error', function () { reject() });

let filesRead = 0
function doneReading() {
    if (++filesRead < 2) return;
    var diff = new PNG({ width: img1.width, height: img1.height });

    pixelmatch(img1.data, img2.data, diff.data, img1.width, img1.height, { threshold: 0.1 });

    diff.pack().pipe(fs.createWriteStream('diff.png'));
    resolve()
}