src/sw.js

import { registerRoute } from 'workbox-routing'
import { StaleWhileRevalidate } from 'workbox-strategies'

export default function swCustom(params) {
    if (params.debug) {
        console.log('[WebdriverIO-PWA][SW]: running swCustom code', params)
    }

    // Cache responses from external resources
    registerRoute((context) => {
        return [
            /graph\.facebook\.com\/.*\/picture/,
            /netlify\.com\/img/,
            /avatars1\.githubusercontent/,
        ].some((regex) => context.url.href.match(regex))
    }, new StaleWhileRevalidate())
}