1. cacheMaps option

This option allows to redirect a request to a cache or another request. Imagine your are developing your website with the App-Shell pattern and you cache your app-shell as index page /. Now when user visits /something-else we need to serve the same app-shell to them from the cache. It can easily be done with cacheMaps:

new OfflinePlugin({
  cacheMaps: [
    {
      match: function(requestUrl) {
        return new URL('/', location);
      },
      requestTypes: ['navigate']
    }
  ]
})

Available properties on a map object:

• match: string | RegExp | function -- matches an URL to map to a cache. If function is specified it accepts 2 arguments: URL object of a request and Request itself as the second argument. Return value of the specified function is used as the new URL. It must be a URL object.
• to: string | function -- only used if match is a not a function. Each URL is matched with urlString.replace(map.match, map.to) so to option is the second argument to String#replace function being called on the request url.
• requestTypes: Array -- An array of request types this map should be used with. Could be any combination of values: 'navigate', 'same-origin', 'cross-origin'. Example: requestTypes: ['navigate', 'same-origin']