Caching and versioning#

The caching mechanism in Re.Pack prevents scripts over-fetching, which helps reducing bandwidth usage, specially since they can easily take up multiple MBs od data.

Providing storage options to ScriptManager.shared.setStorage will enable caching of downloaded script. The storage option accepts anything with similar API to AsyncStorage's getItem, setItem and removeItem functions.

By default, ScriptManager will compare the method/url/query/header or body returned by resolve with the values stored in storage to determine if downloading is necessary. Skipping the download will only happen, if the values are equal, meaning you can introduce versioning by changing the url, for example:

import { ScriptManager, Script } from '@callstack/repack/client';

ScriptManager.shared.setStorage(AsyncStorage);
ScriptManager.shared.addResolver(async (scriptId) => {
  const { version } = await getRemoteConfig();

  return {
    url: Script.getRemoteURL(`http://my-domain.dev/v${version}/${scriptId}`),
  };
});

Or by keeping the base URL inside remote config:

import { ScriptManager, Script } from '@callstack/repack/client';

ScriptManager.shared.setStorage(AsyncStorage);
ScriptManager.shared.addResolver(async (scriptId) => {
  const { baseURL } = await getRemoteConfig();

  return {
    url: Script.getRemoteURL(`${baseURL}/${scriptId}`),
  };
});

Usually cache invalidation happens automatically, but it's possible to invalidate chunk manually as well using ScriptManager.shared.invalidateScripts(...), which removes the scripts from filesystem and from the storage.