Generate Signed Web Apps config file

Custom configuration

Varying configuration

As you may have noticed, all configuration options on the right are functions. This means that you can have different configurations for different resources on your website. Most of them take

(request,
response)

parameters, but shouldCheckGit only takes a request parameter. For example, to vary which branch on GitHub to look on, you could write something like:

    self.gitBranch = req => req.url.startsWith("https://www.example.com") ? "release" : "development";

Importing other Service Worker files

serviceworker-import.js is not only the file where you can configure Signed Web Apps. It is also the place to import other Service Worker files (related or unrelated to Signed Web Apps), by calling:

    await importScriptsFromSW("path/to/other/service-worker.js");

The await means that all code after it will wait until the Service Worker file is downloaded and run. If you don't need that, you can remove it. You can also download and run multiple files simultaneously, and wait until all of them have finished running, by calling:

    await importScriptsFromSW("first/service-worker.js", "second/service-worker.js");

Note: there are some differences between code you can run in a normal Service Worker, and code you can run in this file (and files imported by it), namely:

You can only register for fetch, message, install and activate events. If you want to register for other events, you have to manually add them to the eventNames list in signed-web-apps/dist/sw/serviceworker.js.
As shown in the examples above, you should use importScriptsFromSW() instead of importScripts(), because the latter doesn't support Subresource Integrity. This is also why generated config code above is wrapped in an asynchronous immediately-executed function expression.