Workbox v4.0.0-rc.3

The latest RC release of Workbox v4 includes the following developer-visible changes, in addition to all the changes from the previous pre-releases.

🎉 What's New?

workbox-window

• Lifecycle events dispatched by the Workbox class now include an isUpdate property. This property can be used to distinguish lifecycle events in the follow scenarios: 1) the very first service worker installation (isUpdate === undefined), 2) an update from a previous service worker version (isUpdate === true).

• The waiting event dispatched by the Workbox class will now include a wasWaitingBeforeRegistration flag in the event that there was already a service worker waiting when the current service worker was registered. When this is true, it typically means there are other open tabs preventing the service worker from activating (or the user is reloading the current tab). See The Service Worker Lifecycle: skip the waiting phase for more details on why this can happen. [#1905]

🐛 What's Fixed?

workbox-routing

• The message event listener added via addCacheListener() now no longer requires event.data.metadata to equal workbox-window. This allows developers not using workbox-window to still be able to send cache messages to their service worker. [#1906]