waitUntil/respondWith can be called inside a microtask during event dispatch.

Category: Service Worker
Type: New or changed feature
Status: Enabled by default (Chrome 75)
Intent stage: None

Summary

To conform to the specification, ExtendableEvent.waitUntil() and FetchEvent.respondWith() can now be called during the microtask checkpoint at the end of event dispatch. Previously, this would throw an InvalidStateError.

Standards & signals

Specification: https://w3c.github.io/ServiceWorker
Firefox: Positive
Safari: Shipped/Shipping
Web developers: No signals

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