PushManager getSubscription missing possible null return

[arjunyel]

TypeScript Version: 2.8.0-dev.20180208

Search Terms: pushManager getSubscription() TSJS

Code

ServiceWorkerRegistration.pushManager.getSubscription().then((PushSubscription) => {
console.log(PushSubscription);
});

Expected behavior:

Per the spec getSubscription returns type PushSubscription or null.

Actual behavior:
getSubscription returns type PushSubscription

[mhegazy]

PRs welcomed. You can find more information about contributing lib.d.ts fixes at https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md#contributing-libdts-fixes.

[arjunyel]

PR submitted 🎉 microsoft/TypeScript-DOM-lib-generator#367