Typescript confusion

[ivandotv]

Library Affected:
workbox-window
Browser & Platform:
"all browsers".*

Issue or Feature Request Description:
I'm trying to use workbox-window in Typescript however, the package doesn't export any event type declarations?

wb.addEventListener('waiting', (evt: WorkboxLifecycleWaitingEvent) => {})  // error

WorkboxLifecycleWaitingEvent is not exported from workbox-window

[jeffposnick]

Hello!

While it's true that WorkboxLifecycleWaitingEvent is not explicitly exported, that's because you should never need to instantiate an instance from your own code. You're passed an instance of WorkboxLifecycleWaitingEvent via the waiting callback as the first parameter, and there's no need to explicitly state its type like you're doing in the code snippet—TypeScript knows that it's a WorkboxLifecycleWaitingEvent automatically:

I think that that's the standard way for library authors to deal with this sort of thing, and is therefore not something that we have plans to change. If I'm misunderstanding a use case, or if this breaks something for you, please let me know and we can reevaluate.

[ivandotv]

That is true, only if you create the function inline.

wb.addEventListener('waiting', handleWaiting)  // error
wb.addEventListener('waiting', myClassInstance.handleWaiting)  // error

The first case is very common.
Also , ESLint can give you an error there, depending on your configuration.

This is very limiting

[jeffposnick]

Fair enough! We can get those event definitions exported as part of an upcoming Workbox v6 release.

[jeffposnick]

The fix is now deployed in a pre-release of Workbox v6.2.0: https://github.com/GoogleChrome/workbox/releases/tag/v6.2.0-alpha.0