webworker: waitUntil should require a Promise

[punkeel]

webworker lib Update Request

Missing / Incorrect Definition

Today, ExtendableEvent's waitUntil accepts any. A common mistake is to pass it a function, expecting the engine to call it. It doesn't, and will silently fail.

This is defined here:

TypeScript/lib/lib.webworker.d.ts

Line 1542 in cec2fda

waitUntil(f: any): void;

I would argue this needs to be typed as Promise<any> rather than any. This will catch two mistakes:

• Passing a function, expecting it will be called
• Passing a value, expecting it won't be called right away (eg: waitUntil(longTask());, with longTask a non-async function).

Documentation Link

https://developer.mozilla.org/en-US/docs/Web/API/ExtendableEvent/waitUntil

Parameters
A Promise.

[RyanCavanaugh]

That sounds reasonable

[jakebailey]

This was fixed in #49596.