Explicit resource management for AsyncLocalStorage

[everett1992]

What is the problem this feature will solve?

Does it make sense to add a method to AsyncLocalStorage that returns Disposable?

What is the feature you are proposing to solve the problem?

This is the example from AsyncLocalStorage using .run, which introduces a callback and a level of nesting that comes with that.

http.createServer((req, res) => {
 asyncLocalStorage.run(idSeq++, () => {
 logWithId('start');
 // Imagine any chain of async operations here
 setImmediate(() => {
 logWithId('finish');
 res.end();
 });
 });
})

With with explicit resource management this could be:

http.createServer((req, res) => {
 using _id = asyncLocalStorage._PROPOSED(idSeq++)

 logWithId('start');
 // Imagine any chain of async operations here
 setImmediate(() => {
 logWithId('finish');
 res.end();
 });
})

enterWith currently returns undefined, could that be updated to return a Disposable?

What alternatives have you considered?

This could be built in user-land, I think

function enterWith<T>(als: AsyncLocalStorage<T>, store: T) {
 const oldStore = als.getStore()
 console.debug(als.enterWith(store))
 const dispose = new DisposableStack()
 dispose.defer(() => als.enterWith(oldStore))
 return dispose
}

[jasnell]

Already in progress: #58104 @bengl

[everett1992]

Nice - I searched but I guess not in PRs