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