`enabledHooksExist()` doesn't work as intended

[gurgunday]

I took a look at enabledHooksExist(), but as discussed in #59873 (comment) and #60913, it seems to not work as intended at the moment:

Following the suggestion to use enabledHooksExist(), I spent quite some time on it and gave that a try—but found that it consistently returned true, even when no async hooks were active. So, I reverted to using getHookArrays()[0].length > 0, as it provides a more accurate reflection of the current hook state.

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enabledHooksExist() checks async_hook_fields[kCheck] > 0, but kCheck is intentionally set to 1 at Node.js startup, even when no user async hooks have been registered:

From env.cc (L1763):

node/src/env.cc

Lines 1748 to 1763 in e28656a

	AsyncHooks::AsyncHooks(Isolate* isolate, const SerializeInfo* info)
	: async_ids_stack_(isolate, 16 * 2, MAYBE_FIELD_PTR(info, async_ids_stack)),
	fields_(isolate, kFieldsCount, MAYBE_FIELD_PTR(info, fields)),
	async_id_fields_(
	isolate, kUidFieldsCount, MAYBE_FIELD_PTR(info, async_id_fields)),
	info_(info) {
	HandleScope handle_scope(isolate);
	if (info == nullptr) {
	clear_async_id_stack();
	// Always perform async_hooks checks, not just when async_hooks is enabled.
	// TODO(AndreasMadsen): Consider removing this for LTS releases.
	// See discussion in https://github.com/nodejs/node/pull/15454
	// When removing this, do it by reverting the commit. Otherwise the test
	// and flag changes won't be included.
	fields_[kCheck] = 1;

This means enabledHooksExist() always returns true, regardless of whether any AsyncHook instances have actually been created and enabled by user code.

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This behavior dates back to PR #15454 it seems, but even after going through that discussion, I don't really understand the reasoning behind it and the TODO that says we should revert this for LTS releases. I feel like fields_[kCheck] should instead be set to 0 during initialization.

Should we just change that or add a new helper function that would essentially do AsyncContextFrame.current() != null || getHookArrays()[0].length > 0?

[Flarna]

created #61054