async_hooks: If first hook is disabled, async ID tracking is permanently disabled

[kjin]

• Version: v12.0.0
• Platform: macOS 10.14.3 (likely irrelevant)
• Subsystem: async_hooks

If I create an async hook and then disable it, then async ID tracking no longer works, even if subsequent async hooks are created and enabled, or if the first async hook is re-enabled.

Repro:

const ah = require('async_hooks');
// switch the order of these two lines, and things appear to work correctly
ah.createHook({ init: () => {} }).enable().disable().enable();
ah.createHook({ init: () => {} }).enable();

async function main() {
  console.log(ah.executionAsyncId()); // should print 1
  await 0;
  console.log(ah.executionAsyncId()); // should print 7, but prints 1
}

main();

This appears to affect all of v12+ so far.

[addaleax]

Sorry, this happened because of my 96c3224 – it just happened to work out before, but the issue here is that disabling the promise hook happens asynchronously, i.e. after all the synchronous enable() calls.

#27585 should address this. :)

[kjin]

@addaleax Thanks for the fast fix! I checkout out your change and it does seem to fix the underlying issue for the module in which I encountered this problem.