zone + async

original.ts

async function myCode() {
  const value = await doSomething();
  const value2 = await somethingElse(value)
  return value2 + 1;
}

rewrite.ts

async function myCode() {
  const restoreZone = saveCurrentZone();
  try {
    const value = restoreZone(await doSomething());
    const value2 = restoreZone(await somethingElse(value));
    return value2 + 1;
  } finally {
    restoreZone(closeToken);
  }
}

supporting

// global support
function saveCurrentZone() { ... }

const closeToken = {}; // globally unique object to use as a token