Vielzeug

Appearance

Awaiting a one-time event ​

Problem ​

Implement awaiting a one-time event in a production-friendly way with @vielzeug/eventit while keeping setup and cleanup explicit.

Runnable Example ​

The snippet below is copy-paste runnable in a TypeScript project with @vielzeug/eventit installed.

Use wait() for async coordination between modules:

ts
// Module A: waits for auth before doing work
async function loadDashboard() {
  const { userId } = await appBus.wait('user:login', AbortSignal.timeout(10_000));
  const data = await fetchDashboard(userId);
  renderDashboard(data);
}

// Module B: triggers the event independently
function onAuthSuccess(user: User) {
  appBus.emit('user:login', { userId: user.id, email: user.email });
}

Expected Output ​

  • The example runs without type errors in a standard TypeScript setup.
  • The main flow produces the behavior described in the recipe title.

Common Pitfalls ​

  • Forgetting cleanup/dispose calls can leak listeners or stale state.
  • Skipping explicit typing can hide integration issues until runtime.
  • Not handling error branches makes examples harder to adapt safely.