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Lifetimes ​

Problem ​

Implement lifetimes in a production-friendly way with @vielzeug/wireit while keeping setup and cleanup explicit.

Runnable Example ​

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

Singleton (default) ​

ts
const CacheToken = createToken<Cache>('Cache');

container.factory(CacheToken, () => new LRUCache({ max: 500 }));

const a = container.get(CacheToken);
const b = container.get(CacheToken);
console.log(a === b); // true — same instance

Transient ​

ts
const RequestIdToken = createToken<string>('RequestId');

container.factory(RequestIdToken, () => crypto.randomUUID(), { lifetime: 'transient' });

const id1 = container.get(RequestIdToken);
const id2 = container.get(RequestIdToken);
console.log(id1 === id2); // false — new UUID each time

Scoped ​

ts
const RequestContextToken = createToken<RequestContext>('RequestContext');

container.bind(RequestContextToken, RequestContext, { lifetime: 'scoped' });

const child1 = container.createChild();
const child2 = container.createChild();

console.log(child1.get(RequestContextToken) === child2.get(RequestContextToken)); // false

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.