08. Resource Scopes & Async Resolvers

Manage deterministic lifecycle teardowns upon block-scope exit and decouple promise resolutions from constructor callbacks.

resource-scopes.ts

// 1. Explicit Resource Management (ERM) with using keyword
class DatabaseConnection implements Disposable {
  constructor(public id: string) {}
  [Symbol.dispose]() {
    console.log(`Released DB handle: ${this.id}`);
  }
}

function processTransaction() {
  using conn = new DatabaseConnection('neon-pool-1');
  // Auto-disposed upon exiting scope, even on throw
}

// 2. Promise.withResolvers() Decoupling
const { promise, resolve, reject } = Promise.withResolvers<string>();
setTimeout(() => resolve('Deferred Pipeline Ready'), 500);

Key Mechanics

using (Symbol.dispose): Scoped deterministic teardown for sockets, DB handles, and locks.
Promise.withResolvers(): Direct access to resolve and reject callbacks without promise constructor closures.

Scoped Resource Allocator Idle

No active resource scopes initialized.

Promise.withResolvers Controller Status: idle

Buffer:

Idle

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