Lifecycle

The executor lifecycle covers the full path from registration to the moment the caller receives a result.

1. Registration (one‑time)

Before an executor can be used, its logic must be registered.
This happens once, typically during application bootstrap.

import {ConnectExecutor, PostboyExecutor} from '@artstesh/postboy';

export class FormatDateExecutor extends PostboyExecutor<string> {
  static readonly ID = 'date.format';

  constructor(public readonly date: Date) {
    super();
  }
}

postboy.exec(new ConnectExecutor(FormatDateExecutor, (executor) => {
  return Intl.DateTimeFormat('en-US').format(executor.date);
}));

From this point, the bus knows how to handle FormatDateExecutor.

2. Execution call

Any code that needs the operation passes an executor instance to postboy.exec(…).

const result = postboy.exec(new FormatDateExecutor(new Date()));

3. Middleware hooks

Before and after the handler runs, middleware can inspect, block, or augment the execution.

beforeExecute(executor) — can throw to cancel execution.
afterExecute(executor, result) — can log, measure, or modify the result.

Middleware does not replace the handler; it only observes the lifecycle.

4. Handler execution

Postboy resolves the registered logic (function or handler class) and passes the executor instance to it.

// Internally, the bus effectively calls:
// registeredFunction(executor)
// or handler.handle(executor)

The handler performs the actual work and returns the typed result.

5. Result returned

The result is passed back to the caller synchronously.

const formatted = postboy.exec(new FormatDateExecutor(new Date()));
console.log(formatted); // "4/23/2026"

Full lifecycle in sequence

Registration (executor + logic)
↓
bus.exec(executor)
↓
middleware.beforeExecute(executor)
↓
handler(executor) → result
↓
middleware.afterExecute(executor, result)
↓
return result to caller

Key points

Registration is separate from execution.
The lifecycle is synchronous from the caller’s point of view.
Middleware is the only place where cross‑cutting concerns (logging, validation) belong.
The handler remains a pure unit of work, testable in isolation.

24 апреля 2026