@plinthjs/bus

Mason's command bus — the Laravel Illuminate\Bus equivalent. Dispatch command objects to handlers resolved by the command's constructor, optionally passing every command through a middleware pipeline first.

Usage

import { Bus } from '@plinthjs/bus'

class SendWelcomeEmail {
  constructor(public readonly userId: number) {}
}

const bus = new Bus()

// Register a handler for a command class (`Bus::map` in Laravel).
bus.register(SendWelcomeEmail, async (command) => {
  return `welcomed ${command.userId}`
})

const result = await bus.dispatch(new SendWelcomeEmail(7))
// => 'welcomed 7'

Mapping many handlers at once

bus.map([
  [CreateOrder, (c) => createOrder(c)],
  [CancelOrder, (c) => cancelOrder(c)],
])

Middleware (pipeThrough)

Middleware wraps the handler. Call next(command) to continue (returning the inner result), or return a value to short-circuit.

bus.pipeThrough([
  async (command, next) => {
    console.time('dispatch')
    const result = await next(command)
    console.timeEnd('dispatch')
    return result
  },
])

Self-handling commands

A command that carries its own handle() needs no registration:

class PingCommand {
  handle() {
    return 'pong'
  }
}

await bus.dispatch(new PingCommand()) // => 'pong'

Synchronous dispatch

dispatchSync returns the handler's result without awaiting — it throws if any handler or middleware actually does async work.

const value = bus.dispatchSync(new PingCommand())

Queueing (stub)

dispatchToQueue records the command onto the public queued[] array instead of running it inline; real queue integration lands later.

await bus.dispatchToQueue(new SendWelcomeEmail(7))
bus.queued // => [SendWelcomeEmail { userId: 7 }]