ShutdownSignal.ts

/** Create a wrapped AbortController that is aborted when a SIGINT/SIGTERM is received.
 * Supports auto-unregistering via explicit resource management.
 *
 * @example
 * using shutdownSignal = new ShutdownSignal()
 * shutdownSignal.throwIfAborted()
 *
 * // or
 * const shutdownSignal = new ShutdownSignal()
 * try { shutdownSignal.throwIfAborted() } finally { shutdownSignal.unregister() }
 * */
export class ShutdownSignal {
  ac: AbortController
  sigintCb: () => unknown
  constructor() {
    this.ac = new AbortController()

    this.sigintCb = () => {
      this.ac.abort()
      this.unregister()
    }

    process.on('SIGINT', this.sigintCb)
    process.on('SIGTERM', this.sigintCb)
  }
  get isShuttingDown() {
    return this.ac.signal.aborted
  }
  unregister() {
    process.off('SIGINT', this.sigintCb)
    process.off('SIGTERM', this.sigintCb)
  }
  throwIfShuttingDown() {
    if (this.isShuttingDown) {
      throw new Error('SHUTTING_DOWN')
    }
  }
  [Symbol.dispose]() {
    this.unregister()
  }
}