Function on

packages/tui/src/context/event.ts:22–30

(
    type: T,
    handler: (event: Extract<Event, { type: T }>, metadata: EventMetadata) => void,
  )

  }

  function on<T extends Event["type"]>(
    type: T,
    handler: (event: Extract<Event, { type: T }>, metadata: EventMetadata) => void,
  ) {
    return subscribe((event: Event, metadata: EventMetadata) => {
      if (event.type !== type) return
      handler(event as Extract<Event, { type: T }>, metadata)
    })
  }

  return {
    subscribe,