Add _events and cb to the callback function in EventHandler

[tetranoir]

Add _events and cb to the callback function in EventHandler to make reflection easier.

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[thdxr]

can you achieve what you need to by wrapping the EventHandler function? this does feel like a bit of a hack to put in

[tetranoir]

Yea, I did just that. This is what I have now

/**
 * @file Drop in replacements for SST's EventHandler and
 * an event bus createEventBuilder instance.
 */
import * as SST from 'sst/node/event-bus';
// Extracted SST types
import { SstEvent, SstEventCallback, SstEventHandler } from './sst-types.js';
// My custom publishEvent function
import { publishEvent } from '@local-lib/local-event-bus.js';


/**
 * Proxies SST EventHandler. Adds a `events` to the return object.
 * @param _events uses _ because that's what SST.EventHandler calls it.
 */
export const EventHandler = <E extends SstEvent>(
  _events: E[],
  cb: SstEventCallback<E>,
): ReturnType<SstEventHandler<E>> & { events: E[], cb: SstEventCallback<E> } => {
  const events = Array.isArray(_events) ? _events : [_events];

  return Object.assign(SST.EventHandler<E>(events, cb), { events, cb });
};

/**
 * Use this to define events that mean to work with SST event bus.
 */
export const createEvent: ReturnType<typeof SST.createEventBuilder> = (name, shape) => {
  const event = SST.createEventBuilder({
    bus: 'Bus', // Can't use the dynamic resource name EventBus.Bus.eventBusName.
  })(name, shape);

  // If local, monkeypatch publish to instead resolve locally.
  // TODO: BAD
  if (process.env.EVENT_BUS === 'local') {
    event.publish = async (props) => {
      publishEvent(event, props);
      // Mocks AWS PutEventsCommandOutput
      return {
        $metadata: { httpStatusCode: 200 },
        FailedEntryCount: 0,
        Entries: [],
      };
    };
  }

  // Leaving as any because the generics in createEventBuilder don't transfer well.
  return event as any;
};