Method addToMap

packages/vite/src/shared/hmr.ts:121–125

(map: Map<string, any[]>)

    cb: (payload: InferCustomEventPayload<T>) => void,
  ): void {
    const addToMap = (map: Map<string, any[]>) => {
      const existing = map.get(event) || []
      existing.push(cb)
      map.set(event, existing)
    }
    addToMap(this.hmrClient.customListenersMap)
    addToMap(this.newListeners)
  }