Function defineNetwork

src/core/experimental/define-network.ts:111–244

(
  options: DefineNetworkOptions<Sources>,
)

 * await network.enable()
 */
export function defineNetwork<Sources extends Array<NetworkSource<any>>>(
  options: DefineNetworkOptions<Sources>,
): NetworkApi<Sources> {
  let readyState: NetworkReadyState = NetworkReadyState.DISABLED
  const events = new Emitter<MergeEventMaps<Sources>>()
  const disposable = new Disposable()

  const deriveHandlersController = (
    handlers: DefineNetworkOptions<Sources>['handlers'],
  ) => {
    return handlers instanceof HandlersController
      ? handlers
      : new InMemoryHandlersController(handlers || [])
  }

  let resolvedOptions: DefineNetworkOptions<Sources> = {
    ...options,
  }

  /**
   * @note Create the handlers controller immediately because
   * certain setup APIs, like `setupServer`, don't await `.enable` (`.listen`).
   */
  let handlersController = deriveHandlersController(resolvedOptions.handlers)

  return {
    get readyState() {
      return readyState
    },
    events,
    configure(options) {
      invariant(
        readyState === NetworkReadyState.DISABLED,
        'Failed to call "configure()" on the network: cannot configure an already enabled network.',
      )

      if (
        options.handlers &&
        !Object.is(options.handlers, resolvedOptions.handlers)
      ) {
        handlersController = deriveHandlersController(options.handlers)
      }

      resolvedOptions = {
        ...resolvedOptions,
        ...options,
      }
    },
    enable() {
      invariant(
        readyState === NetworkReadyState.DISABLED,
        'Failed to call "enable" on the network: already enabled',
      )

      readyState = NetworkReadyState.ENABLED

      /**
       * @note Use a session object scoped to the current "enable()"