export function onRequest()

in src/v2/providers/https.ts [89:194]
96 lines of code
3 McCabe index (conditional complexity)

export function onRequest(
  opts: HttpsOptions,
  handler: (
    request: Request,
    response: express.Response
  ) => void | Promise<void>
): HttpsFunction;
export function onRequest(
  handler: (
    request: Request,
    response: express.Response
  ) => void | Promise<void>
): HttpsFunction;
export function onRequest(
  optsOrHandler:
    | HttpsOptions
    | ((request: Request, response: express.Response) => void | Promise<void>),
  handler?: (
    request: Request,
    response: express.Response
  ) => void | Promise<void>
): HttpsFunction {
  let opts: HttpsOptions;
  if (arguments.length === 1) {
    opts = {};
    handler = optsOrHandler as (
      request: Request,
      response: express.Response
    ) => void | Promise<void>;
  } else {
    opts = optsOrHandler as HttpsOptions;
  }

  if ('cors' in opts) {
    const userProvidedHandler = handler;
    handler = (req: Request, res: express.Response): void | Promise<void> => {
      return new Promise((resolve) => {
        res.on('finish', resolve);
        cors({ origin: opts.cors })(req, res, () => {
          resolve(userProvidedHandler(req, res));
        });
      });
    };
  }

  Object.defineProperty(handler, '__trigger', {
    get: () => {
      const baseOpts = options.optionsToTriggerAnnotations(
        options.getGlobalOptions()
      );
      // global options calls region a scalar and https allows it to be an array,
      // but optionsToTriggerAnnotations handles both cases.
      const specificOpts = options.optionsToTriggerAnnotations(
        opts as options.GlobalOptions
      );
      const trigger: any = {
        // TODO(inlined): Remove "apiVersion" once the latest version of the CLI
        // has migrated to "platform".
        apiVersion: 2,
        platform: 'gcfv2',
        ...baseOpts,
        ...specificOpts,
        labels: {
          ...baseOpts?.labels,
          ...specificOpts?.labels,
        },
        httpsTrigger: {
          allowInsecure: false,
        },
      };
      convertIfPresent(
        trigger.httpsTrigger,
        opts,
        'invoker',
        'invoker',
        convertInvoker
      );
      return trigger;
    },
  });

  const baseOpts = options.optionsToEndpoint(options.getGlobalOptions());
  // global options calls region a scalar and https allows it to be an array,
  // but optionsToTriggerAnnotations handles both cases.
  const specificOpts = options.optionsToEndpoint(opts as options.GlobalOptions);
  const endpoint: Partial<ManifestEndpoint> = {
    platform: 'gcfv2',
    ...baseOpts,
    ...specificOpts,
    labels: {
      ...baseOpts?.labels,
      ...specificOpts?.labels,
    },
    httpsTrigger: {},
  };
  convertIfPresent(
    endpoint.httpsTrigger,
    opts,
    'invoker',
    'invoker',
    convertInvoker
  );
  (handler as HttpsFunction).__endpoint = endpoint;

  return handler as HttpsFunction;
}