paperclip/server/src/__tests__/setup-supertest.ts

import { createRequire } from "node:module";
import type { AddressInfo, Server as NetServer } from "node:net";
import { Server as TlsServer } from "node:tls";

type SupertestServer = NetServer & {
  address(): ReturnType<NetServer["address"]>;
  listen(port: number): NetServer;
};

type SupertestTestInstance = {
  _server?: SupertestServer;
};

type SupertestTestConstructor = {
  prototype: {
    serverAddress(this: SupertestTestInstance, app: SupertestServer, path: string): string;
    __paperclipLoopbackPatched?: boolean;
  };
};

const require = createRequire(import.meta.url);
const SupertestTest = require("supertest/lib/test.js") as SupertestTestConstructor;

if (!SupertestTest.prototype.__paperclipLoopbackPatched) {
  SupertestTest.prototype.serverAddress = function serverAddress(app, path) {
    const addr = app.address();

    if (!addr) {
      this._server = app.listen(0) as SupertestServer;
    }

    const listeningAddress = app.address() as AddressInfo | string | null;
    if (!listeningAddress || typeof listeningAddress === "string") {
      throw new Error("Expected Supertest server to listen on a TCP port");
    }

    const host = listeningAddress.address === "::"
      ? "[::1]"
      : listeningAddress.address === "0.0.0.0"
        ? "127.0.0.1"
        : listeningAddress.address;
    const protocol = app instanceof TlsServer ? "https" : "http";
    return `${protocol}://${host}:${listeningAddress.port}${path}`;
  };

  SupertestTest.prototype.__paperclipLoopbackPatched = true;
}