Function createDummyServers

test/e2e/api.test.js:396–436

(n)

    });

    function createDummyServers(n) {
      const basePort = process.env.WEBPACK_DEV_SERVER_TEST_BASE_PORT || 30000;
      process.env.WEBPACK_DEV_SERVER_BASE_PORT = basePort;

      return (Array.isArray(n) ? n : Array.from({ length: n })).reduce(
        (p, _, i) =>
          p.then(
            () =>
              new Promise((resolve) => {
                devServerPort = basePort + i;
                const compiler = webpack(config);
                const server = new Server(
                  { port: devServerPort, host: "0.0.0.0" },
                  compiler,
                );

                dummyServers.push(server);

                server.startCallback((err) => {
                  if (err) {
                    // If we get EACCES, try again with a higher port range
                    if (
                      err.code === "EACCES" &&
                      !process.env.WEBPACK_DEV_SERVER_TEST_RETRY
                    ) {
                      process.env.WEBPACK_DEV_SERVER_TEST_RETRY = true;
                      process.env.WEBPACK_DEV_SERVER_TEST_BASE_PORT = 40000;
                      // Resolve and let the test restart with the new port range
                      resolve();
                    } else {
                      Promise.reject(err);
                    }
                  } else {
                    resolve();
                  }
                });
              }),
          ),
        Promise.resolve(),
      );
    }

    it("should return the port when the port is specified", async () => {
      const retryCount = 1;