Function withDevServer

packages/node/test/unit/dev.test.ts:43–92

(
  entrypoint: string,
  fn: (url: string) => Promise<void>,
  options: { runningTimeout?: number; runtime?: 'node' | 'bun' } = {}
)

}

async function withDevServer(
  entrypoint: string,
  fn: (url: string) => Promise<void>,
  options: { runningTimeout?: number; runtime?: 'node' | 'bun' } = {}
) {
  const { runningTimeout, runtime = 'node' } = options;
  const child = await testForkDevServer(entrypoint, runtime);

  const result = await readMessage(child);
  if (result.state !== 'message') {
    throw new Error('Exited. error: ' + JSON.stringify(result.value));
  }
  const { address = 'localhost', port } = result.value;
  const url = `http://${address}:${port}`;

  const start = Date.now();

  try {
    return await fn(url);
  } finally {
    const elapsed = Date.now() - start;
    if (runningTimeout) await setTimeout(runningTimeout - elapsed);

    // Bun uses spawn() not fork(), so no IPC. Use SIGTERM to gracefully shut down.
    if (runtime === 'bun') {
      if (child.pid) {
        try {
          process.kill(child.pid, 'SIGTERM');
        } catch (_err) {
          // Process might have already exited
        }
      }
    } else {
      child.send('shutdown', error => {
        if (error) {
          console.log('Shutdown error:', error);
          try {
            child.kill(9);
          } catch (killError) {
            // In Node 22, there's a bug where attempting to kill a child process
            // results in an EPERM error. Ignore the error in that case.
            // See: https://github.com/nodejs/node/issues/51766
            console.log('Ignoring kill error:', killError);
          }
        }
      });
    }
    if (child.exitCode === null) await once(child, 'exit');
  }
}

describe('web handlers', () => {
  describe.each(['node', 'bun'] as const)('for %s runtime', runtime => {