Jest detects open ThreadSafeCallback handles preventing clean exit

[mertushka]

I was able to reproduce this issue by running the test few times (seems like race condition) on Windows with Node.js v22.18.0.

"test": "set NODE_OPTIONS=--experimental-vm-modules && jest --runInBand --detectOpenHandles --forceExit"

Jest reports 4 open ThreadSafeCallback handles and warns that they may be keeping Jest from exiting (p2p.test.ts):

●  ThreadSafeCallback callback

      66 |       });
      67 |
    > 68 |       dc1 = peer1.createDataChannel('test-p2p');
         |                   ^
      69 |       dc1.onOpen(() => {
      70 |         p1DCMock();
      71 |         dc1.sendMessage('Hello From Peer1');

      at test/jest-tests/p2p.test.ts:68:19
      at Object.<anonymous> (test/jest-tests/p2p.test.ts:11:12)


  ●  ThreadSafeCallback callback

      67 |
      68 |       dc1 = peer1.createDataChannel('test-p2p');
    > 69 |       dc1.onOpen(() => {
         |           ^
      70 |         p1DCMock();
      71 |         dc1.sendMessage('Hello From Peer1');
      72 |       });

      at test/jest-tests/p2p.test.ts:69:11
      at Object.<anonymous> (test/jest-tests/p2p.test.ts:11:12)


  ●  ThreadSafeCallback callback

      71 |         dc1.sendMessage('Hello From Peer1');
      72 |       });
    > 73 |       dc1.onMessage((msg) => {
         |           ^
      74 |         p1DCMessageMock(msg);
      75 |         peer1.close();
      76 |         peer2.close();

      at test/jest-tests/p2p.test.ts:73:11
      at Object.<anonymous> (test/jest-tests/p2p.test.ts:11:12)


  ●  ThreadSafeCallback callback

      57 |         peer1.addRemoteCandidate(candidate, mid);
      58 |       });
    > 59 |       peer2.onDataChannel((dc) => {
         |             ^
      60 |         p2DCMock();
      61 |         dc2 = dc;
      62 |         dc2.onMessage((msg) => {

      at test/jest-tests/p2p.test.ts:59:13
      at Object.<anonymous> (test/jest-tests/p2p.test.ts:11:12)

[achingbrain]

I've noticed something similar, when the RTCPeerConnection polyfill's connectionState changes to closed, .close() isn't called on the internal C++ PeerConnection object which means it stays alive in memory.