Hi evereyone, I'm Karam, CompSci student. This is my first post here, don't hesitate to point out anything wrong i wrote.

I'm working on TempusStack, a simple Docker orchestration tool I'm building to learn about containerization and testing workflows. I've hit a tricky race condition that I can't seem to solve.

The Problem

My Jest tests work perfectly when run sequentially (jest --runInBand) but fail randomly during parallel execution. Tests see Docker containers from other test files that should have been cleaned up.

beforeAll(async () => {
  await down(); // removes all tempusstack_* containers
});

test('CLI status prints no containers', async () => {
  const { stdout } = await execa('node', ['bin/tempusstack.js', 'status']);
  expect(stdout).toMatch(/No tempusstack container/);
});

What I've Tried

Polling after removal:

async function waitForContainersToBeGone(maxRetries = 20, delayMs = 200) {
  for (let i = 0; i < maxRetries; i++) {
    const containers = await getTempusstackContainers(docker);
    if (containers.length === 0) {
      await new Promise(resolve => setTimeout(resolve, 100));
      const doubleCheck = await getTempusstackContainers(docker);
      if (doubleCheck.length === 0) return;
    }
    await new Promise(resolve => setTimeout(resolve, delayMs));
  }
}

Other attempts:

• Shared Docker instance across all tests
• Longer wait times and forced removal
• Test-specific cleanup with unique prefixes

None of these approaches resolved the intermittent failures.

My Theory

The issue appears to be Docker's asynchronous internal cleanup:

• container.remove() completes successfully
• docker.listContainers() shows the container is gone
• Docker's internal state isn't fully consistent yet
• Parallel tests see "ghost" containers

Looking for Input

Have you encountered similar Docker timing issues with Jest? I'm particularly interested in:

• Better approaches for waiting on Docker cleanup completion
• Alternative test isolation strategies
• Docker API timing quirks I might be missing

Full details and code examples are in the GitHub issue.
Any insights would be greatly appreciated. This seems like a common enough pattern that others must have solved it before.