runInBand + dynamic imports break in Jest 27.0.0-next.11

[jakobrosenberg]

🐛 Bug Report

Running jest in parallel works fine, but with runInBand enabled, all tests with dynamic imports fail with the error Test environment has been torn down

Often, if I run a single test, the test will work the first time and then error on subsequent tests. Changing the imported file will fix the test on the next run, but then fail on the subsequent ones.

To reproduce

//foo.js
export default 'hello'

//faulty.test.js
test('test1', async () => {
    const module = await import('./foo.js')
    expect(module).toBeDefined()
})

Run the above test with --runInBand --watch. Once finished, click enter to trigger another run.

Expected behavior

Test should pass on subsequent runs, but instead only the first test passes and subsequent runs break.

envinfo

Verified on:
Windows, Mac, Ubuntu (Github action), WSL
Node: 14 & 15
NPM: 6 & 7

  System:
    OS: Windows 10 10.0.19041
    CPU: (16) x64 AMD Ryzen 7 1700 Eight-Core Processor
  Binaries:
    Node: 14.17.0 - ~\AppData\Local\Volta\tools\image\node\14.17.0\node.EXE
    Yarn: 1.21.1 - C:\Program Files\Volta\yarn.EXE
    npm: 6.14.13 - ~\AppData\Local\Volta\tools\image\npm\6.14.13\bin\npm.CMD
  npmPackages:
    jest: ^27.0.0-next.11 => 27.0.0-next.11

[ahnpnl]

I tried this code on my Mac

test('should work', async () => {
  const packageJson = await import('../../package.json');

  expect(packageJson).toBeDefined();
});

but i don't see the issue. How do you run into it?

[jakobrosenberg]

After some further debugging this seems to be what causes the flaky behavior:

const module = await import(path).then(r => r.default)

Omitting either the await or the then fixes the issue.

EDIT: I may have been too hasty in this conclusion. Doing some further testing.

[jakobrosenberg]

@ahnpnl could you try this snippet in watch mode. If it doesn't fail on first test, try hit enter to trigger another test.

test('test1', async () => {
    const res= await import('some/file.js') //not package.json, but a .js file
    expect(res).toBeTruthy()
})

[ahnpnl]

hmm i still don't see the issue, what if you clear Jest cache and try again?

[SimenB]

Could you put together a minimal repository showing the error?

[fwh1990]

https://github.com/easy-demo/ts-jest-issue/tree/await-import
Look at this branch.

[fwh1990]

It's not about async/await, it will fail to test once we use import() syntax with jest --runInBand

[fwh1990]

This picture shows there are two files executed, index2.test.ts succeed and another failed. However, they are just the same file except filename.

[azban]

seems related to #10944

i'm running into the same issue with ESM and --runInBand and think i'm running into a similar issue as seen in #10944 (comment)

Same issue here, is there some work around that you have used?
What i get here is that in jest-runtime index.js line 532,
const context = this._environment.getVmContext();
this function is returning null, for second test file.

[damianobarbati]

@azban is there a workaround for this? I have it either with --runInBand or without.

[azban]

i haven't found a workaround, but also am not seeing this issue with --runInBand, so you may be seeing something else.