Semaphore package leaks handles, prevents node from exiting

[dcposch]

Describe the bug

My Mocha unit tests hang unless I specify --exit to kill the test process after each suite.

It looks like this may be because Semaphore leaks some resources.

To Reproduce

Write any test or script that verifies a Semaphore proof. At the end, add:

const foo = (process as any)._getActiveHandles();
console.log(foo);

You'll see that this includes a bunch of mysterious MessagePort handles.

Expected behavior

Should show exactly two handles, corresponding to stdin/stdout.

Technologies (please complete the following information):

• Node.js version 20
• NPM version 9.6.4
• Solidity version N/A

[dcposch]

Using @semaphore-protocol/{group,identity,proof} version 3.2.3

[vplasencia]

Hello @dcposch! It seems to be related to snarkjs which is used in the @semaphore-protocol/proof package to generate and verify a proof.

[cedoor]

#736 (comment)

This issue is related to snarkjs, but Semaphore could provide a function to "terminate" it.

[Chirag-S-Kotian]

is it solved or not?

[cedoor]

Hi @Chirag-S-Kotian, we are actually going to close this issue. Devs can use ffjavascript to get the curve and terminate it:

semaphore/packages/proof/tests/index.test.ts

Line 18 in 3ed6c38

curve = await getCurveFromName("bn128")

We'll add documentation to explain how to solve this issue.

Re: #897