Running jest tests in `workerd` environment?

We develop a library that should work on Cloudflare Workers. We have a huge test suite, that tests its full API in all the combination we could think of. Is there a good way to run our existing jest test suite in a

workerd

workerd

like environment?

DaniFoldi•12/7/23, 6:51 PM

I have some good news for you, unit test support for workers with miniflare is in the works: workerd-runtime

To my knowledge it will be vitest-only though, so I suggest you look at migrating to it, it's faster and more modern anyways.

Jan Piotrowski (janpio)OP•12/9/23, 11:17 AM

That sounds great!

If I understand correctly, this is more or less the replacement for Miniflare 2's unit testing setup?

Our test suite is massive, including a lot of custom modifications, so migrating will be quite a challenge. But I'll bring it up.

DaniFoldi•12/9/23, 11:20 AM

Indeed, to my knowledge this will be the last piece of the v2->v3 migration, which will take advantage of vitest's new pool feature in v1

Jan Piotrowski (janpio)OP•12/9/23, 11:21 AM

Ok, so matches what I found at https://github.com/cloudflare/miniflare/tree/master/packages/vitest-environment-miniflare and read at https://github.com/cloudflare/miniflare (Warning at top of README).

GitHub

miniflare/packages/vitest-environment-miniflare at master · cloudfl...

Fully-local simulator for Cloudflare Workers. For the latest version, see https://github.com/cloudflare/workers-sdk/tree/main/packages/miniflare. - cloudflare/miniflare

GitHub

GitHub - cloudflare/miniflare: 🔥 Fully-local simulator for Cloudfla...

Fully-local simulator for Cloudflare Workers. For the latest version, see https://github.com/cloudflare/workers-sdk/tree/main/packages/miniflare. - GitHub - cloudflare/miniflare:

Fully-local si...

Jan Piotrowski (janpio)OP•12/9/23, 11:22 AM

Are the v2 miniflare docs about this Vitest setup still online somewhere?
The first link refers to https://miniflare.dev/testing/vitest, but that is a 404.
I assume that would be useful for me to get some feedback before this new work is finished.

MrBBot•12/9/23, 12:09 PM

The docs for the v2 Vitest environment are here https://legacy.miniflare.dev/testing/vitest, but the API is going to change quite a bit, so I wouldn’t start migrating to that atm.

JJan Piotrowski (janpio)That sounds great! If I understand correctly, this is more or less the replacem...

MrBBot•12/9/23, 12:12 PM

Would definitely be interested to hear any feedback/pain points you had with the Jest environment though. Still at a stage where we can make changes before we release.

MrBBot•12/9/23, 12:13 PM

Specifically interested in the custom modifications you needed to make, but anything you wish was different would be helpful.

Jan Piotrowski (janpio)OP•12/9/23, 1:55 PM

Oh sorry, that was unclear it seems:

We just have a huge Jest test setup that is pretty involved, generating tests and so on (take a look at the GH Actions runs of e.g. https://github.com/prisma/prisma/commit/ed33d55b8633f8417298e1b715c961249d046296, some docs at https://github.com/prisma/prisma/blob/main/TESTING.md)
Cloudflare Workers is a new thing for us that we now want to add to that, and I'm starting to look into how we best make that happen.

MrBBot•12/9/23, 2:04 PM

Ah I see! That makes more sense!

Jan Piotrowski (janpio)OP•12/9/23, 2:10 PM

Unfortunately also something you can probably help with less :p

Running jest tests in `workerd` environment?

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