Vitest 2

[sheremet-va]

We wanted to start gathering feedback from users for the next major version.

Feel free to bring back proposals if you want to expand on them. If possible, create an issue for your feature and link it to this discussion so we can better track the proposal.

Timeline

We did not follow any patterns for releases before. We usually try to have a breaking change release when we feel that enough time has passed since the last big breaking change and we are sure it won't disturb the ecosystem too much. We now also have an ecosystem-ci to see if other projects are ready for the release.

We will have a 1-2 month beta period before releasing a new major version. You can follow the state of PRs and issues for the next major here: https://github.com/vitest-dev/vitest/milestone/15

Initial thoughts

We are planning to change the default pool form threads to forks:

• fix!: change default pool to 'forks' #5047

This means that the test will spawn child_processes by default instead of new Worker. This should bring more stability with a slight performance cost.

Vitest 2 will also switch to chai 5 which is now bundled as ESM:

• fix!: update dependency chai to v5 #5135

[ghiscoding]

Can we have a rough idea of when the Beta will start? It's not really obvious when v2 is expected and also if I understand correctly you guys will not follow Vite's version roadmap, is that right?

[sheremet-va]

Vite's roadmap follows Node EOL which we plan to follow, so in the future, they should line up. But currently, I think, we will release Vitest 2 before the next Vite major to improve stability with #5047.

[motss]

How about an improved experimental browser mode in v2 with access to Playwright APIs like simulating keyboard events, taking screenshots, etc?

[sheremet-va]

I am working on it here: #5097

It should be released before Vitest 2.0

[sheremet-va]

In the end, it will be part of Vitest 2.0: #5097

[sheremet-va]

The beta has been released for some time now: https://github.com/vitest-dev/vitest/releases

The current idea is to release Vitest 2.0 in June.

[charlieforward9]

Is a June release still on the table or should we expect a bit of a longer wait?

[sheremet-va]

Looks like it isn't after all 😄 I am planning to have a release this week.

[RobinTail]

Happy Sunday, @sheremet-va !
What a lovely sunny day to release Vitest 2.0 😸

[RobinTail]

In my personal competition between Vitest 2, Jest 30, typescript-eslint 8 and Express 5 — Vitest is a winner!
Thank you so much, @sheremet-va.
Legendary!

[sheremet-va]

Vitest 2.0 is out! https://github.com/vitest-dev/vitest/releases/tag/v2.0.0