Example missing showing basic browser testing?

[NullVoxPopuli]

Describe the bug

The docs seem to be focused on node-testing, which for a lot of people is a deal breaker (need to test browser-compatibility across multiple browsers, maybe via browserstack, etc -- so the dom-mocking libraries are simply not an option).

Reproduction

visiting https://vitest.dev/, it's not clear if browser testing is supported.
I have a hunch it is, based on how I think vitest works, but I haven't played around with it yet.

System Info

n/a

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.

[antfu]

Vitest is for unit-testing on Node and does not run on browsers. We might need to document it more clearly tho

[NullVoxPopuli]

testing in browsers is hugely important for libraries and anyone who needs to ensure a certain level of cross-browser support -- why not support running in browsers?

[antfu]

We recommend using Cypress or Web Test runner for that as a complement of Vitest
https://vitest.dev/guide/comparisons.html

[NullVoxPopuli]

Those are too high level/abstracted.
The ability to do component testing is a need, and doing unit tests through cypress sounds very slow

[Smrtnyk]

there is a similar issue for jest
jestjs/jest#848
they are interested in it but it requires some bigger changes
there is also
https://github.com/4Catalyzer/karma-jest
which seems unmantained

one thing that is tricky with adding real browser env is how to isolate context for tests in there?
maybe iframe per test file? parallel browser instances?
there could be leaks if one test pollutes the env

[NullVoxPopuli]

You can't fully isolate context out of the box, but existing browser testing has techniques for managing and notifying when it does happen. (Deep recursive proxies on the grobals for dirty tracking could be an option, not sure how or if they did it pre-proxies, or even if they use proxies)

Non-dom/window using tests could run in parallel in workers, etc

[Uninen]

There's also Playwright for testing in browsers. Cypress and Playwright alone cover a humongous amount of deep and complex problems in the browser land, don't see why it would be wise to bring any of that in Vitest.

Component testing w/ Cypress, while being work in progress atm, works fine and compared to traditional e2e testing is not slow at all. I'm sure there can be innovation and optimizations made in this arena as well but IMHO if would be better suited as a plugin than a core feature for Vitest.

[NullVoxPopuli]

Playwright uses some webdriver.io stuff... which isn't what I'm after.

I mean, I guess I'll just use vite and an index.html file that includes some test setup stuff.
It's cool that this is out of scope for vitest. I just don't personally understand the resistance to this kind of testing. 🤷

[hornta]

@NullVoxPopuli I think you should reopen because this is really needed IMO. Playwright is the closest right now with their test runner and their experimental component testing. However I'm not interested in duplicating all my tests just to run them in browser.

[NullVoxPopuli]

Yeah, I started yet-another-testing tool: https://github.com/NullVoxPopuli/ember-addon-test (tho, focused more on getting ember.js stuff running with vite in a test environment. -- but it turns out that (so far) it's totally agnostic to any frontend framework, and could work with anything right now (except that I've only set this up with qunit for the actual test framework (I don't imagine it'd be hard to support mocha or similar, but qunit is what I use)).

The main thing I have to figure out so far is launching browsers automatically (and reporting test results to the cli). I started that here: NullVoxPopuli/ember-addon-test#1

but testem (which doesn't require any additional dependencies to launch browsers (such as chromedriver or geckodriver)), isn't setup to be used by other tools... so... that's dissappointing.

Would be fantastic if vitest just.. had a browser mode, but, they'd pretty much need to fragment their docs, because so much of the current vitest docs are centered around the "testing in node" story.