[test] Fix warnings in the demos

[oliviertassinari]

Fix 4 of the 6 errors existing, what's left:

1. [Tabs] pseudo class ":first-child" is potentially unsafe #24894
2. Issue with pickers displaying a warning on the wrong mask pattern

[mui-pr-bot]

No bundle size changes

Generated by 🚫 dangerJS against 21e2d53

[oliviertassinari]

@eps1lon There is a tradeoff to make between running the visual regression tests in dev mode and having the dev warnings vs. running them in production mode and having them run faster.

In dev mode, it's about 50% slower. I would be leaning toward keeping the production mode enable, but no strong point of view.

[eps1lon]

The idea is great but the current implementation will be frustrating to debug with.

[eps1lon]

Let's follow the approach we have for the unit tests and collect all during a test, throw them in afterEach and clear them in beforeEach. That way we don't swallow console calls and make sure tests don't leak if they fail.

[oliviertassinari]

Let's follow the approach we have for the unit tests and collect all during a test, throw them in afterEach and clear them in beforeEach. That way we don't swallow console calls and make sure tests don't leak if they fail.

Haha, I'm not surprised you asked for this. The docs wasn't covering the API to stop listening to an event. But I might not have searched enough. Ok, I'm on it.

[eps1lon]

The docs wasn't covering the API to stop listening to an event.

I noticed this as well. But it should have (add|remove)Listener i.e. implement EventListener. on|off should work as well but I find their naming a bit obscure.

[oliviertassinari]

I have pushed it further. I have done my best, taking your feedback into account. If it's not good enough. I would propose I simply fix the warnings, and we can come back to adding safety in the CI later. I'm going over the time budget I can spend on this. I have tried using on/off but it wasn't delivering. It seems to create more complexity than solving any problem. For instance, we need to catch the console log that popup even before we start taking screenshots (during bootstrap).

[oliviertassinari]

I have reduced the ambition of the changes. It's about fixing existing warnings in the demos.

For the tests, it was reverted in 21e2d53. If we are happy with the approach, I can replay the commit (I personally think that it's good enough), otherwise for another time.