[code-infra] Remove userEvent export from @mui/internal-test-utils

[LukasTy]

userEvent.mousePress or userEvent.keyPress do not seem to be used in this repo.
mui-x is using those extensively and never in an environment where React < 18.

The existing function has an inconsistent return type (act returns a Promise).

Also renamed userEvent export to fireUserEvent to avoid the confusion with @testing/library/user-event and in turn errors produced by the eslint-plugin-testing-library when userEvent calls are detected (plugin assumes they are from @testing-library/user-event and complains if they are not awaited).

Based on #43313 (comment) decided to remove the userEvent export.

[mui-bot]

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[Janpot]

Are they still needed given that we also use @testing-library/user-event? It already has APIs for mouse and keyboard on board.

[LukasTy]

Are they still needed given that we also use @testing-library/user-event? It already has APIs for mouse and keyboard on board.

I've explored the option of using solely the @testing-library/user-event instead of these "fakes", but it created timeout issues in tests. 🙈
I think that such refactoring is better done separately from the ESLint plugin introduction. 👍

[Janpot]

The existing function has an inconsistent return type (act returns a Promise).

🤔 doesn't it only return a promise when called with an async function? In any case, I'd rather make those methods async and keep the act, but just calling it asynchronously.

[LukasTy]

doesn't it only return a promise when called with an async function? In any case, I'd rather make those methods async and keep the act, but just calling it asynchronously.

act in those functions returns a Promise when called in an environment with React < 18.
But AFAIK, there are no instances where tests using these functions are run on older React versions. 🤷
If you don't agree with the change, I can only keep the rename of the export, which is mainly needed for the Eslint plugin setup on mui-x. 🤔

[Janpot]

Would it make sense to just move these functions to X and remove them here? I don't see why we would use them over @testing-library/user-event.

[LukasTy]

Would it make sense to just move these functions to X and remove them here? I don't see why we would use them over @testing-library/user-event.

Great observation. 💯
I will look into that.