feat(svelte5): add support for Svelte 5 modules

[mcous]

Overview

This is a little proof of concept solution for #282. I'm a little unsure of how to add tests, given the existing testing setup. I could use guidance if anyone could offer some!

I'm currently running smoke tests locally against testing-library/svelte-testing-library#375

Change log

• Add call to compileModule if Svelte 5 is detected and the filename matches the module pattern (.svelte.js)

[sebastianrothe]

Thanks, I can have a look at it later on Thursday.

[sebastianrothe]

Looks good, I just want to make little adjustments with the imports. So it matches the current style. I will finish this until Monday. Sorry, busy week and weekend :)

[mcous]

No worries, I appreciate your time, and please adjust as you see fit! Note that I went with wildcard imports for the svelte module for technical reasons: compileModule is not an available import in Svelte earlier than v5.

I also thought it might be useful to add a really minimal Svelte 5 e2e test, let me know if that would be helpful for a follow up PR

[mcous]

@sebastianrothe I'm seeing some... interesting results while writing E2E tests against Svelte 5 in master. They're not failing, at least not in the way that I'd expect them to. It makes me want to approach this PR with a little bit of caution

I'll put up a PR with the E2E tests; it may make sense to hold off here until then

[mcous]

@sebastianrothe I traced the suspicious E2E test passing to a build issue! I appreciate the CI runs for #284, they were helpful for me to figure it out. I'm confident now that Svelte 5 modules are not currently working in svelte-jester, which is what I expect!

I think this PR is good to move forward, with the caveat that I don't have much experience using the Svelte compiler itself, so getting more eyes / testing on this might be prudent. It probably makes sense to land #284 first so that the E2E tests can be turned on in this PR