fix: correctly parse each with loose parser

[paoloricciuti]

Closes #14766

This was a wild chase: initially i thought it was a problem with the language-tools but then i realised that the ast for each was incorrectly generated when in loose mode...the reason is because in the each we are relying on acorn throwing the error on parse_expression to then backtrack for situations like as { x = y }...the loose parser made this impossible and returned an incorrect identifier which in turn was screwing the language server.

This fixes it even tho I'm not a huge fun of the solution because it means we need to handle the error differently if we are in an each but i don't think there's another way.

I've added a test only in parser-modern...should i add one in legacy too?

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[jasonlyu123]

Does this also fix sveltejs/language-tools#2636? I haven't figured out if it's a compiler or a svelte2tsx issue. For some odd reason, I can only see it in some projects. But the problem is the context is null in the AST.

[paoloricciuti]

Does this also fix sveltejs/language-tools#2636? I haven't figured out if it's a compiler or a svelte2tsx issue. For some odd reason, I can only see it in some projects. But the problem is the context is null in the AST.

I suspect yes...you probably can only see it for projects that uses svelte version after the loose parser

[jasonlyu123]

The weird thing is that I can't reproduce it in the svelte test or the svelte2tsx test and all the version is 5.16.0. But it does seem to be fixed if I install the pkg.new version in the project where I can reproduce the problem. Hopely it is really fixed and not just another situation where it doesn't show up 😅

[paoloricciuti]

The weird thing is that I can't reproduce it in the svelte test or the svelte2tsx test and all the version is 5.16.0. But it does seem to be fixed if I install the pkg.new version in the project I can reproduce the problem. Hopely it is really fixed and not just another situation where it doesn't show up 😅

Yeah I think we need to add a test suite for the loose parser: svelte2tsx tests and repl run without the loose parser while the extension run with it. I had the same problem while trying to understand this bug