fix: nested loop protection without braces causing ReferenceError: _LP is not defined

[dsaicharan072-cmyk]

Describe the bug

When users run sketch files with nested loops that do not use braces (e.g., for (...) for (...) stmt), the preprocessor generates loop protection checks using _LP[idx] variables. However, because the inner loop is not a direct child of any BlockStatement, the preprocessor was silently dropping the var _LP0 = Date.now() variable declaration. This resulted in ReferenceError: _LP0 is not defined when executing the code in the preview.

Solution

In jsPreprocess.js:

• Track directParent (the immediate parent loop or statement) in collectLoopsToProtect.
• In injectProtection, when parentBlock.body.indexOf(loop) === -1, check if it's nested directly under directParent without braces.
• If so, wrap the parent's body in a BlockStatement containing both the prepended variable declaration and the loop itself.
• Resolved an ESLint violation (no-continue rule) by restructuring the loops collection conditional logic.

Tests

• Added regression unit tests covering nested for loops and while loops without braces inside other loops.
• All 260 client tests passed successfully.

[dsaicharan072-cmyk]

Hi @TakagiHitoshi — just following up on this PR since it's been open for a little while without review.
Quick summary for convenience: this fixes the _LP0 is not defined error reported above. The root cause was that the preprocessor's loop-protection instrumentation wasn't emitting a var _LP0 declaration when a loop wasn't a direct child of a BlockStatement (i.e. brace-less nested loops like for (...) for (...) stmt). The fix wraps the parent's body in a BlockStatement so the declaration and the loop are properly scoped together, and keeps the existing brace requirement intact per the discussion above.
Changes:

jsPreprocess.js: track directParent in collectLoopsToProtect, handle the no-braces case in injectProtection
Added regression tests for nested for/while loops without braces
Fixed a no-continue ESLint violation along the way
All 260 client tests passing

Happy to make any changes if there's a preferred approach — just let me know if there's anything blocking review (e.g. changeset, CLA, etc.) and I'll address it right away. Thanks for your time!

Resolves #4183

[inaridarkfox4231]

When submitting a pull request, it's good manner to include a reference for existing issue if it's intended to resolve that. Since a reference isn't included, I'll leave one here.

resolving issue: #4183

[dsaicharan072-cmyk]

Thanks for flagging that — good call, I should have linked it originally. I've updated the PR description to reference it.