fix(compiler): preserve coverage pragmas in JSX

[nickshiro]

Summary

ref #2138

Preserve JSX Istanbul ignore comments when compiling component children, and annotate compiler-generated ref dispatch branches so they do not count toward coverage.

• Add /* istanbul ignore next */ annotations to compiler-generated conditional ref dispatches.
• Add regression coverage.

How did you test this change?

• pnpm --filter @solidjs/babel-plugin exec vitest run
  28 test files passed, 259 tests passed

• pnpm --filter @solidjs/babel-plugin typecheck

[changeset-bot]

🦋 Changeset detected

Latest commit: 961bd14

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 11 packages

Name	Type
@solidjs/babel-plugin	Patch
@solidjs/compiler	Patch
test-integration	Patch
@solidjs/diagnostics	Patch
@solidjs/element	Patch
@solidjs/h	Patch
@solidjs/html	Patch
@solidjs/signals	Patch
solid-js	Patch
@solidjs/universal	Patch
@solidjs/web	Patch

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[codspeed-hq]

Merging this PR will not alter performance

✅ 142 untouched benchmarks

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_{Comparing nickshiro:fix/compiler-istanbul-comments (4361585) with next (b6a90f9)}

[ryansolid]

Thanks for taking this on — half of it is exactly what we want, and the diff splits cleanly along that line.

Keep: preserving the user's own pragma. A {/* istanbul ignore next */} the author wrote in JSX should survive onto the get children() getter the compiler emits. That is comment fidelity for a deliberate annotation, and it's the right layer for it. Two asks on this half:

• Match c8 ignore alongside istanbul ignore (/^\s*(istanbul|c8)\s+ignore\b/). v8-based coverage is what most Vitest users run now, and it's the same regex.
• Oxc parity. The Babel plugin and packages/compiler share codegen expectations; the same carry-through needs to land in the native compiler with the shared fixture before this can merge.

Drop: injecting /* istanbul ignore next */ on the generated ref dispatch. This is the part that touches dom/element.ts, universal/element.ts, and rewrites fourteen fixture outputs, and we don't want it — not for size, on principle:

• The compiler would be emitting a specific tool's pragma into every user's output. That's tool knowledge in the wrong layer, and it doesn't stop at one vendor.
• Coverage of compiler-generated branches is the coverage tool's problem, and the tools have been solving it: v8 coverage with AST-aware remapping attributes back through the source map to the JSX, where there is no branch. Instrumenting post-compile output with Istanbul is the configuration that produces the phantom branches.
• Every injected comment is dev-build bytes for everyone and one more thing both compilers must mirror forever.

If real demand shows up later, an explicit opt-in is the ceiling we'd consider, but we'd rather not add it speculatively.

Also: @solidjs/web#test-types is red on this branch. It's probably the base (next moved on Sep 7); a rebase should tell.

Once it's down to the preserve half + c8 + Oxc parity, happy to merge.

— Claude via Cursor

[nickshiro]

• Removed all automatically injected coverage comments from generated ref dispatches.
• Preserved only user-authored JSX pragmas, now supporting both istanbul ignore and c8 ignore.
• Added Oxc parity for DOM, Universal, and SSR.
• Added a shared fixture consumed by the Babel and native compiler regression tests.

Thanks for your review!