feat(compiler,babel-plugin,solid): componentNames for SSR output; ssrScope swaps the id-bearing owner

[ryansolid]

Follow-up to #3433, closing the "known gap" it left: compiled SSR JSX now gets the component label, so a server finding's ownerPath reads <App> › <Page> like the client's.

Compilers

componentNames applies to the ssr generate the way it does to dom. Under the option both compilers keep the createComponent call they otherwise inline to Comp(props) and pass the source tag text:

// componentNames: true, generate: "ssr"
_$createComponent(Child, { name: "Jane" }, "Child")
_$createComponent(Ui.Button, { variant: "primary" }, "Ui.Button")
_$createComponent(_self$.Row, {}, "this.Row")

Without the option SSR still inlines — prod output is byte-identical. Universal and dynamic stay unlabelled (user-owned two-argument createComponent). @solidjs/vite-plugin already passes the option for its dev and observe postures for every generate, so app server builds (Solid Start, TanStack Start) pick this up with no config change.

• Babel: shared/component.ts — the label gate is dom || ssr; the SSR inline is skipped when labelled.
• Oxc: AstSsrTransform gains component_names / uses_create_component; jsx_tag_name becomes a shared closure-based helper so the SSR lowering reuses the same this-via-_self$ and member-tag handling as DOM.
• Fixtures: __dom_component_names_fixtures__/ssrInert → ssr, widened to the DOM fixture's shapes; the Oxc suite additionally pins that SSR without the option imports no createComponent. Parity harness green.

Runtime: ssrScope under transparent owners

Compiling the web server suite with the option (vite.config.server.mjs, i.e. the dev posture) surfaced a latent bug. The virtual hole scope swapped the current owner's id/_childCount, but content inside a hole resolves its ids by walking up past transparent owners — so with a transparent owner between the hole and its id-bearing ancestor, the reserved slot was invisible and the hole's content took fresh ids from the enclosing counter (_hk=3 where the client expects _hk=10).

This is reachable in prod today through runInServerComponentScope (its owner is transparent); with labels it would have been every component body. The scope now swaps the nearest id-bearing owner. solid/test/server/ssr-scope.spec.ts covers a plain transparent owner, the server-component scope, the labelled component owner, and nesting — all four failed before the fix.

Tests

• server-diagnostics.spec.tsx drops its mount() workaround for plain JSX. Boundaries are compiled components too, so a boundary's finding now locates as ["<App>", "<Errored>"] / ["<App>", "<Loading>"] — matching the client.
• Web server (91 files), hydrate (29), client (83) suites pass under the native compiler and JSX_COMPILER=babel; compiler vitest 5779 + cargo; babel-plugin 257; solid 618.

Out of repo

vite-plugin-solid's comment near componentNames still says "DOM-only by construction (the ssr generate ignores the flag)". Behavior there is already correct; only the comment is stale.

[changeset-bot]

🦋 Changeset detected

Latest commit: a36b9f6

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
solid-js	Patch
test-integration	Patch
@solidjs/element	Patch
@solidjs/h	Patch
@solidjs/html	Patch
@solidjs/universal	Patch
@solidjs/web	Patch
@solidjs/diagnostics	Patch
@solidjs/signals	Patch

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[coveralls]

Coverage Report for CI Build 34903669436

Coverage remained the same at 71.842%

Details

• Coverage remained the same as the base build.
• Patch coverage: No coverable lines changed in this PR.
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	1007
Covered Lines:	772
Line Coverage:	76.66%
Relevant Branches:	790
Covered Branches:	519
Branch Coverage:	65.7%
Branches in Coverage %:	Yes
Coverage Strength:	15.09 hits per line

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💛 - Coveralls

[codspeed]

Merging this PR will degrade performance by 10.43%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

❌ 1 regressed benchmark
✅ 159 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	projection derive: write one NESTED field (reference)	2.5 ms	2.8 ms	-10.43%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing ssr-component-names (a36b9f6) with next (c452850)}