[ryansolid]

Summary

Fixes #4627.

This follows a maintainer ruling from 2026-11-02 that changes the #1831 behaviour from #4401.

Why the change. While an <Errored> shows its fallback, nothing under it is on screen. Its recovery therefore re-arms the whole subtree: every <Loading> under it counts as not having shown content, even one that showed content before the error. Once the errored source has its new answer, each Loading catches what is still pending in the replacement frame. It shows its own fallback beside the recovered content ([Crash][finding related]). Before this change, the error stayed up until the nested content was ready.

Where the error still stays up (D-39, D-41):

• the errored source's own re-ask;
• a pending read directly under the <Errored> with no <Loading> between (a pending is not a value);
• a recovery that is part of a held write or action, which reveals with that hold.

Mechanism (boundaries.ts):

• isCollecting is a pure query. A <Loading> behind a shown error fallback (behindError) counts as collecting.
• The reset to not-shown happens only where a Loading actually catches (caught()), so the recovery's pending reads are caught by the inner Loading, not forwarded into the write's hold.
• In prune, caughtBelow lets an error boundary drop a reader that such a Loading catches. It applies only once the errored source has answered, is neither errored nor re-asking, and the Loading's swap is not staged in a hold.
  • That last condition is async-gen seed 3289 sass/scss support? #122. A recovery held by an action, through a latest() memo, used to attach the Loading's committed content while its swap was parked in the hold, briefly showing a bare <span></span>. The error now stays up until the action lands (D-39, D-41).
  • The regression tests are a new row in errored-recovery-fresh-loading-4627.test.ts and web/test/async-gen/e1-3289-122.spec.ts.
• The loop in caught() that recorded pending readers on error parents is gone.

F-5 gets one exception pointing to D-39, in maintainer-approved wording: behind a shown error fallback nothing is on screen, so the recovery re-arms a <Loading> there.

Rules check. Every changed pin was checked against F-1, F-4, F-5, F-12, D-39 and D-41. F-5 and D-39 are amended with the ruling. S-38 is updated in SCENARIOS.md. The rules index is regenerated.

Pins changed:

Pin	Before	Now	Rule
latest-memo-inline-parity.test.ts and web twin, #1831 rows (grouped and split)	error held until m1's re-ask lands	the inner Loading's fallback, then the content; grouped and split equal	D-39 (re-ruled), F-4
derived-store-recovery-wake.test.ts "write" and "action" (seed 3289, #1831's store twin)	error, v:5, content	error, loading, v:5, content. In "action" the error stays through the hold (D-41), and the fallback shows at the commit because an armed Loading's pending holds nothing outside it (F-4)	D-39, D-41, F-4
errored-recovery-stale-memo-4592 "inside Loading", signals and web	error until a:1 lands	loading while a:1 is out. The no-boundary rows are unchanged: the error stays	D-39, F-1
store/derived-store-heal-4451.test.ts, async-gen/e3-derived-store-heal-4451.spec.ts		updated to the re-arm screens	D-39
web/test/errored-recovery-nested-loading-4425.spec.tsx	test.fails (known bug)	passes, unpinned	D-39

How did you test this change?

• New tests/errored-recovery-fresh-loading-4627.test.ts covers the [2.0] Errored recovery waits for a flight that a fresh nested Loading in the new content should catch #4627 case and the cases where the error stays.
• Ran the targeted signals tests for errors, boundaries, loading, recovery and healing: 501 passed, 11 expected fail.
• Ran these web specs: errored-recovery-stale-memo-4592, errored-recovery-nested-loading-4425 and latest-memo-inline-parity (19 passed).
• Ran rules-index.test.ts and prettier.

---

Generated by Claude Code

[changeset-bot]

🦋 Changeset detected

Latest commit: 982be38

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

This PR includes changesets to release 15 packages

Name	Type
@solidjs/signals	Patch
test-integration	Patch
@solidjs/web	Patch
@solidjs/babel-plugin	Patch
@solidjs/compiler	Patch
@solidjs/diagnostics	Patch
@solidjs/element	Patch
@solidjs/h	Patch
@solidjs/html	Patch
solid-js	Patch
@solidjs/universal	Patch
board-example	Patch
canvas-example	Patch
server-dbmon-example	Patch
todos-server-example	Patch

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[github-actions]

Size (brotli, eager entry chunk)

scenario	head	vs base	minified vs base	minified vs recorded	cap		lazy chunks (not counted)
signals: core floor (createSignal/Memo/Effect/Root/flush)	7.42 KB	0 B	0 B	−91 B	7.43 KB	✅
signals: + createStore	15.01 KB	+1 B (+0.0%)	+69 B	+69 B	15.03 KB	✅
signals: + isPending/latest	11.86 KB	0 B	0 B	0 B	11.87 KB	✅
signals: + until/refresh (truth readers, no optimism)	8.05 KB	0 B	0 B	−84 B	8.06 KB	✅
app: render + one signal (the simple-app floor)	9.80 KB	0 B	0 B	−150 B	9.80 KB	✅
app: hydrating (no stores) with Show/For/Loading/Errored/lazy	18.93 KB	+48 B (+0.3%)	+161 B	+161 B	18.93 KB	✅	lazy-page.js 0.04 KB
app: hydrating + every store primitive family	32.95 KB	+116 B (+0.4%)	+224 B	+134 B	32.90 KB	❌ over by 50 B	lazy-page.js 0.04 KB
app: CSR with Show/For/Loading/Errored/lazy	13.63 KB	+70 B (+0.5%)	+160 B	+160 B	13.57 KB	❌ over by 57 B	lazy-page.js 0.04 KB
app: CSR, observe tier (same app on the observe artifacts)	15.38 KB	+79 B (+0.5%)	+160 B	+160 B	15.33 KB	❌ over by 54 B	lazy-page.js 0.04 KB
app: CSR, observe tier + attribution engine enabled	30.02 KB	+92 B (+0.3%)	+160 B	+160 B	29.94 KB	❌ over by 75 B	lazy-page.js 0.04 KB
app: compiled floor (one template, one text hole, one delegated click)	9.97 KB	0 B	0 B	−187 B	9.98 KB	✅
app: compiled CSR (JSX todo app: spread/merge/omit, events, class/style, keyed For, Show, Loading + lazy, store)	26.49 KB	+97 B (+0.4%)	+228 B	+133 B	26.41 KB	❌ over by 83 B	stats.js 0.18 KB
app: compiled hydrating (the same JSX todo app through hydrate(), compiled hydratable)	32.77 KB	+132 B (+0.4%)	+231 B	+135 B	32.66 KB	❌ over by 114.00000000000364 B	stats.js 0.20 KB
frames: eager client consumer (frames client + transport, lazy codec)	11.75 KB	0 B	0 B	0 B	11.77 KB	✅
page: base server components (hydrating + dynamic + frames + sf reference)	33.90 KB	+35 B (+0.1%)	+150 B	+150 B	33.91 KB	✅	assets.js 0.78 KB, decode.js 7.09 KB, lazy-page.js 0.04 KB, regions.js 1.06 KB, trace.js 9.22 KB, wire.js 3.47 KB
page: live server components (base + live/GET + action + isPending/latest)	39.81 KB	+50 B (+0.1%)	+160 B	+160 B	39.77 KB	❌ over by 39 B	assets.js 0.78 KB, decode.js 7.09 KB, lazy-page.js 0.04 KB, regions.js 1.06 KB, trace.js 9.24 KB, wire.js 3.47 KB
page: compiled base server components (the base page as JSX: templates with class/style/attributes/events, For/Show; no spread)	35.86 KB	−50 B (−0.1%)	+160 B	+160 B	35.93 KB	✅	assets.js 0.78 KB, decode.js 7.09 KB, regions.js 1.06 KB, sc-comments.js 0.20 KB, trace.js 9.17 KB, wire.js 3.47 KB
page: compiled live server components (the compiled base page + live/GET + action + isPending/latest)	43.82 KB	0 B	+160 B	+160 B	43.84 KB	✅	eager (counted): web.js 23.34 KB; assets.js 0.78 KB, decode.js 7.09 KB, regions.js 1.07 KB, sc-comments.js 0.19 KB, trace.js 9.22 KB, wire.js 3.47 KB
page: base + router (base page + @solidjs/router: createRouter, two routes, preload, useNavigate)	41.52 KB	+107 B (+0.3%)	+160 B	+160 B	41.43 KB	❌ over by 90 B	assets.js 0.78 KB, decode.js 7.09 KB, lazy-page.js 0.04 KB, regions.js 1.07 KB, server.js 1.03 KB, serverForms.js 3.58 KB, trace.js 9.20 KB, wire.js 3.48 KB
page: live + router (live page + @solidjs/router: createRouter, two routes, preload, useNavigate)	49.56 KB	+51 B (+0.1%)	+160 B	+160 B	49.53 KB	❌ over by 34 B	eager (counted): client.js 28.57 KB; assets.js 0.78 KB, decode.js 7.09 KB, lazy-page.js 0.04 KB, regions.js 1.07 KB, server.js 1.03 KB, serverForms.js 3.30 KB, trace.js 9.22 KB, wire.js 3.49 KB
server: floor (getRequestEvent + isServer)	1.27 KB	0 B	0 B	0 B	1.29 KB	✅
server: renderToString (the server-render floor)	22.86 KB	0 B	0 B	0 B	22.87 KB	✅

❌ Fails the gate

• app: hydrating + every store primitive family: over brotli cap by 50 B; minified 99,297 B vs 99,163 B recorded with the cap (+134 B) — 114 B past the 20 B minified allowance; +224 B minified over this PR's base. real growth: reduce it, or raise the cap and its recorded minified in this PR with a reason (frozen floors need Size-Exception:)
• app: CSR with Show/For/Loading/Errored/lazy: over brotli cap by 57 B; minified 37,303 B vs 37,143 B recorded with the cap (+160 B) — 140 B past the 20 B minified allowance; +160 B minified over this PR's base. real growth: reduce it, or raise the cap and its recorded minified in this PR with a reason (frozen floors need Size-Exception:)
• app: CSR, observe tier (same app on the observe artifacts): over brotli cap by 54 B; minified 42,253 B vs 42,093 B recorded with the cap (+160 B) — 140 B past the 20 B minified allowance; +160 B minified over this PR's base. real growth: reduce it, or raise the cap and its recorded minified in this PR with a reason (frozen floors need Size-Exception:)
• app: CSR, observe tier + attribution engine enabled: over brotli cap by 75 B; minified 88,582 B vs 88,422 B recorded with the cap (+160 B) — 140 B past the 20 B minified allowance; +160 B minified over this PR's base. real growth: reduce it, or raise the cap and its recorded minified in this PR with a reason (frozen floors need Size-Exception:)
• app: compiled CSR (JSX todo app: spread/merge/omit, events, class/style, keyed For, Show, Loading + lazy, store): over brotli cap by 83 B; minified 80,240 B vs 80,107 B recorded with the cap (+133 B) — 113 B past the 20 B minified allowance; +228 B minified over this PR's base. real growth: reduce it, or raise the cap and its recorded minified in this PR with a reason (frozen floors need Size-Exception:)
• app: compiled hydrating (the same JSX todo app through hydrate(), compiled hydratable): over brotli cap by 114.00000000000364 B; minified 100,960 B vs 100,825 B recorded with the cap (+135 B) — 115 B past the 20 B minified allowance; +231 B minified over this PR's base. real growth: reduce it, or raise the cap and its recorded minified in this PR with a reason (frozen floors need Size-Exception:)
• page: live server components (base + live/GET + action + isPending/latest): over brotli cap by 39 B; minified 119,903 B vs 119,743 B recorded with the cap (+160 B) — 140 B past the 20 B minified allowance; +160 B minified over this PR's base. real growth: reduce it, or raise the cap and its recorded minified in this PR with a reason (frozen floors need Size-Exception:)
• page: base + router (base page + @solidjs/router: createRouter, two routes, preload, useNavigate): over brotli cap by 90 B; minified 126,040 B vs 125,880 B recorded with the cap (+160 B) — 140 B past the 20 B minified allowance; +160 B minified over this PR's base. real growth: reduce it, or raise the cap and its recorded minified in this PR with a reason (frozen floors need Size-Exception:)
• page: live + router (live page + @solidjs/router: createRouter, two routes, preload, useNavigate): over brotli cap by 34 B; minified 145,716 B vs 145,556 B recorded with the cap (+160 B) — 140 B past the 20 B minified allowance; +160 B minified over this PR's base. real growth: reduce it, or raise the cap and its recorded minified in this PR with a reason (frozen floors need Size-Exception:)

_{Bundled with Rolldown (what Vite ships), brotli q11, decimal KB. A scenario fails only when it is over its brotli cap and its minified size is more than 20 B over the minified recorded with the cap; over the cap within that allowance is brotli layout noise and passes with a warning. Caps and their recorded minified in scripts/size/scenarios.js; the floor and page caps in floor-caps.json are frozen (lower only, or Size-Exception: in the PR body). npm run ratchet lowers caps per RC; it never raises one (scripts/size/README.md).}

[coveralls]

Coverage Report for CI Build 41545155667

Warning

Build has drifted: This PR's base is out of sync with its target branch, so coverage data may include unrelated changes.
Quick fix: rebase this PR. Learn more →

Coverage remained the same at 78.205%

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:	1369
Covered Lines:	1131
Line Coverage:	82.62%
Relevant Branches:	1104
Covered Branches:	803
Branch Coverage:	72.74%
Branches in Coverage %:	Yes
Coverage Strength:	30.1 hits per line

---

💛 - Coveralls

[ryansolid]

The Size check job is red because of this PR's own growth: +208 to +227 B minified and at most +82 B brotli on the app and page rows, 0 B on hello world. The PR is waiting on the maintainer's call on that growth. Per the batch process, fix PRs don't edit scripts/size, and the caps get re-recorded once after the merge batch.

---

Generated by Claude Code

[codspeed]

Merging this PR will degrade performance by 12.3%

2 warnings

⚠️ 2 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

⚠️ 1 benchmark with a significant change ran on different hardware

Its base and head results were measured on machines with a different CPU, core count or memory, so the change might not come from the code. Run base and head on the same runner type.

Learn more about Macro Runners

See affected benchmarks

❌ 1 regressed benchmark
✅ 199 untouched benchmarks
⏩ 5 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	projection derive: write one NESTED field (reference)	2.1 ms	2.4 ms	-12.3%

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 claude/fix-4627-errored-nested-loading (982be38) with next (3ca5262)²}

Footnotes

1. 5 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on next (efd7f7d) during the generation of this report, so 3ca5262 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[ryansolid]

The CodSpeed flag on d631d3c (projection derive: write one NESTED field (reference), −12.33%) is noise. CodSpeed reports that base and head ran on different hardware. The bench never creates a boundary, so it never reaches this PR's code in boundaries.ts. It's also a known module-size-sensitive bench that swings ±13 to 15% (lazy GC sweep timing), and it flagged #4633 the same way.

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Generated by Claude Code