finding: the liveness author-lint's array fan-out (`getNested`) has no warned subject left, so it is now untested

[os-zhuang]

Out-of-scope discovery from the #7069 sweep (member #6774). Filed unassigned, observation class — nothing is broken today.

Fact

lintLivenessProperties (packages/lint/src/lint-liveness-properties.ts) resolves a dotted warn-map path through getNested, which fans a path out over an array container level — so widgets.colorVariant checks every widget on a dashboard, not just widgets[0]. The docblock names the intended reach: "Container properties fan out over arrays (each flow node, each dataset measure)."

That behaviour had exactly one test, in lint-liveness-properties.test.ts:

it('fans out over EVERY widget, not just the first', …)   // the dead key sits on widgets[1]

and exactly one subject — dashboard.widgets[].colorVariant, because a warn-map entry only becomes a dotted path when it sits in a ledger row's children.

Measured across all 28 ledgers on origin/main @ 2c7e62d, the complete set of entries the lint warns on (authorWarn: true, or status: experimental) is six:

Ledger	Path	Under an array container?
dashboard.json	widgets.colorVariant	yes
agent.json	lifecycle, memory, guardrails, structuredOutput	no (top-level)
object.json	externalSharingModel	no (top-level)
tool.json	outputSchema	no (top-level)

PR for #7069 flips widgets.colorVariant to live (objectui#3799 gave it a renderer — #5010 ruling B's enforce leg), which drops its authorWarn. That leaves zero warned entries under any array container, so the fan-out assertion has no subject that can distinguish a working walk from one that never looks past index 0. The PR removes the assertion rather than rewriting it into a silence check that would pass on a broken fan-out, and records the loss in a comment pointing here.

Why it is worth recording rather than shrugging off

The mechanism is the one this repo keeps paying for: a check whose coverage lapses silently, as a side effect of good news elsewhere. Nothing goes red. The next author to touch getNested — or to add a children entry with authorWarn under an array container — gets a green suite either way, and the first symptom would be an advisory that is half-blind on every real dashboard (the exact defect the deleted test was written for, per its own comment).

It is also the shape #4956 already hit once from the other side: the ledger was correct and the lint silent, because dashboard was not registered in TYPE_COLLECTIONS.

Options, none obviously right — hence a finding, not a task

1. Make getNested testable directly. It is module-private today. Exporting it (or an @internal test seam) buys a unit test that does not depend on which ledger rows happen to warn this month. Cost: a second, ledger-independent contract on a function whose whole design is "ledger-driven, coverage grows by marking entries".
2. Let the next warned array entry re-adopt the test. Cheapest, and honest — but it is a promise nobody is holding, which is what this issue exists to stop being invisible.
3. Accept it. The fan-out is exercised in production by no one right now (zero dotted warned paths), so the untested code is also unreached code. That is a real argument, and it expires the moment option 2's entry arrives.

Refs

• packages/lint/src/lint-liveness-properties.ts — getNested, checkItem, TYPE_COLLECTIONS
• liveness: DashboardWidgetSchema 的 ~22 个 widget 级键从未被台账分类,而 dashboard.json 的 _note 声称它们已分类 #4956 (the drill that created the only subject), enforce-or-remove: DashboardWidgetSchema 的 5 个 dead 键(#4956 下钻首次给出裁决) #5010 / PR refactor(spec,lint)!: 退役 dashboard widget 的 action 三键与 aria —— 连同那道「为不存在的按钮做引用完整性」的门 (#5010) #5255 (retired four of the five warned widget keys), liveness/dashboard.json 的 colorVariant 行翻 live + 解除 PR #5255 钉的「恰好只警告 colorVariant」正向对照(objectui#3359 落地随动) #6774 (flips the fifth to live), sweep(spec): 2-item liveness-ledger follow-through sweep III — one claim, one PR, per-item checklist (#6774 #6773) #7069 (sweep)

[os-zhuang]

Finding-triage ruling: Hold (why still held): the array fan-out lost its only warned subject, so the untested code is also currently unreachable — zero authorWarn/experimental entries under any array container across the ledgers today. Restart: the next warned array entry in any ledger re-adopts the dropped assertion (lint-liveness-properties.test.ts:447-448 marks the spot) instead of trusting a green suite.

Authorization: maintainer directive (this session) —「对于issue中的findings 执行一次集中分诊，并更新issue 的状态。」Centralized pass under that directive; finding grading is normally the triage seat's single channel. Round: objectstack#4949 finding-triage, 2026-08-10.
Session: 01JaVVMrSxt7Tgi1uwEuDtH7

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[os-zhuang]

CLAIM + lane ruling — spec-lane PM seat (#6017), session session_01PiRUoQkTSBBmpyXBY3cVn2. Branch: claude/issue-7079-getnested-fanout-test. Dispatching a cloud dev session (model: Opus) under the maintainer's standing acceleration instructions.

Ruling on the card's three options: a synthetic-fixture variant of option 1 — the test constructs its own ledger row with children + authorWarn under an array container and drives it through lintLivenessProperties' public API against a synthetic stack, restoring the fan-out assertion (dead key on index 1, the original test's shape) without depending on which real ledger rows happen to warn this month AND without exporting the module-private getNested. This takes option 1's benefit (ledger-independent coverage) while avoiding its named cost (a second contract on a private function). Fallback latitude: if the public API cannot be driven with a synthetic ledger (e.g. rows are loaded only from disk), an @internal-marked test seam is acceptable — state the choice and why in the PR. Test-only card: no acceptance change, no schema edit; if the fix drifts beyond packages/lint test surfaces, STOP and report.

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[os-zhuang]

CLAIM WITHDRAWN — the race-check re-read caught a recorded disposition my claim contradicted: the 2026-08-10 00:16Z maintainer-authorized findings-triage pass ruled Hold (the untested fan-out is also currently unreachable — zero warned array entries — and lint-liveness-properties.test.ts:447-448 marks the re-adoption spot). Not overriding a recorded hold without new evidence; assignee cleared, the claim comment above is void. For the restart: the synthetic-fixture route in that comment (a test-constructed ledger row with children+authorWarn under an array container, driven through the public API) remains this seat's recommended shape when the hold's restart condition fires.

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[claude]

Findings triage (re-verify @ origin/main c6a4eeb): HOLD — the fan-out assertion is gone (replaced by the tombstone comment at lint-liveness-properties.test.ts:448), and every authorWarn string left in dashboard.json sits inside prose notes, not live entries — so there is still zero warned subject under an array container and the walk is untested. Nothing red; stays a recorded coverage lapse. finding stands.

本评论来自分诊座位 Routine（#5474 试点），不构成认领。

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[claude]

Findings triage (re-verify @ origin/main afdc6ea): HOLD — the tombstone comment still stands in place of the assertion at lint-liveness-properties.test.ts:446-450 ("The fan-out is now untested; filed as #7079"), and no new warned subject has appeared under an array container. The getNested array fan-out therefore still has no live test subject. Nothing red; a recorded coverage lapse, not a defect. finding stands.

本评论来自分诊座位 Routine（#5474 试点），不构成认领。

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Generated by Claude Code

[os-zhuang]

Findings cadence re-check @ origin/main 1530870: HOLD — finding stands.

Premise live and pinned in prose: packages/lint/src/lint-liveness-properties.test.ts:444-452 still records that widgets.colorVariant was the array fan-out's only warned dotted subject, that the fan-out assertion cannot be written against today's empty dashboard warn-map, and cites this issue by number. getNested itself unchanged at lint-liveness-properties.ts:146. Held by construction: untestable until some ledger regrows a warned path under an array container — restart condition is exactly that event.

本评论来自分诊座位 Routine（#5474 试点），不构成认领。

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Generated by Claude Code