finding(app-shell): not one of the 15 empty-collection states under `metadata-admin/previews/` uses the shared `Empty` family — and two of them define a local component *named* `Empty` that shadows it

[os-justin]

Found while landing objectui#8520, whose ruling asked explicitly for this census: "Check what the other empty-collection states in packages/app-shell/src/views/metadata-admin/previews/ do before you pick. If its siblings already use the Empty family, match them; if they all hand-roll something different, that is a finding worth reporting." They all hand-roll. Not claimed, no assignee.

The census

Probe, run at the repo root:

git grep -n -E "\bEmpty(Header|Title|Description|Content|Media)\b" -- 'packages/app-shell/src/views/metadata-admin/previews/*'

Zero hits from @object-ui/components. Lit control in the same pathspec: git grep -c PreviewShell on the same glob fires on every preview file, so the zero is an absence, not a dead pathspec. (The trailing /* matters — 'packages/*/src' without it is a whole-path glob that matches nothing.)

Meanwhile the same probe run repo-wide returns roughly 28 call sites, including 14 files in packages/app-shell/src/views/ outside this directory. So the family is reachable and in heavy use one directory up; this subtree is the hole.

What the 15 sibling empty-collection states render instead, all of them a short sentence in a muted div:

file:line	rendered
ActionPreview.tsx:580	div.text-muted-foreground.italic — "Renders full JSON response."
AgentPreview.tsx:255	div.text-xs.text-muted-foreground.italic — the emptyHint prop
AppNavCanvas.tsx:329	div with border-dashed, text-[11px]
BookPreview.tsx:190	PreviewEmptyState (the directory's own full-canvas one)
DatasourcePreview.tsx:158	div.text-xs...italic — "No config keys set."
EmailTemplatePreview.tsx:97	div.text-muted-foreground.italic
FieldStub.tsx:204	span.text-xs.text-muted-foreground
FieldsListEditor.tsx:169	p with border-dashed, text-[11px]
FlowPreview.tsx:345	div.text-muted-foreground.italic
FlowRunsPanel.tsx:348	div.text-[10px].italic
FlowSimulatorPanel.tsx:323	div.italic.text-muted-foreground
JobPreview.tsx:356	div.text-xs.text-amber-700
PageBlockCanvas.tsx:827	div with border-dashed, text-[11px]
SkillPreview.tsx:106	div.text-xs...italic — "No tools whitelisted."
ValidationPreview.tsx:281	div.text-xs.text-amber-700

Six distinct type scales (text-xs, text-[10px], text-[11px], text-sm, unset), three colour treatments, and two different dashed-border conventions — for one visual state.

The part that will bite someone

AgentPreview.tsx:221 and ToolPreview.tsx:296 each declare a local component literally named Empty:

function Empty({ children }: { children: React.ReactNode }) {
  return <div className="text-xs text-muted-foreground italic">{children}</div>;
}

In those two files the shared Empty cannot be imported under its own name at all — the import collides with the local declaration, and there is no compiler error waiting for whoever tries, only a shadowing surprise. objectui#8520 hit exactly this and imported EmptyDescription alone to route around it.

That local Empty is also, at 16px in a 215px column, the correct weight for these panes — measured against the shared container's 118.8px in the same frame (see objectui#8525). So this is not "the previews are wrong and the family is right": the family's container is genuinely too heavy for a preview rail, and the previews grew their own lighter one because nothing lighter was exported.

What is actually being asked for

Not a mechanical sweep. The question is whether the shared family should grow a light block-level member the previews can use — at which point these 15 sites plus the two local Empty declarations converge on it — or whether PreviewShell.tsx's existing PreviewEmptyState should grow a compact variant and be the directory's single answer. Both are design calls above a dev seat.

Filed as an observation, not a defect: every one of the 15 renders readable text today, so none of them has the objectui#8491 / objectui#8504 accessibility defect. What they have is drift.

Dedup

Ran. A natural-language search_issues describing the census against this repo returns one hit, #4659, which is a closed card about unread *.component.yml metadata and unrelated. Control term InspectorSelectField returned 3 in the same session (#8450, #8488, #3306), the count objectui#8520 and objectui#8504 both recorded, so the near-zero is a reading.

Related

objectui#8520 (the card whose ruling asked for this) · objectui#8525 (the shared Empty container's override problems, measured in the same run) · objectui#8504 / objectui#8491 (the em-dash class)

[os-justin]

Ruled — the "light member" this card asks whether to grow ALREADY EXISTS, and PR #8552 shipped it

Claim: session session_01YBWFb5YgMU5dw8p2VKj16S · branch claude/issue-8526-previews-shared-empty-collection

Claimed by the domain:ui PM seat on behalf of the dev it is dispatching. The dev inherits this claim and the assignee; it posts no second claim and does not touch the assignee field.

This card was filed as a design call — "grow a light member on the shared family, or grow a compact variant of PreviewShell's PreviewEmptyState". Both options are unnecessary. Measured on merged main:

AgentPreview.tsx:49    import { cn, EmptyDescription } from '@object-ui/components';
AgentPreview.tsx:315   return <EmptyDescription className="text-xs italic">No values set.</EmptyDescription>;

PR #8552 (objectui#8520) landed EmptyDescription used alone, outside any Empty container, and measured it at 16px / 12px / start-aligned / italic — identical on all four axes to the hand-rolled div it replaced. The precedent is set, merged, and measured.

The target is therefore EmptyDescription used alone. No new member on the shared family, no PreviewShell variant, nothing lands in @object-ui/components first.

⛔ Do NOT use the Empty container. Measured on objectui#8520: at the rail's real 215px width it is 118.8px tall — 7.4× the row it replaces — and Empty's md:p-12 escape hatch does not work (that was objectui#8525, fixed in PR #8552 but the weight problem is separate).

⛔ Do NOT use EmptyValue. Its docblock scopes it to an inline placeholder for a missing cell/field value, and its aria-label resolves detail.noValue — "No value" is a false statement about an empty collection.

⚠️ Correction to this card's own census

The card says the 15 sites hand-roll "a muted sentence across six different type scales." My own sweep does not reproduce that spread — the dominant spelling is uniform:

text-xs text-muted-foreground italic    AgentPreview:222, :256 · DatasourcePreview:159 · SkillPreview:107 · ToolPreview

with a small number of genuine outliers, not six scales. Re-derive the census yourself — mine was one regex and the card's was another, and neither is authoritative. Whatever you find, print the matched lines; a count is not a reading.

The outliers are the work — do not sweep them

The uniform majority is a mechanical migration. These are not, and each needs its own sentence in the PR:

• a text-sm italic text-muted-foreground site — a different scale; changing it is a visible delta that must be argued, not averaged away
• an inline <span>…none</span> — inline, not block. This card's ruling does not cover it. An inline empty marker is a different question (and possibly EmptyValue's). Leave it and say so.
• a site wrapped in its own chrome (rounded border bg-background p-2.5) — the chrome is doing something; establish what before removing or keeping it.

⭐ Evidence bar

PR #8503, PR #8518, PR #8552 are three worked examples of exactly this migration, including how each stated its per-site visual delta — deliberate versus zero — rather than averaging. Match that.

Run the caricature, do not predict it: EmptyDescription rendered unconditionally, populated collections included. On objectui#8504 that caricature passed two of the dev's own showpiece cases; on objectui#8508 it was the explicitly-labelled non-regression axis that failed. Read failure modes, not counts.

⚠️ An assertion never observed to fail has not been tested. Three separate mechanisms hit this today: an assertion that never ran because an earlier one in the same block reddened first (objectui#8506, objectui#8514), an envelope-only pin passing on a wrong-reason refusal (objectui#8530), and a @ts-expect-error suppressing a different error (objectui#8517). Confirm each discriminating assertion actually runs in the leg it was written for.

⚠️ Do not find your assertion target by the thing you are changing — if the caricature can erase what your harness navigates by, the harness dies first and the pin measures nothing (objectui#8504). Prove it with a harness-kill leg, as objectui#8508 and objectui#8520 did.

Hazards

Reachability first — confirm @object-ui/components is already on the right tier for every package you touch and add no manifest edge; stop and report if one is needed. Run from the repo root with paths; never --no-inline-config; type-check only after building the closure; skip-changeset is a phantom label, write a real changeset; check:control-bytes does not cover zero-width spaces inside string literals; a non-zero exit can mean a wrong script name (pnpm run check:changeset-fixed → ERR_PNPM_NO_SCRIPT). git grep -- 'packages/*/src' matches nothing; use 'packages/*/src/*', and every grep that can return zero needs a lit control that fires. Restore by state after every ablation with a trap on EXIT INT TERM.

⚠️ packages/plugin-kanban/src/KanbanImpl.tsx and packages/app-shell/.../inspectors/_shared.tsx are in flight on other branches — if your census reaches them, report rather than edit.

---

Generated by Claude Code

[os-justin]

os-dev-report

{
  "issue": 8526,
  "status": "done",
  "branch": "claude/issue-8526-previews-shared-empty-collection",
  "pr": "https://github.com/objectstack-ai/objectui/pull/8569",
  "premise_still_valid": true,
  "summary": "Draft PR #8569 migrates the sixteen block-level empty-collection sentences across twelve files under metadata-admin/previews/ to the shared EmptyDescription used alone (outside any Empty container, no EmptyValue, nothing added to @object-ui/components), and deletes the two file-local components named Empty that shadowed the family in AgentPreview and ToolPreview. Every site keeps its measured effective size (text-xs at 13 sites, six explicit and seven inherited from a text-xs container; text-[10px] at the run-row step log; text-[11px] at the translation category card; text-sm at the screen body), so the per-site layout delta is zero — tailwind-merge 3.6.0 evicts the family's text-sm/relaxed for any explicit size class and keeps it for bare italic, which is why every site spells its size out. The ruling's three outliers are each handled in their own sentence in the PR: text-sm kept (it stands in for a text-sm description, not a rail row); the inline span 'none' left, plus a second inline carrier the ruling did not enumerate ('not configured', DatasourcePreview:225) also left; the chrome site turns out to be the unknown-rule-type fallback wearing the CelBlock's own box, not an empty-collection state, and is untouched. Amber warning-toned sentences, dashed drop zones, palette search empties, PreviewEmptyState/PreviewMessage sites and inline value placeholders are declared out of the migration by class. The card's premise (no preview site uses the family; two local Empty declarations shadow it) verified on main; its census and the brief's PR attribution did not — see contradicts_the_brief. Reachability: @object-ui/components is workspace:* in app-shell, no manifest edge added. Governed-surface guard on the diff paths: NOT GOVERNED. Assignee untouched; no second claim posted.",
  "tests": "Closure built first: turbo run build --filter='@object-ui/app-shell^...' → 'Tasks: 28 successful, 28 total', VERDICT command-exit 0 (lock held 191s). pnpm --filter @object-ui/app-shell type-check (source leg + tsconfig.test.json leg): exit 0 before and after, script name echoed. Pin packages/app-shell/src/views/metadata-admin/previews/emptyCollection-8526.test.tsx: 'Test Files 1 passed (1) / Tests 33 passed (33)', VERDICT command-exit 0. Importers of the touched modules (14 files, grep with firing control): 'Test Files 14 passed (14) / Tests 143 passed (143)'. Extended set (seven FlowNodeInspector tests — the one consumer of ScreenPreview outside the directory — plus two console tests naming the previews): 'Test Files 9 passed (9) / Tests 297 passed (297)'. Baseline on the unedited tree for the seven pre-existing preview harnesses: 7 files / 50 tests green. Ablation, three legs, each restored by state (git diff HEAD empty over the 12 paths AND 12/12 git hash-object equal to rev-parse HEAD:path; trap on EXIT INT TERM; mutation proven on disk both directions): LEG A fix reverted to base sha (on disk: 1 EmptyDescription tag left = the #8527 precedent, 2 local Empty declarations back) → 'Tests 16 failed | 17 passed (33)', all 16 on 'the shared EmptyDescription slot' expected truthy, 0 'Unable to find'. LEG B caricature (unconditional EmptyDescription inserted before every migrated conditional; 16 markers on disk, 0 after restore) → 'Tests 33 failed (33)', 0 harness deaths: 16 populated cases on 'expected … to be null', the whole-surface case on toHaveLength(0), 16 empty cases on the sentence mismatch. The FIRST run of leg B against the first pin version measured 8 of 17 populated cases dying on 'Unable to find an element' before their toBeNull refuser ran (the harness took children[1] as the body; the caricature's inserted sibling shifted the rows) — the pin was rewritten to container-level navigation with descendant queries (commit 61b113204) and the leg re-run; the numbers above are the re-run. LEG C harness-kill (ToolPreview section title renamed) → 'Tests 2 failed | 31 passed (33)', both 'Unable to find an element with the text: Input Parameters' — textually distinct from A and B. No dist is involved in the test legs: vitest aliases @object-ui/components and the previews to src, so ablation-dist-preflight does not apply (stated, not skipped). Lint, declared narrowing: CI's pnpm lint is turbo run lint = one 'eslint .' per package and only app-shell changed; CI-exact 'eslint .' inside packages/app-shell with --format json at 61b113204 → files linted 1110, errors 0, warnings 2925 (known-debt stream; 24 in the twelve touched files, all pre-existing, none on a changed line — verified by intersecting the JSON with git diff -U0 line ranges; 0 in the pin). Invariance: eslint --print-config on AgentPreview.tsx shows parserOptions.project undefined and projectService undefined, so the diff cannot move any untouched package's verdict. Gates, exit 0 each with their own verdict line: check:control-bytes ('scanned 6760 tracked text file(s)'), node scripts/check-changeset-presence.mjs ('12 source file(s) of 1 released package(s) changed, and this change declares 1 changeset(s)'), node scripts/check-changeset-no-major.mjs, check:vi-mock-specifiers, check:i18n-keys, check:phantom-deps. Not run locally (declared to CI): the full app-shell suite (281+ files) and the two affected example packages, which carry no test reaching these modules. CI status at report time: in_progress.",
  "mcp_calls": "2 — create_pull_request and this add_issue_comment; every base-side read (issue body and timeline, PR read-back) went through git or the public page payload channel",
  "open_questions": [],
  "contradicts_the_brief": [
    "The brief and the ruling say PR #8552 landed the EmptyDescription-alone precedent at AgentPreview:315. Git says PR #8527 (commit 5eff8b161, objectui#8520) did; PR #8552 (commit 1570eac37, objectui#8525) is the Empty container's override change. The target is unaffected.",
    "The ruling's third outlier — the site wrapped in 'rounded border bg-background p-2.5' (ValidationPreview:387) — is not an empty-collection state: it is the default arm for an unknown rule type, and its chrome is the CelBlock box (ValidationPreview:439). Left untouched rather than migrated-with-chrome.",
    "The ruling enumerates one inline carrier ('none', ValidationPreview:353); there are two — 'not configured' at DatasourcePreview:225 is the same shape. Both left, both reported in the PR.",
    "The card's 'six distinct type scales' does not reproduce once ancestors are read: text-xs at 13 of the 16 migrated sites (7 of those inherited), 10px, 11px and text-sm once each. The card's fifteen also mixes four visual classes (muted sentences, dashed drop zones, amber warnings, PreviewEmptyState, a stub-input placeholder): nine of its fifteen are in the migrated set, and eight migrated sites were not in the card's list at all."
  ],
  "out_of_scope_findings": [
    "not filed (MCP frugality per the dispatch; reported for PM triage): the inline empty markers the ruling deferred have two carriers, not one — 'none' (ValidationPreview:353) and 'not configured' (DatasourcePreview:225); an inline-marker ruling would settle both at once.",
    "not filed (reported for PM triage, observation-class): EmptyDescription in packages/components/src/custom/empty.tsx types its props as React.ComponentProps of 'p' but renders a 'div', so the ref type and element type disagree; harmless at every call site today.",
    "not filed (observation-class, design call): two further hand-rolled families sit in the same directory — nine amber warning-toned empties (JobPreview, SkillPreview, ValidationPreview, BookPreview) and five dashed drop-zone placeholders in two dashed conventions (border border-dashed vs border-2 border-dashed); neither is covered by the EmptyDescription ruling."
  ]
}

---

Generated by Claude Code

[os-justin]

Contract review — accepted. PR #8569 is out of draft and armed.

⚠️ My attribution was wrong again, and this is now a pattern with a cause

I ruled that "PR #8552 landed EmptyDescription used alone at AgentPreview:315" — in the ruling comment and again in the dispatch. Verified:

$ git log -1 -S'EmptyDescription' -- .../previews/AgentPreview.tsx
5eff8b161  fix(app-shell): AgentPreview's empty rail collection announces itself in words (#8527)

1570eac37  fix(components): make Empty's base classes override-friendly … (#8552)

The precedent is PR #8527 (objectui#8520). PR #8552 is the Empty container's override change — a different card, a different package.

That is my second wrong PR attribution in two turns; the objectui#8558 seat caught the first (I credited filter-converter.ts changes to #8512 and #8529, which never touched it). Both have the same cause: I was reading from my own running account of the session instead of from git log. A PM who has reviewed twenty PRs in a day has a memory that feels precise and is not. From here I cite a commit sha or I do not cite a PR — every claim of the form "PR #X landed Y" gets a git log -S behind it first.

Neither error changed a target, because in both cases the instruction that carried the weight was read the merged file. That is luck, not design.

⚠️ And my third outlier was not an outlier — it was not in scope at all

I described ValidationPreview:387's rounded border bg-background p-2.5 site as an empty-collection state wearing chrome, and told you to establish what the chrome does before keeping it. Measured: it is the default arm for an unknown rule type, and the chrome is the CelBlock's own box (ValidationPreview:439). Not an empty-collection state. Leaving it untouched rather than migrating-with-chrome is right, and my instruction would have led somewhere wrong.

I also enumerated one inline carrier; there are two — 'none' (ValidationPreview:353) and 'not configured' (DatasourcePreview:225), the same shape. Both correctly left.

⚠️ Both censuses were wrong, in both directions

The card said "six distinct type scales"; I said the spread looked uniform. Neither reproduces once ancestors are read: text-xs at 13 of the 16 migrated sites — 7 of those inherited from a container — plus 10px, 11px and text-sm once each. Inherited sizes are exactly what a class-string grep cannot see, which is why both of our regex-based counts were confident and wrong.

And the set membership was wrong too: nine of the card's fifteen are in the migrated set, and eight migrated sites were not in the card's list at all. The card's fifteen mixed four visual classes — muted sentences, dashed drop zones, amber warnings, PreviewEmptyState, a stub-input placeholder. Declaring those out by class rather than site-by-site is the right way to make the scope checkable.

⭐ The harness caught itself on the first caricature run

The first leg-B run measured 8 of 17 populated cases dying on "Unable to find an element" before their toBeNull refuser ran — the harness took children[1] as the body, and the caricature's inserted sibling shifted the rows.

That is the objectui#8504 lesson — the caricature erased what the harness navigated by — hitting positional navigation rather than a text anchor, which is a variant the standing rule does not name. Rewriting to container-level navigation with descendant queries and re-running (61b113204) rather than reporting the first numbers is what makes leg B's 33 failed (33), 0 harness deaths mean something.

Leg C's harness-kill failing with a textually distinct message from A and B is the proof that the anchor is real.

Accepted

• Zero per-site layout delta, held by spelling every size out — with the mechanism stated: tailwind-merge 3.6.0 evicts the family's text-sm/relaxed for an explicit size class and keeps it for bare italic. That is why the sizes are explicit rather than inherited-and-hoped.
• The two file-local Empty declarations deleted, closing the shadowing that objectui#8520 found.
• The lint narrowing justified by intersecting the ESLint JSON with git diff -U0 line ranges to show all 24 warnings in the touched files are pre-existing and none sits on a changed line — plus --print-config showing no projectService, so the diff cannot move an untouched package's verdict. That is an invariance argument, not an assurance.
• ablation-dist-preflight explicitly stated as not applicable (vitest aliases both @object-ui/components and the previews to source) rather than silently skipped.

Your three findings

I will file all three. The first two are the useful ones:

• The inline carriers want one ruling, not two cards — 'none' and 'not configured' are the same shape, and an inline-marker ruling settles both. That is the card I owe.
• EmptyDescription types its props as React.ComponentProps<'p'> but renders a div — ref type and element type disagree. Harmless at every call site today, which is exactly when it is cheap to fix and exactly when nobody does.
• The two further hand-rolled families (nine amber warning-toned empties; five dashed drop zones in two dashed conventions) are a design call, correctly not swept into a card that ruled only on muted sentences.

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Generated by Claude Code