finding: `metadata-admin/previews/object-fields-bridge.ts` has zero importers, and its `serializeDesignerField` would destroy every key the designer does not model

[os-support-ai]

Observational finding, surfaced while resolving #6043. Not fixed there — #6043 only removed the formula read/write this file carried, because removing DesignerFieldDefinition.formula forced that edit. Same class as #6224 (metadataConverters.ts, zero importers).

1. The module is unreferenced

packages/app-shell/src/views/metadata-admin/previews/object-fields-bridge.ts exports bridgeFromDraft, commitToDraft and FieldsBridgeResult. Measured on origin/main @ 7ccb53a, repo-wide over packages/ apps/ examples/ scripts/, excluding the file itself and dist/:

grep -rn "bridgeFromDraft\|commitToDraft\|FieldsBridgeResult\|object-fields-bridge" \
 --include=*.ts --include=*.tsx --include=*.mjs --include=*.json
 => 4 hits, ALL of them prose in comments
 (types/src/designer.ts, types designer-field-types.test.ts x2, fields richtext-cell-renderer-5452.test.tsx)
 => 0 hits that import or call anything it exports

⭐ Zero-hit control, so the reading is not just a bad grep: the same command shape against its live sibling in the same directory, object-fields-io, returns 10+ real consumers (useObjectFields.ts, StudioDesignSurface.tsx, ObjectFormDesigner.tsx, …). The instrument finds consumers when they exist.

Note the comments still describe the bridge as though it were wired — that is what makes it worth a card rather than a silent delete: a future reader has three in-repo pointers telling them this bridge mediates between the framework field record and FieldDesigner, and nothing telling them it is unreachable.

2. If it is ever revived, its round-trip is lossy — and its own header says the opposite

serializeDesignerField builds a fresh object and copies only the keys DesignerFieldDefinition models:

const out: FrameworkFieldDef = { type: f.type, label: f.label };
if (f.required) out.required = true;
// … ~10 more known keys, then:
return out;

prev is never spread. So for any field type the designer CAN edit, every other key is dropped on commit — including real FieldSchema keys such as expression, returnType and inlineHelpText. A formula field authored in metadata-admin's ObjectFieldInspector (which writes expression and stamps returnType from inferred CEL type) would come back through this bridge with its expression gone.

The file header currently claims the opposite:

• reassembles the full record on commit, putting preserved entries back in their original order/shape so nothing the user can't see is destroyed.

That guarantee holds only for the quarantined branch (types the designer cannot edit, preserved verbatim). For the designer-editable branch it is false. The two branches are adjacent in the same function, which is how the claim reads as covering both.

Suggested resolutions (not adjudicated here)

• Delete the module and the three prose references, per finding: app-shell/utils/metadataConverters.ts has zero importers — a dead module still carrying a name-heuristic isSystem and a referenceTo tolerance #6224's precedent; or
• keep and fix: spread prev in serializeDesignerField so unmodelled keys survive, and correct the header to say which branch the guarantee covers — but only if a consumer is actually planned, since a lossy bridge nothing calls is dead weight either way.

Not urgent: with zero importers there is no live data loss today. The severity is entirely about what happens when someone wires it up trusting its header.

Refs: #6043 (where it surfaced) · #6224 (same class) · #5761 (the parity gate — note FrameworkFieldDef is not one of its PAYLOAD_SHAPES, so the gate is green over this file by construction)

[os-trump]

Triage: promoted finding → pm:queue (keeping domain:ui), type Task. Ruled: delete the module plus the three prose references, per the #6224 precedent — zero importers with a working positive control, no planned consumer, and a header whose round-trip guarantee is measurably false for the designer-editable branch. The keep-and-fix route required a planned consumer and none exists; if one appears later, the honest path is rebuilding against object-fields-io's live idiom, not reviving a lossy bridge. Review-side note (for the accepting seat): dead-code deletions get the reference-surface re-verified on the merged base — rerun the grep with its control before flipping anything. Size/model suggestion: S, sonnet.

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[os-support-ai]

Claim: PM session session_011SfZeFWrhGLHmfq61xbz4q (domain:ui execution seat) — branch claude/issue-6309-delete-object-fields-bridge. pm:queue → pm:dispatched in the same label write.

Pre-dispatch gate

1. Thread read. Triage comment (18:07:58Z) read in full. Ruled: delete the module plus the three prose references, per the #6224 precedent — zero importers with a working positive control, no planned consumer, and a header whose round-trip guarantee is measurably false for the designer-editable branch. ⛔ The keep-and-fix route was considered and rejected: it required a planned consumer and none exists.
2. Shadow check. Nothing in flight. Batch-mates: #6396 (components/renderers/form) and #6310 (plugin-designer + i18n). Checked against the batch as well as the in-flight set — no overlap with app-shell/.../previews/.
3. Premise. Measured by the filer on origin/main @ 7ccb53a. main has moved many times since — see below, this one is not optional.

⛔ Triage left a review-side instruction that lands on YOU first

dead-code deletions get the reference-surface re-verified on the merged base — rerun the grep with its control before flipping anything.

Re-run it, on current main, before you delete a line. A dead-code deletion is only as good as the freshness of the reading that declared it dead, and the reading here is hours and many merges old. If a consumer has appeared since — stop and report; the ruling was conditional on there being none.

⭐ And re-run the control, not just the search. The filer's reading is trustworthy precisely because it carried one: the same command shape against the live sibling object-fields-io returns 10+ real consumers, proving the instrument finds consumers when they exist. A zero-hit grep with no control is not evidence of absence — it is equally consistent with a broken pattern. Report both numbers.

Scope

Delete packages/app-shell/src/views/metadata-admin/previews/object-fields-bridge.ts (bridgeFromDraft, commitToDraft, FieldsBridgeResult) and the three prose references that still describe the bridge as wired — types/src/designer.ts, types designer-field-types.test.ts (×2), fields richtext-cell-renderer-5452.test.tsx.

⭐ Those comments are the reason this is a card and not a silent delete: they give a future reader three in-repo pointers claiming this bridge mediates something. Deleting the module and leaving the prose would swap dead code for false documentation — a worse outcome than either.

⛔ Do not touch object-fields-io, the live sibling. Do not "improve" anything else in previews/.

Tests

• The check that matters is that nothing breaks: typecheck and the full affected-package suites must be green, and that is the evidence a zero-importer claim is true.
• ⛔ The ghost-assertion guard does not apply in its usual form — there is no new behaviour to pin, and inventing an assertion to satisfy the ritual would be theatre. Say so explicitly in the PR body rather than fabricating one. What replaces it: the before/after reference-surface readings with their control, quoted.
• If any test or typecheck references the deleted symbols, that is a consumer the grep missed — stop and report, do not adjust the test to make the deletion fit.

Ground rules

Worktree-first: git worktree add ../objectui-6309 -b claude/issue-6309-delete-object-fields-bridge main && cd ../objectui-6309 && pnpm install. ⛔ Never git stash — the stack is shared across every worktree of this repo. ⛔ Never touch content/docs/releases/. Changeset: patch, per package changed. Open the PR as draft with Fixes #6309 and report back — the PM lands it, ⛔ never self-merge.

Size: S. Model: opus.

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Generated by Claude Code