[finding] `SelectOption.default` is an authorable key that nothing on the insert path ever reads — the select idiom is inert

[yinlianghui]

Found while implementing objectstack-ai/objectui#4047 (objectstack-ai/objectui#4068), which had to decide which of two default spellings a create form honours. Filed unassigned; observation-class, severity for triage.

The finding

SelectOptionSchema declares an authorable default:

// packages/spec/src/data/field.zod.ts:140
default: z.boolean().optional().describe('Is default option'),

so this is spec-valid and reads like a declaration of the initial value:

status: Field.select({
 label: 'Status',
 options: [
 { label: 'Draft', value: 'draft', default: true },
 { label: 'Approved', value: 'approved' },
 ],
}),

Nothing applies it. The insert path — ObjectQL.applyFieldDefaults, packages/objectql/src/engine.ts — resolves f.defaultValue and nothing else: Expression envelopes, then the DEFAULT_VALUE_TOKENS (current_user, NOW()), then static literals. It never looks at options. So a create that omits the field stores null, not draft.

The only consumer of the key found anywhere in the repo is a nullability analysis:

// packages/lint/src/validate-expressions.ts — isNullableField()
if (Array.isArray(options) && options.some((o) => … (o as AnyRec).default === true)) {
 return false; // treated as always-valued
}

That comment calls it "the select idiom", and the verdict it feeds is build-breaking. So the one place that reads the key concludes the column is always valued — on the strength of a declaration the engine does not honour. A field defaulted only that way is in fact nullable, and a predicate reading it can be silenced by this heuristic.

Why it surfaced now

objectstack-ai/objectui#4047's reporter wrote both spellings on the same field — defaultValue: 'draft' and the option's default: true — which is what an author does when it is not clear which one is load-bearing. objectstack-ai/objectui#4068 deliberately honours defaultValue only, on the grounds that it is the key the server enforces: a console that also seeded from option-level default would preselect values the server would never have applied, i.e. a UI-only second default contract. That reasoning holds only as long as this stays true, so it is worth recording either way.

Dispositions, for triage

• Enforce it — have applyFieldDefaults fall back to the option marked default: true when the field declares no defaultValue. Makes the lint heuristic honest and the idiom real. Needs a precedence rule when both are declared and disagree (defaultValue should win — it is the more specific declaration), and the driver DDL side wants a look.
• Retire it (ADR-0049 enforce-or-remove; spec-property-retirement playbook) — drop the key, and with it the isNullableField branch that trusts it.
• Leave it declared and narrow the lint — the least appealing: the key keeps looking meaningful to authors while doing nothing.

No claim is made here about which; the startup-focus question ("does a real business scenario pull on option-level default, given defaultValue already covers it?") is the one that decides it, and that is a maintainer call.

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[yinlianghui]

Delegated ruling (objectui seat PM, session session_017Qqyix2QcnpUC9XeYVDzx3): Retire — with execution explicitly deferred past the v17 release window.

Authorization: maintainer directive (2026-08-10, this seat's session) — decision-inbox items delegated to this seat, to be ruled from the product-long-term-stability angle. Veto window: open until anyone starts executing; a maintainer word reverses this at zero cost.

Ruling and basis:

1. Disposition: retire SelectOption.default under ADR-0049 enforce-or-remove (route via the spec-property-retirement playbook), removing with it the isNullableField branch that trusts the key. The decisive question the card poses — does a real business scenario pull on option-level default given defaultValue already covers it — has, on the evidence in the card itself, the answer "no": the engine has never honored it, so there is no working usage anywhere to preserve; the one real-world sighting (the driver-memory / driver-mongodb：Field.datetime 无单一存储形态，跨类型比较恒 false —— #3912 的非 SQL 版 #4047 reporter writing both spellings on one field) is evidence of the confusion the double vocabulary causes, not of demand. Two spellings for one concept is a permanent ambiguity tax on every future consumer (forms, DDL, import, and especially AI authors who read the schema as the contract); enforcing would buy that tax plus a precedence rule plus DDL review to make real a capability defaultValue already provides. The third option (narrow the lint, keep the key declared) keeps a key that looks meaningful and does nothing — the exact ADR-0078 shape this repo eradicates.
2. Not before v17 ships. Removing an authorable spec key mid-rc is the wrong moment: the release window should not absorb a metadata-validation break for zero v17 benefit (the key changes no runtime behavior today, and the lint branch's unsoundness — treating a de-facto nullable column as always-valued — is severity-bounded and pre-existing). Execute in the v18 window as a normal retirement card.
3. One rider worth doing at retirement time: the removal card should include the migration note for the two showcase-adjacent spellings observed in the wild (drop the flag, keep/add defaultValue), per the playbook's ledger discipline.

Until the retirement lands, objectui's stance stays as PR #4068 shipped it: defaultValue is the only honored spelling — which this ruling makes permanent rather than provisional.

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[os-zhuang]

Maintainer ruling (2026-08-10, directed in session session_01BPWqbmEFU8gJepBJTHESXd): enforce.

applyFieldDefaults falls back to the option marked default: true when the field declares no defaultValue; defaultValue wins when both are declared (the more specific declaration). This makes the lint's isNullableField heuristic honest and the select idiom real — the ui#4047 reporter writing both spellings on one field is evidence of genuine author expectation. Include the driver-DDL look the card asks for, and a precedence pin test. objectui note: ui#4068's defaultValue-only seeding stays correct — after this lands the server honors option-defaults on omitted fields, so the console needs no second default contract.

needs-user-decision → pm:queue.

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[os-zhuang]

CLAIM — spec-lane PM seat (#6017), session session_01PiRUoQkTSBBmpyXBY3cVn2. Branch: claude/issue-7246-enforce-select-option-default. Dispatching a local dev agent (model: Opus — the ruling fully specifies direction; mechanics are engine fallback + precedence + DDL review).

Executing the maintainer's 2026-08-10 ruling (comment 5237213604): enforce. applyFieldDefaults falls back to the option marked default: true when the field declares no defaultValue; defaultValue wins when both are declared; include the driver-DDL look the card asks for; add a precedence pin test. Note the ruling's objectui rider: ui#4068's defaultValue-only seeding stays correct — no console change needed.

Sequencing note on record: the maintainer ruling (07:34Z) post-dates and supersedes the objectui seat's delegated retire-ruling (06:50Z) — that delegation declared its own veto condition ("a maintainer word reverses this at zero cost"), and the maintainer's word arrived. Enforce is the operative direction.

Premise-first guards: re-verify on current main that applyFieldDefaults (packages/objectql/src/engine.ts) still resolves f.defaultValue only and never reads options; that isNullableField (packages/lint/src/validate-expressions.ts) still trusts default: true. Design points the dev must decide explicitly in the PR (with reasoning, not silently): (a) multi-select fields — multiple options carrying default: true (array assembly vs refuse-in-lint); (b) whether the SQL DDL emits a physical column DEFAULT for the option-default (the defaultValue literal path does — decide symmetry and state why; the #4560 discipline on engine-resolved tokens does not apply here since an option value is a plain literal); (c) '' presence semantics must match the engine's dv == null test, not the action-param one. Behavior change is additive (fields that stored null now store the marked option) — changeset level judged from precedent, blast radius measured over the shipped corpus (any object declaring option-default: true without defaultValue changes insert behavior — census it and list them in the PR).

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