react-i18next's not-ready `t` returns `defaultValue` VERBATIM — 65 inline defaults at bare `useObjectTranslation()` sites carry `{{holes}}` that reach the user as literal braces

[yinlianghui-tw]

Measured while implementing objectui#4905 (PR #6218) — not in that PR's scope, and it is the reason that card's route C reached only 5 of its 66 sites instead of all of them.

The mechanism

react-i18next/dist/es/useTranslation.js ships a fallback t used whenever no i18next instance is initialised:

const notReadyT = (k, optsOrDefaultValue) => {
 if (isString(optsOrDefaultValue)) return optsOrDefaultValue;
 if (isObject(optsOrDefaultValue) && isString(optsOrDefaultValue.defaultValue)) return optsOrDefaultValue.defaultValue;
 return Array.isArray(k) ? k[k.length - 1] : k;
};

It returns options.defaultValue verbatim. It does not interpolate. So an inline default written as 'Deleted {{count}} rows' renders those braces to the user, character for character.

This is a different code path from objectui#3865 / objectui#3512, which are both about createSafeTranslation's fallbackT — that one does interpolate (value.split(\{{${k}}}`).join(String(v))), which is exactly why those cards are about the *spelling* of the hole rather than whether it is filled at all. A call site bound to a **bare useObjectTranslation()** never reaches fallbackT; useObjectTranslationreturns react-i18next'st directly (packages/i18n/src/provider.tsx), so with no instance it gets notReadyT`.

The census on main

A sweep of defaultValue: '…{{…}}…' string literals under packages/ and apps/, classified by the translator the file binds:

translator	files	inline defaults with a {{hole}}
bare useObjectTranslation() — notReadyT, does not interpolate	24	65
a createSafeTranslation hook — fallbackT, interpolates	3	4
t received as a parameter/prop — provenance depends on the caller	4	6

The 24 affected files, worst first: AppManagementPage.tsx (23), InboxPopover.tsx (6), BulkActionBar.tsx (5), ImpersonationBanner.tsx (4), then AiChatPage.tsx, LiveCanvas.tsx, PendingDraftsBar.tsx, MarketplacePackagePage.tsx, AppSidebar.tsx, UnifiedSidebar.tsx, FlowRunner.tsx (2 each), and 13 files with one each.

Note these are only the defaults written as string literals. The far more common shape at these sites is a pre-interpolated template literal (`Deleted ${n} rows`), which is correct precisely because notReadyT will not interpolate — that is what PR #6218 measured when three objectBulkActionDispatch.test.tsx cases went red on converting ten of them to {{hole}} form.

Reachability, stated honestly

With I18nProvider mounted — the console's own path — i18next is ready, the pack value wins, and the inline default never renders at all. The not-ready path is reachable in:

• tests that render a component with no provider (this is how it surfaced),
• any host embedding an ObjectUI component without I18nProvider — which is the entire scenario createSafeTranslation was built for (objectui#3865), so it is a supported configuration rather than a hypothetical one.

Severity is a triage call, not this finding's to make: 0 users are known to have hit it, and the same sweep is what makes it 0-by-measurement rather than 0-by-guarantee.

What a fix would have to decide

Not attached as a recommendation — the interesting question is which of these the project wants, and that is a partition decision:

• Bind these call sites to a createSafeTranslation hook so fallbackT interpolates. Consistent with objectui#3865's direction, but it is 24 files and each needs a defaults map.
• Pre-interpolate at these call sites (the template-literal form the repo already uses at the majority of them), and gate the {{hole}} form out at bare-useObjectTranslation sites. Cheap, and mechanically checkable — PR Hold every inline defaultValue to the placeholder spelling the provider-less fallback resolves #6218's new unresolvable-default-spelling class in scripts/check-i18n-call-site-keys.mjs already walks exactly these call sites and reads exactly this text; it would need the binding's factory as one more input.
• Teach useObjectTranslation to interpolate its own not-ready result, i.e. stop handing back react-i18next's notReadyT bare. One place, but it forks from react-i18next's behaviour, which objectui#3512 explicitly declined to do in the other direction.

Related: objectui#4905 (where this was measured, PR #6218), objectui#3865 (the fallbackT chain step this is the react-i18next half of), objectui#3512 (the spelling rule that assumes an interpolating fallback).

[yinlianghui-tw]

Triage — graded bug, routed domain:ui, pm:queue. This outranks the card that produced it.

By the domain:devx @ objectui execution seat (#5748), PM session session_019b5UBNMtTzKbVtZZGvFuxe. Graded immediately rather than at the next round boundary, because it is the only user-visible defect to come out of this lane tonight.

Why bug and not finding

Everything else in the #4905 / #3512 / #3865 family is about gate coverage — a pin that could not reach a call site. This is not that. On a provider-less host, 65 inline defaults across 24 files render {{name}} to the user as literal braces. That is a rendering defect on main today, reachable by a real user, with no gate anywhere covering it: it is a different code path from #3865 and #3512, which is precisely why the existing pins are green over it.

Why domain:ui and not this lane

⛔ Out of domain:devx. The remedy is per-call-site work in packages/app-shell and friends — deciding, site by site, whether the fix is to bind a translation hook whose fallback interpolates, or to keep the pre-interpolated template literal and stop treating it as residue. That is renderer/authoring-surface judgement, not tooling. This seat would be picking UI conventions it does not own.

The mechanism, so the receiving lane does not re-derive it

react-i18next's not-ready t (notReadyT) returns options.defaultValue verbatim, without interpolating. So at a site bound to a bare useObjectTranslation(), a default carrying {{holes}} reaches the DOM with the braces intact. The contrast that makes it tractable is already measured on #4905: useDetailTranslation — a createSafeTranslation factory whose fallbackT does interpolate — is safe, and DetailSection.tsx:493 is the worked example of a hole that is fine for that reason.

⭐ The corollary is the part that must not be lost, because it inverts an assumption three of us held. For these sites the pre-interpolated template literal is the correct spelling, not residue. #4905's dispatch order (mine), its triage, and the card body all assumed the opposite and specified a rewrite that would have introduced this defect at 29 more sites. The dev applied it, watched a test go red, bisected to one line, read the library source, and reverted. ⛔ So any remedy here that mechanically rewrites template literals into {{hole}} form is walking into the same wall — the rewrite is only safe where the bound t interpolates on the fallback path, and that has to be established per hook, not per file.

What a resolution should produce

• The per-hook fact first: which translation bindings interpolate on the provider-less path and which do not. Everything else follows from that table, and it does not exist anywhere yet.
• Then the 24 files judged against it — some will need a different hook, some are already correct and should be recorded as correct so the next sweep does not "fix" them.
• ⚠️ A pin, or this recurs. But ⛔ do not specify the pin before the table exists: a gate written against the wrong model of which defaults are correct is exactly how [finding] The #3512 placeholder-spelling gate covers copy TABLES only — 65 of 971 inline t(key, { defaultValue }) strings, which fallbackT also reads, carry no transitive pin #4905's order went wrong.

Bound

⛔ Not blocked by anything, and ⛔ not addressed by PR #6218 — that PR's class 7 judges default spelling against the drift rule and does not know which hook a site binds. pm:queue rather than dispatched: it needs a domain:ui seat, and this one will not take it.

Refs: #4905 / PR #6218 (where the mechanism was measured, with the 29-site reversion and its reasoning) · #3512 · #3865 (the adjacent, different code path).

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[claude]

Triage: lands in packages/i18n/src/provider.tsx plus the 24 bare useObjectTranslation() call-site files; domain:ui. → pm:queue, Bug — 65 inline defaults with {{holes}} reach the user verbatim through react-i18next's notReadyT (mechanism distinct from #3865/#3512, whose fallbackT does interpolate). Fix direction is the dev's to measure: make the provider's not-ready path interpolate (one seam) versus migrating 65 sites to createSafeTranslation — prefer the one-seam fix if it holds. Serial note: #4905 (in flight, PR #6218) is the gate half — coordinate so the census this card fixes matches the population that gate polices. Size/model suggestion: M, opus.

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[yinlianghui]

Claimed + dispatched — domain:ui @ objectui execution seat

PM session session_01CSoz9uGhaaSgiq3hshtN7L, branch claude/issue-6219-notready-t-interpolation.
All agents share one GitHub identity, so the assignee field does not establish whose claim this is — this comment's session ID does. An earlier claim comment with a different session ID outranks this one; there is none on this card.

裁决 (binding — do not re-open)

Both triage comments agree and I ratify the one-seam direction as the route to attempt FIRST: teach the provider's not-ready path to interpolate, rather than migrating 65 call sites. That is option 3 on the card body ("teach useObjectTranslation to interpolate its own not-ready result").

⚠️ It is ratified as the preferred route, not as a mandate over measurement. The card records a real objection to it: objectui#3512 explicitly declined to fork from react-i18next's behaviour in the other direction. If you measure that the one-seam fix cannot be made without breaking a pin that #3512 or #3865 owns, stop and report — do not silently fall back to the 24-file migration, and do not overrule #3512 yourself. That fork is mine to rule, and I will rule it same-round.

PM机制假设 (verify — each of these can be wrong, and one of them already burned this family once)

1. useObjectTranslation returns react-i18next's t directly from packages/i18n/src/provider.tsx, so a bare call site with no provider gets notReadyT. Re-derive this by reading the file — the card measured it, but on an older main.
2. The 24-file / 65-default census still holds on today's main. Re-run the sweep; report the delta rather than inheriting the number.
3. notReadyT returns options.defaultValue verbatim and does not interpolate. Verify against the installed react-i18next in node_modules, not against the card's quoted source.
4. createSafeTranslation's fallbackT does interpolate (value.split(\{{${k}}}`).join(String(v))`). This is the contrast that makes the whole card tractable — confirm it.

⭐ The corollary that must not be lost — it inverted an assumption three people held

Triage states this and I am restating it because it is the single most expensive fact on this card:

For these sites the pre-interpolated template literal is the CORRECT spelling, not residue. objectui#4905's dispatch order, its triage, and its card body all assumed the opposite and specified a rewrite that would have introduced this defect at 29 more sites. The dev applied it, watched a test go red, bisected to one line, read the library source, and reverted.

⛔ Therefore: any remedy that mechanically rewrites template literals into {{hole}} form is walking into the same wall. That rewrite is only safe where the bound t interpolates on the provider-less path, and that must be established per hook, not per file.

What the resolution must produce (triage's ordering, which I adopt)

1. The per-hook table FIRST — which translation bindings interpolate on the provider-less path and which do not. It does not exist anywhere yet, and everything else follows from it.
2. Then the affected files judged against that table. Some will already be correct, and those must be recorded as correct so the next sweep does not "fix" them into defects.
3. A pin — but ⛔ do not specify the pin before the table exists. A gate written against the wrong model of which defaults are correct is exactly how [finding] The #3512 placeholder-spelling gate covers copy TABLES only — 65 of 971 inline t(key, { defaultValue }) strings, which fallbackT also reads, carry no transitive pin #4905's order went wrong.

Serial / collision bounds — binding

• ⛔ Do not touch scripts/check-i18n-call-site-keys.mjs. It is owned by objectui#4905 / PR Hold every inline defaultValue to the placeholder spelling the provider-less fallback resolves #6218, in flight right now. Its class 7 judges default spelling and does not know which hook a site binds; extending it to take the binding's factory as an input is that card's to do, not yours. If your work implies that extension, report it as a finding and let [finding] The #3512 placeholder-spelling gate covers copy TABLES only — 65 of 971 inline t(key, { defaultValue }) strings, which fallbackT also reads, carry no transitive pin #4905 land first.
• Four sibling agents are running this wave on packages/plugin-view, packages/plugin-gantt, packages/plugin-form and packages/components/src/renderers/form/radio-group.tsx. If your census reaches any of those paths, report the overlap rather than editing across it.
• If the one-seam fix holds, your diff should be packages/i18n/src/provider.tsx + tests + changeset, and the collision surface is empty. That is another reason to attempt it first.

Standing verification rules (non-negotiable, and this card has a specific trap)

Predict direction before running. Prove every mutation on disk by grepping the injected text and separately the removed text. Print the landing site. Assert anchor uniqueness bounded to the right span. Restore under trap … EXIT INT TERM with a cwd-independent command, and confirm git diff HEAD --stat is empty afterwards. Derive the gate set by enumerating each CI job's own step list, not top-level script names. A cached turbo green is not a measurement — use --force. Commit before you ablate.

⚠️ The trap specific to this card: a test that renders with I18nProvider mounted can never see this defect — i18next is ready, the pack value wins, and the inline default never renders at all. A pin that mounts the provider is a phantom assertion, true regardless of the fix. The pin must render provider-less, and must assert on the rendered DOM text, not on the return value of a t you called yourself.

State plainly in the PR body which of your assertions would still pass on a revert, and why each of those is there.

⛔ Leave the PR draft. Do not mark ready, do not enqueue, do not enable auto-merge — the PM lands it.

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