fix(example-todo): re-key the three locale bundles' 19 dotted messages ids single-segment, so all 57 strings resolve

examples/app-todo/src/translations/en.ts

@@ -85,26 +85,37 @@ export const en: TranslationData = {
       description: 'Personal task management application',
     },
   },
+  // `messages` ids are single-segment, and that is the whole contract, not a
+  // style preference: `t()` resolves a key by walking its dot path
+  // (`key.split('.')`, identically in `packages/core/src/fallbacks/memory-i18n.ts`
+  // and `packages/services/service-i18n/src/file-i18n-adapter.ts`), while
+  // `messages` is a FLAT `Record<string, string>`. So an id that merely
+  // *contains* a dot — `'common.save'` — is one key NAMED `common.save`, and
+  // `t('messages.common.save', …)` looks for a nested `common` object, finds
+  // none, and returns the key string. `messages.commonSave` resolves (#18566).
+  // Rule: `content/docs/protocol/kernel/i18n-standard.mdx`; proof that every id
+  // below reaches its string through the real `t()`:
+  // `./message-id-resolution.test.ts`.
   messages: {
-    'common.save': 'Save',
-    'common.cancel': 'Cancel',
-    'common.delete': 'Delete',
-    'common.edit': 'Edit',
-    'common.create': 'Create',
-    'common.search': 'Search',
-    'common.filter': 'Filter',
-    'common.sort': 'Sort',
-    'common.refresh': 'Refresh',
-    'common.export': 'Export',
-    'common.back': 'Back',
-    'common.confirm': 'Confirm',
-    'success.saved': 'Successfully saved',
-    'success.deleted': 'Successfully deleted',
-    'success.completed': 'Task marked as completed',
-    'confirm.delete': 'Are you sure you want to delete this task?',
-    'confirm.complete': 'Mark this task as completed?',
-    'error.required': 'This field is required',
-    'error.load_failed': 'Failed to load data',
+    commonSave: 'Save',
+    commonCancel: 'Cancel',
+    commonDelete: 'Delete',
+    commonEdit: 'Edit',
+    commonCreate: 'Create',
+    commonSearch: 'Search',
+    commonFilter: 'Filter',
+    commonSort: 'Sort',
+    commonRefresh: 'Refresh',
+    commonExport: 'Export',
+    commonBack: 'Back',
+    commonConfirm: 'Confirm',
+    successSaved: 'Successfully saved',
+    successDeleted: 'Successfully deleted',
+    successCompleted: 'Task marked as completed',
+    confirmDelete: 'Are you sure you want to delete this task?',
+    confirmComplete: 'Mark this task as completed?',
+    errorRequired: 'This field is required',
+    errorLoadFailed: 'Failed to load data',
   },
   // `validationMessages` retired in spec 17.0.0 (#4667) — no resolver ever read
   // it, so the zh-CN / ja-JP strings here were never rendered and the `en` ones

examples/app-todo/src/translations/ja-JP.ts

@@ -90,25 +90,27 @@ export const jaJP: TranslationData = {
       description: '個人タスク管理アプリケーション',
     },
   },
+  // Single-segment `messages` ids — `t()` walks the dot path, so an id
+  // containing a dot resolves to nothing; see the `en` bundle (#18566).
   messages: {
-    'common.save': '保存',
-    'common.cancel': 'キャンセル',
-    'common.delete': '削除',
-    'common.edit': '編集',
-    'common.create': '新規作成',
-    'common.search': '検索',
-    'common.filter': 'フィルター',
-    'common.sort': '並べ替え',
-    'common.refresh': '更新',
-    'common.export': 'エクスポート',
-    'common.back': '戻る',
-    'common.confirm': '確認',
-    'success.saved': '保存しました',
-    'success.deleted': '削除しました',
-    'success.completed': 'タスクを完了にしました',
-    'confirm.delete': 'このタスクを削除してもよろしいですか？',
-    'confirm.complete': 'このタスクを完了にしますか？',
-    'error.required': 'この項目は必須です',
-    'error.load_failed': 'データの読み込みに失敗しました',
+    commonSave: '保存',
+    commonCancel: 'キャンセル',
+    commonDelete: '削除',
+    commonEdit: '編集',
+    commonCreate: '新規作成',
+    commonSearch: '検索',
+    commonFilter: 'フィルター',
+    commonSort: '並べ替え',
+    commonRefresh: '更新',
+    commonExport: 'エクスポート',
+    commonBack: '戻る',
+    commonConfirm: '確認',
+    successSaved: '保存しました',
+    successDeleted: '削除しました',
+    successCompleted: 'タスクを完了にしました',
+    confirmDelete: 'このタスクを削除してもよろしいですか？',
+    confirmComplete: 'このタスクを完了にしますか？',
+    errorRequired: 'この項目は必須です',
+    errorLoadFailed: 'データの読み込みに失敗しました',
   },
 };

examples/app-todo/src/translations/message-id-resolution.test.ts

@@ -0,0 +1,110 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+import { describe, it, expect } from 'vitest';
+import { createMemoryI18n } from '@objectstack/core';
+import type { TranslationData } from '@objectstack/spec/system';
+import { en } from './en';
+import { zhCN } from './zh-CN';
+import { jaJP } from './ja-JP';
+
+/**
+ * Message-id reachability (#18566).
+ *
+ * This app's `messages` ids were authored dot-separated (`'common.save'`), and
+ * that spelling is unreachable rather than merely unconventional: `t()` resolves
+ * a key by `key.split('.')` and walking segment by segment — the same code in
+ * both shipped implementations — while `messages` is a FLAT
+ * `Record<string, string>`. `t('messages.common.save', locale)` therefore looks
+ * for a nested `common` object, finds none, and returns the key string.
+ *
+ * A reference example is what an author copies, so the repair is not asserted
+ * here, it is demonstrated: the real bundle is loaded into a real provider and
+ * every id is resolved through the public `t()` contract. The last suite is the
+ * control — it drives the OLD spelling through the same call and pins that it
+ * returns the key itself, so a green run above cannot be a green run of an
+ * assertion that could not fail.
+ *
+ * The provider driven here is the core in-memory fallback. `FileI18nAdapter`
+ * (`@objectstack/service-i18n`) is deliberately NOT imported: it would add a
+ * seventh entry to this package's shrink-only unaliased-artifact ledger
+ * (`scripts/check-test-source-alias.mjs`), whose remedy is an alias in
+ * `examples/app-todo/vitest.config.ts`. The two implementations resolve keys
+ * with the same code — `key.split('.')` walked segment by segment, in
+ * `packages/core/src/fallbacks/memory-i18n.ts` and in
+ * `packages/services/service-i18n/src/file-i18n-adapter.ts` — so what this
+ * suite proves about the ids holds for both.
+ */
+
+const BUNDLES: [string, TranslationData][] = [
+  ['en', en],
+  ['zh-CN', zhCN],
+  ['ja-JP', jaJP],
+];
+
+/** Minimal read surface — both providers implement `II18nService`. */
+interface Provider {
+  t(key: string, locale: string, params?: Record<string, unknown>): string;
+  loadTranslations(locale: string, data: Record<string, unknown>): void;
+}
+
+/**
+ * The shipped `II18nService` fallback, loaded with this app's real bundle.
+ * Constructed per call so no suite can observe another's writes.
+ */
+function providers(): [string, Provider][] {
+  const built: [string, Provider][] = [
+    ['memory-i18n (core fallback)', createMemoryI18n() as unknown as Provider],
+  ];
+  for (const [, provider] of built) {
+    for (const [locale, data] of BUNDLES) {
+      provider.loadTranslations(locale, data as unknown as Record<string, unknown>);
+    }
+  }
+  return built;
+}
+
+/** Every authored id of a locale, paired with the string it must resolve to. */
+function idsOf(data: TranslationData): [string, string][] {
+  return Object.entries(data.messages ?? {});
+}
+
+describe.each(BUNDLES)('%s — authored `messages` ids', (locale, data) => {
+  const ids = idsOf(data);
+
+  it('authors at least one message id', () => {
+    // Guards the whole file against the zero-population reading: every
+    // `it.each` below would pass vacuously on an empty `messages` block.
+    expect(ids.length).toBeGreaterThan(0);
+  });
+
+  it.each(ids.map(([id]) => id))('`%s` is single-segment', (id) => {
+    expect(
+      id.includes('.'),
+      `[${locale}] message id "${id}" contains a dot, so t('messages.${id}', '${locale}') walks into a nested object that does not exist and returns the key`,
+    ).toBe(false);
+  });
+});
+
+describe.each(providers())('%s', (_providerName, provider) => {
+  describe.each(BUNDLES)('%s', (locale, data) => {
+    it.each(idsOf(data))('t("messages.%s") resolves', (id, expected) => {
+      expect(provider.t(`messages.${id}`, locale)).toBe(expected);
+    });
+  });
+
+  it('resolves a nested group key too (positive control on the walk itself)', () => {
+    expect(provider.t('objects.todo_task.label', 'en')).toBe('Task');
+    expect(provider.t('objects.todo_task.label', 'zh-CN')).toBe('任务');
+  });
+
+  it.each([
+    'messages.common.save',
+    'messages.success.saved',
+    'messages.error.load_failed',
+  ])('the retired dotted spelling `%s` still resolves to nothing', (key) => {
+    // The control. `t()` returns the key string when the walk finds no leaf, so
+    // this is the exact symptom the dotted ids shipped with — and it is why the
+    // suite above is capable of going red if anyone re-introduces one.
+    expect(provider.t(key, 'en')).toBe(key);
+  });
+});

examples/app-todo/src/translations/zh-CN.ts

@@ -98,25 +98,27 @@ export const zhCN: TranslationData = {
       description: '个人任务管理应用',
     },
   },
+  // Single-segment `messages` ids — `t()` walks the dot path, so an id
+  // containing a dot resolves to nothing; see the `en` bundle (#18566).
   messages: {
-    'common.save': '保存',
-    'common.cancel': '取消',
-    'common.delete': '删除',
-    'common.edit': '编辑',
-    'common.create': '新建',
-    'common.search': '搜索',
-    'common.filter': '筛选',
-    'common.sort': '排序',
-    'common.refresh': '刷新',
-    'common.export': '导出',
-    'common.back': '返回',
-    'common.confirm': '确认',
-    'success.saved': '保存成功',
-    'success.deleted': '删除成功',
-    'success.completed': '任务已标记为完成',
-    'confirm.delete': '确定要删除此任务吗？',
-    'confirm.complete': '确定将此任务标记为完成？',
-    'error.required': '此字段为必填项',
-    'error.load_failed': '数据加载失败',
+    commonSave: '保存',
+    commonCancel: '取消',
+    commonDelete: '删除',
+    commonEdit: '编辑',
+    commonCreate: '新建',
+    commonSearch: '搜索',
+    commonFilter: '筛选',
+    commonSort: '排序',
+    commonRefresh: '刷新',
+    commonExport: '导出',
+    commonBack: '返回',
+    commonConfirm: '确认',
+    successSaved: '保存成功',
+    successDeleted: '删除成功',
+    successCompleted: '任务已标记为完成',
+    confirmDelete: '确定要删除此任务吗？',
+    confirmComplete: '确定将此任务标记为完成？',
+    errorRequired: '此字段为必填项',
+    errorLoadFailed: '数据加载失败',
   },
 };