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docs/ui/react/react-ui/src/components/calendar/calendar.test-fixtures.md

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+# calendar.test-fixtures
+
+## Purpose
+
+Wave-3h local test fixture that augments the chassis test i18n instance with
+the `react-ui.calendar.*` keyset. The chassis spec tests under
+`calendar.test.tsx` assert on the resolved English strings ("Calendar",
+"Previous month", "Next month") before the central wireup commit folds the
+canonical translations into the bundled `en-GB.json` source-of-truth. Once the
+wireup commit lands, the bundled keys shadow the fixture and
+`augmentI18nWithCalendarKeys` becomes a no-op re-merge — the fixture stays in
+place during the deletion window so the deletion can land as a single atomic
+cleanup pass without breaking the suite mid-rebase.
+
+## Features
+
+- Bundles localized `calendar` strings for all five chassis-supported locales
+  (`en-GB`, `zh-CN`, `ar-AE`, `cy-GB`, `ru-RU`)
+- Idempotent merge — calling the augment function twice against the same
+  instance is a no-op
+- Zero coupling to the call-site structure: the augment helper accepts any
+  `I18nInstance`
+
+## Usage
+
+### Basic Example
+
+```ts
+import { createTestI18n } from "../../../tests/setup/test-i18n.js";
+import { augmentI18nWithCalendarKeys } from "./calendar.test-fixtures.js";
+
+const i18n = await createTestI18n({ locale: "en-GB" });
+augmentI18nWithCalendarKeys(i18n);
+```
+
+### Advanced Example
+
+```ts
+import { createTestI18n } from "../../../tests/setup/test-i18n.js";
+import { augmentI18nWithCalendarKeys } from "./calendar.test-fixtures.js";
+
+for (const locale of ["en-GB", "ar-AE", "cy-GB"] as const) {
+    const i18n = await createTestI18n({ locale });
+    augmentI18nWithCalendarKeys(i18n);
+    // Assert against the locale-specific resolved strings.
+}
+```
+
+## API Reference
+
+### `augmentI18nWithCalendarKeys(i18n: I18nInstance): void`
+
+Merges the bundled `calendar` keyset into the supplied i18n instance for every
+supported locale. Returns nothing. Idempotent.
+
+## Implementation Notes
+
+The fixture is intentionally tiny — five locale × three-key bundles plus a
+loop. Once the wireup commit folds the canonical keys into the chassis
+`en-GB.json` source-of-truth, this file will be removed alongside its `.md`
+sibling, the spec test imports rewritten to drop the
+`augmentI18nWithCalendarKeys` call, and the change archived as part of the
+Wave 3h cleanup pass.