feat(appearance): add composable theme package

packages/appearance/src/locales/catalogs.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, it } from "vitest"
+
+import { appearanceMessages, themeColorMessages } from "../messages"
+import { appearanceCatalogLocales } from "./catalogs"
+import { messages as enUS } from "./en-US"
+import { messages as zhHans } from "./zh-Hans"
+
+describe("appearance locale catalogs", () => {
+  it("ships every message in every built-in locale", () => {
+    const ids = [
+      ...Object.values(appearanceMessages),
+      ...Object.values(themeColorMessages),
+    ].map((descriptor) => descriptor.id)
+    const catalogs = { "en-US": enUS, "zh-Hans": zhHans }
+
+    expect(appearanceCatalogLocales).toEqual(["en-US", "zh-Hans"])
+    for (const locale of appearanceCatalogLocales) {
+      expect(Object.keys(catalogs[locale])).toHaveLength(ids.length)
+      expect(ids.every((id) => id in catalogs[locale])).toBe(true)
+    }
+  })
+})