feat(i18n): add localized desktop UI

Refs #17

src/i18n/resources.test.ts

@@ -0,0 +1,111 @@
+import { describe, expect, it } from 'vitest';
+import { APP_LOCALES } from './locales';
+import { resources } from './resources';
+
+type CatalogNode = string | { readonly [key: string]: CatalogNode };
+
+const flattenCatalog = (
+  node: CatalogNode,
+  prefix = ''
+): Map<string, string> => {
+  const entries = new Map<string, string>();
+
+  if (typeof node === 'string') {
+    entries.set(prefix, node);
+    return entries;
+  }
+
+  for (const [key, value] of Object.entries(node)) {
+    const path = prefix ? `${prefix}.${key}` : key;
+    for (const [leafPath, leafValue] of flattenCatalog(value, path)) {
+      entries.set(leafPath, leafValue);
+    }
+  }
+
+  return entries;
+};
+
+const interpolationTokens = (value: string): string[] =>
+  [...value.matchAll(/\{\{([A-Za-z0-9_]+)\}\}/g)]
+    .map((match) => match[1])
+    .sort();
+
+const catalogFor = (locale: keyof typeof resources): Map<string, string> =>
+  flattenCatalog(resources[locale].common);
+
+describe('translation catalogs', () => {
+  it('registers a catalog for every supported locale', () => {
+    expect(Object.keys(resources).sort()).toEqual([...APP_LOCALES].sort());
+  });
+
+  it('keeps the English catalog free of translated-script contamination', () => {
+    const suspiciousValues = [...catalogFor('en').entries()]
+      .filter(([, value]) => /[\u0590-\u05FF\u0600-\u06FF\u0400-\u04FF\u4E00-\u9FFF]/u.test(value))
+      .map(([key, value]) => `${key} = ${JSON.stringify(value)}`);
+
+    expect(suspiciousValues).toEqual([]);
+  });
+
+  it('keeps every locale structurally identical to English', () => {
+    const englishKeys = [...catalogFor('en').keys()].sort();
+
+    for (const locale of APP_LOCALES) {
+      const localeKeys = [...catalogFor(locale).keys()].sort();
+      expect({ locale, missing: englishKeys.filter((key) => !localeKeys.includes(key)), extra: localeKeys.filter((key) => !englishKeys.includes(key)) }).toEqual({
+        locale,
+        missing: [],
+        extra: [],
+      });
+    }
+  });
+
+  it('preserves interpolation tokens exactly in every translation', () => {
+    const english = catalogFor('en');
+    const allMismatches = APP_LOCALES.flatMap((locale) => {
+      const catalog = catalogFor(locale);
+      return [...english.entries()]
+        .map(([key, englishValue]) => ({
+          locale,
+          key,
+          expected: interpolationTokens(englishValue),
+          actual: interpolationTokens(catalog.get(key) ?? ''),
+        }))
+        .filter(({ expected, actual }) => JSON.stringify(expected) !== JSON.stringify(actual));
+    });
+
+    expect(allMismatches).toEqual([]);
+  });
+
+  it('reports exact English duplicates for translation review', () => {
+    const english = catalogFor('en');
+    const duplicates = APP_LOCALES.filter((locale) => locale !== 'en').flatMap((locale) => {
+      const catalog = catalogFor(locale);
+      return [...english.entries()]
+        .filter(([key, englishValue]) => englishValue.length >= 4 && catalog.get(key) === englishValue)
+        .map(([key, value]) => ({ locale, key, value }));
+    });
+
+    const allowedExactKeys = new Set([
+      'addDownloads.cookiePlaceholder',
+      'downloadTable.interactionError',
+      'keychain.stores.windows',
+      'keychain.stores.macos',
+      'settings.common.stderr',
+      'settings.integrations.chromiumZip',
+      'settings.lookAndFeel.dracula',
+      'settings.lookAndFeel.nord',
+      'settings.network.chromeWindows',
+      'settings.network.chromeMacos',
+      'settings.network.edgeWindows',
+      'settings.network.firefoxWindows',
+      'settings.network.firefoxMacos',
+      'settings.network.safariMacos',
+    ]);
+
+    const unexpectedDuplicates = duplicates
+      .filter(({ key }) => !allowedExactKeys.has(key))
+      .map(({ locale, key, value }) => `${locale}:${key} = ${JSON.stringify(value)}`);
+
+    expect(unexpectedDuplicates).toEqual([]);
+  });
+});