# Localization Testing

> Internationalization (i18n) and localization (l10n) testing for global products including transla…

Internationalization (i18n) and localization (l10n) testing for global products including translations, locale formats, RTL languages, and cultural appropriateness. Use when launching in new markets or building multi-language products.

- Page: https://ss33.ai/skills/proffesor-for-testing/localization-testing-4924973650
- Publisher: proffesor-for-testing
- Category: [Software Development](https://ss33.ai/skills/category/software-development-t44z8z) › [Testing & QA](https://ss33.ai/skills/category/software-development-t44z8z/testing-and-qa-g56s6z)
- License: MIT
- Source: https://github.com/proffesor-for-testing/agentic-qe/blob/e5814a2f4f3d7995b87ebda9ad30e8a3d92cd555/.claude/skills/localization-testing/SKILL.md

## Skill

SKILL.md: https://ss33.ai/api/v1/ss33/download/proffesor-for-testing/localization-testing-4924973650

# Localization & Internationalization Testing

## Browser engine

Browser-driven locale checks (RTL layout diffs, language-switching flows, locale-specific screenshots) should go through the **qe-browser** fleet skill. Example:

```bash
vibium go "$BASE_URL?lang=ar"  # Arabic, RTL
vibium wait load
node .claude/skills/qe-browser/scripts/visual-diff.js --name homepage-ar-rtl
vibium go "$BASE_URL?lang=ja"  # Japanese, CJK text expansion
node .claude/skills/qe-browser/scripts/visual-diff.js --name homepage-ja
```

See `.claude/skills/qe-browser/SKILL.md` for the full reference.

<default_to_action>
When testing multi-language/region support:
1. VERIFY translation coverage (all strings translated)
2. TEST locale-specific formats (date, time, currency, numbers)
3. VALIDATE RTL layout (Arabic, Hebrew)
4. CHECK character encoding (UTF-8, unicode)
5. CONFIRM cultural appropriateness (icons, colors, content)

**Quick i18n Checklist:**
- All user-facing strings externalized
- No hardcoded text in code
- Date/time/currency formatted per locale
- RTL languages flip layout correctly
- Unicode characters display properly

**Critical Success Factors:**
- Don't hardcode strings - externalize everything
- Test with real speakers, not just translation files
- RTL requires mirrored UI layout
</default_to_action>

## Quick Reference Card

### When to Use
- Launching in new markets
- Adding language support
- Before international releases
- After UI changes

---

## Translation Coverage Testing

```javascript
test('all strings are translated', () => {
  const enKeys = Object.keys(translations.en);
  const frKeys = Object.keys(translations.fr);
  const esKeys = Object.keys(translations.es);

  // All locales have same keys
  expect(frKeys).toEqual(enKeys);
  expect(esKeys).toEqual(enKeys);
});

test('no missing translation placeholders', async ({ page }) => {
  await page.goto('/?lang=fr');
  const text = await page.textContent('body');

  // Should not see placeholder keys
  expect(text).not.toContain('translation.missing');
  expect(text).not.toMatch(/\{\{.*\}\}/); // {{key}} format
});
```

---

## Date/Time/Currency Formats

```javascript
test('date formats by locale', () => {
  const date = new Date('2025-10-24');

  expect(formatDate(date, 'en-US')).toBe('10/24/2025');
  expect(formatDate(date, 'en-GB')).toBe('24/10/2025');
  expect(formatDate(date, 'ja-JP')).toBe('2025/10/24');
});

test('currency formats by locale', () => {
  const amount = 1234.56;

  expect(formatCurrency(amount, 'en-US', 'USD')).toBe('$1,234.56');
  expect(formatCurrency(amount, 'de-DE', 'EUR')).toBe('1.234,56 €');
  expect(formatCurrency(amount, 'ja-JP', 'JPY')).toBe('¥1,235');
});
```

---

## RTL (Right-to-Left) Testing

```javascript
test('layout flips for RTL languages', async ({ page }) => {
  await page.goto('/?lang=ar'); // Arabic

  const dir = await page.locator('html').getAttribute('dir');
  expect(dir).toBe('rtl');

  // Navigation should be on right
  const nav = await page.locator('nav');
  const styles = await nav.evaluate(el =>
    window.getComputedStyle(el)
  );
  expect(styles.direction).toBe('rtl');
});

test('icons/images appropriate for RTL', async ({ page }) => {
  await page.goto('/?lang=he'); // Hebrew

  // Back arrow should point right in RTL
  const backIcon = await page.locator('.back-icon');
  expect(await backIcon.getAttribute('class')).toContain('rtl-flipped');
});
```

---

## Unicode Character Support

```javascript
test('supports unicode characters', async ({ page }) => {
  // Japanese
  await page.fill('#name', '山田太郎');
  await page.click('#submit');

  const saved = await db.users.findOne({ /* ... */ });
  expect(saved.name).toBe('山田太郎');

  // Arabic
  await page.fill('#name', 'محمد');
  // Emoji
  await page.fill('#bio', '👋🌍');

  expect(saved.bio).toBe('👋🌍');
});
```

---

## Agent-Driven Localization Testing

```typescript
// Comprehensive localization validation
await Task("Localization Testing", {
  url: 'https://example.com',
  locales: ['en-US', 'fr-FR', 'de-DE', 'ja-JP', 'ar-SA'],
  checks: ['translations', 'formats', 'rtl', 'unicode'],
  detectHardcodedStrings: true
}, "qe-test-generator");

// Returns:
// {
//   locales: 5,
//   missingTranslations: 3,
//   formatIssues: 1,
//   rtlIssues: 0,
//   hardcodedStrings: ['button.submit', 'header.title']
// }
```

---

## Agent Coordination Hints

### Memory Namespace
```
aqe/localization-testing/
├── translations/*       - Translation coverage
├── formats/*            - Locale-specific formats
├── rtl-validation/*     - RTL layout checks
└── unicode/*            - Character encoding tests
```

### Fleet Coordination
```typescript
const l10nFleet = await FleetManager.coordinate({
  strategy: 'localization-testing',
  agents: [
    'qe-test-generator',   // Generate l10n tests
    'qe-test-executor',    // Execute across locales
    'qe-visual-tester'     // RTL visual validation
  ],
  topology: 'parallel'
});
```

---

## Related Skills
- [accessibility-testing](../accessibility-testing/) - Language accessibility
- [compatibility-testing](../compatibility-testing/) - Cross-platform i18n
- [visual-testing-advanced](../visual-testing-advanced/) - RTL visual regression

---

## Remember

**With Agents:** Agents validate translation coverage, detect hardcoded strings, test locale-specific formatting, and verify RTL layouts automatically across all supported languages.