Localization & Internationalization Testing
<default_to_action> When testing multi-language/region support:
- VERIFY translation coverage (all strings translated)
- TEST locale-specific formats (date, time, currency, numbers)
- VALIDATE RTL layout (Arabic, Hebrew)
- CHECK character encoding (UTF-8, unicode)
- 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
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
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
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
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
// 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
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 - Language accessibility
- compatibility-testing - Cross-platform i18n
- 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.