feat: i18n support with first translations

tests/engine/PreviewServer.test.ts

@@ -578,10 +578,10 @@ describe('PreviewServer', () => {
     expect(firstPageHtml).toContain('<h1 class="archive-heading">Meine Blog Beschreibung</h1>');
 
     const secondPageHtml = await (await fetch(`${server.getBaseUrl()}/page/2/`)).text();
-    expect(secondPageHtml).toContain('<h1 class="archive-heading">Archiv 1.1.2020 - 2.1.2020</h1>');
+    expect(secondPageHtml).toContain('<h1 class="archive-heading">Archive 1.1.2020 - 2.1.2020</h1>');
   });
 
-  it('renders month archive heading with German month name on first page', async () => {
+  it('renders month archive heading in the active render language on first page', async () => {
     const posts = [
       makePost({ id: 'm-1', slug: 'm-1', title: 'M1', content: 'Body 1', createdAt: new Date('2020-02-05T10:00:00.000Z') }),
       makePost({ id: 'm-2', slug: 'm-2', title: 'M2', content: 'Body 2', createdAt: new Date('2020-02-04T10:00:00.000Z') }),
@@ -604,7 +604,7 @@ describe('PreviewServer', () => {
     await server.start(0);
 
     const monthPageHtml = await (await fetch(`${server.getBaseUrl()}/2020/2/`)).text();
-    expect(monthPageHtml).toContain('<h1 class="archive-heading">Archiv Februar 2020</h1>');
+    expect(monthPageHtml).toContain('<h1 class="archive-heading">Archive February 2020</h1>');
   });
 
   it('renders tag heading on first page and adds date range on later pages', async () => {

tests/engine/i18nLocaleCompleteness.test.ts

@@ -0,0 +1,27 @@
+import { describe, expect, it } from 'vitest';
+import en from '../../src/main/shared/i18n/locales/en.json';
+import de from '../../src/main/shared/i18n/locales/de.json';
+import fr from '../../src/main/shared/i18n/locales/fr.json';
+import itLocale from '../../src/main/shared/i18n/locales/it.json';
+import es from '../../src/main/shared/i18n/locales/es.json';
+
+type LocaleMap = Record<string, string>;
+
+const locales: Record<string, LocaleMap> = {
+  de: de as LocaleMap,
+  fr: fr as LocaleMap,
+  it: itLocale as LocaleMap,
+  es: es as LocaleMap,
+};
+
+describe('main/shared locale completeness', () => {
+  const englishKeys = Object.keys(en as LocaleMap).sort();
+
+  it('all main/shared locales contain exactly the english key set', () => {
+    for (const [locale, messages] of Object.entries(locales)) {
+      const localeKeys = Object.keys(messages).sort();
+
+      expect(localeKeys, `Locale ${locale} is missing or has extra keys`).toEqual(englishKeys);
+    }
+  });
+});

tests/engine/i18nRenderLanguage.test.ts

@@ -0,0 +1,26 @@
+import { describe, expect, it } from 'vitest';
+import {
+  resolveSupportedRenderLanguage,
+  resolveRenderLanguageFromProjectPreferences,
+  translateRender,
+} from '../../src/main/shared/i18n';
+
+describe('render i18n', () => {
+  it('resolves rendering language from project preferences', () => {
+    expect(resolveRenderLanguageFromProjectPreferences('de')).toBe('de');
+    expect(resolveRenderLanguageFromProjectPreferences('fr-CA')).toBe('fr');
+    expect(resolveRenderLanguageFromProjectPreferences(undefined)).toBe('en');
+  });
+
+  it('normalizes render language values', () => {
+    expect(resolveSupportedRenderLanguage('it')).toBe('it');
+    expect(resolveSupportedRenderLanguage('es-AR')).toBe('es');
+    expect(resolveSupportedRenderLanguage('')).toBe('en');
+  });
+
+  it('translates render keys with fallback', () => {
+    expect(translateRender('de', 'render.pagination.newer')).toBe('neuer');
+    expect(translateRender('es', 'render.pagination.older')).toBe('más antiguo');
+    expect(translateRender('fr', 'missing.key')).toBe('missing.key');
+  });
+});