GitStudio in 14 languages: the extensions and the desktop app

.github/workflows/ci.yml

@@ -78,13 +78,13 @@ jobs:
       - name: Engine purity guard
         run: npm run check-purity
 
-      # Every message the code asks for is in the English source bundle (a new
-      # l10n.t() that nobody re-extracted fails here), and every translation
-      # covers it with the same placeholders and no added markup.
+      # Every message the code asks for is in its product's English source
+      # bundle (a new l10n.t() that nobody re-extracted fails here), and every
+      # translation covers it with the same placeholders and no added markup.
       - name: Translations are complete
         run: |
           node scripts/i18n/bundle-nls.mjs --write
-          git diff --exit-code -- apps/extension/l10n/bundle.l10n.json
+          git diff --exit-code -- apps/extension/l10n apps/merge-studio/l10n apps/desktop/l10n
           npm run i18n
 
       - name: Package extension (smoke-test the build)

.gitignore

@@ -32,3 +32,6 @@ downloads/
 
 # c8 coverage reports (CI uploads them to Codecov)
 coverage/
+
+# Translation work batches (scripts/i18n/todo.mjs)
+l10n/.todo/

apps/desktop/CHANGELOG.md

@@ -9,6 +9,14 @@ The VS Code / Cursor extension has its own changelog at
 separately — desktop releases are tagged `app-v*`, extension releases `ext-v*` —
 but they share the same engine, so most Git behaviour lands in both at once.
 
+## [Unreleased]
+
+### Added
+- **GitStudio in 14 languages.** Settings ▸ Appearance ▸ Language picks one,
+  or follows your OS: Simplified and Traditional Chinese, Japanese, Korean, German, French, Spanish, Italian, Portuguese (Brazil), Russian, Turkish, Polish and Czech, besides English. A change applies after a
+  restart. Translations other than English are machine drafts — corrections
+  are welcome on GitHub.
+
 ## [2.4.0] - 2026-09-29
 
 ### Added

apps/desktop/esbuild.js

@@ -179,6 +179,29 @@ function copyStaticAssets() {
       fs.copyFileSync(abs, path.join(distDir, "renderer", dest));
     }
   }
+  writeLanguageBundles();
+}
+
+/**
+ * dist/l10n/bundle.l10n.<locale>.json: each language in the shared catalog
+ * (l10n/<locale>.json at the repository root) cut down to the messages the
+ * desktop asks for (l10n/bundle.l10n.json here, made by
+ * scripts/i18n/bundle-nls.mjs --write). main/language.ts loads one at start.
+ */
+function writeLanguageBundles() {
+  const out = path.join(distDir, "l10n");
+  fs.rmSync(out, { recursive: true, force: true });
+  fs.mkdirSync(out, { recursive: true });
+  const source = JSON.parse(fs.readFileSync(path.join(__dirname, "l10n/bundle.l10n.json"), "utf8"));
+  const catalog = path.join(repoRoot, "l10n");
+  for (const name of fs.existsSync(catalog) ? fs.readdirSync(catalog) : []) {
+    const locale = /^(.+)\.json$/.exec(name)?.[1];
+    if (!locale) continue;
+    const all = JSON.parse(fs.readFileSync(path.join(catalog, name), "utf8"));
+    const cut = {};
+    for (const key of Object.keys(source)) if (key in all) cut[key] = all[key];
+    fs.writeFileSync(path.join(out, `bundle.l10n.${locale}.json`), JSON.stringify(cut));
+  }
 }
 
 /** A plugin that re-copies the static assets after each (re)build, for watch. */

apps/desktop/harness/gen.sh

@@ -37,6 +37,15 @@ cp "$DIST/renderer.js.map" "$PAGE/renderer.js.map" 2>/dev/null || true
 cp "$HARNESS/checks.js" "$PAGE/checks.js"
 # The owner's requests, as executable clauses — see validate.mjs.
 cp "$HARNESS/requirements.js" "$PAGE/requirements.js"
+# GS_LANG=de (any locale the build has a bundle for): the page gets that
+# language's bundle the way the preload hands it over in the app.
+if [ -n "$GS_LANG" ]; then
+  BUNDLE="$HARNESS/../dist/l10n/bundle.l10n.$GS_LANG.json"
+  [ -f "$BUNDLE" ] || { echo "gen.sh: no bundle for GS_LANG=$GS_LANG ($BUNDLE)" >&2; exit 1; }
+  { printf 'window.__gitstudioLocale="%s";window.__gitstudioL10n=' "$GS_LANG"; cat "$BUNDLE"; printf ';\n'; } > "$PAGE/l10n.js"
+else
+  : > "$PAGE/l10n.js"
+fi
 # The launch screen is the app's own (dist/renderer/index.html, between its
 # launch:* markers), so every scene starts the way the app does — covered by
 # it — and every check runs after the real hand-off has removed it. Taken
@@ -72,6 +81,7 @@ HTML
     <script src="./checks.js"></script>
     <script src="./requirements.js"></script>
     <script src="./perf.js"></script>
+    <script src="./l10n.js"></script>
     <script src="./shim.js"></script>
     <script src="./renderer.js"></script>
   </body>