fix: preserve popup copy when catalogs fail

package.json

@@ -5,7 +5,7 @@
   "description": "Verstak browser capture extension for Chromium and Firefox",
   "scripts": {
     "build": "node scripts/build-extension.js",
-    "test": "node scripts/test-protocol.js && node scripts/test-i18n.js && node scripts/test-popup-settings.js && node scripts/test-background-i18n.js",
+    "test": "node scripts/test-protocol.js && node scripts/test-i18n.js && node scripts/test-popup-settings.js && node scripts/test-popup-catalog-fallback.js && node scripts/test-background-i18n.js",
     "sign:firefox": "./scripts/sign-firefox-xpi.sh",
     "release:firefox": "./scripts/release-firefox-xpi.sh"
   },

scripts/test-popup-catalog-fallback.js

@@ -0,0 +1,71 @@
+#!/usr/bin/env node
+const assert = require('assert');
+const fs = require('fs');
+const path = require('path');
+const vm = require('vm');
+
+class Element {
+  constructor(text) {
+    this.value = '';
+    this.textContent = text || '';
+    this.className = '';
+    this.files = [];
+    this.listeners = {};
+  }
+  addEventListener(type, listener) { this.listeners[type] = listener; }
+}
+
+const ids = [
+  'status', 'receiver-state', 'receiver-url', 'receiver-input', 'receiver-token-input',
+  'language-select', 'file-input', 'pending-count', 'status-dot', 'subtitle',
+  'receiver-label', 'pending-label', 'url-label', 'file-label', 'receiver-url-label',
+  'receiver-token-label', 'language-label', 'capture-page', 'capture-file', 'retry',
+  'save-settings', 'context-menu-hint', 'language-system-option', 'language-en-option',
+  'language-ru-option',
+];
+const elements = Object.fromEntries(ids.map((id) => [id, new Element()]));
+elements['capture-page'].textContent = 'Send Page';
+
+const browser = {
+  runtime: {
+    getURL(relativePath) { return `extension://${relativePath}`; },
+    sendMessage() {
+      return Promise.resolve({
+        settings: { receiverUrl: 'http://127.0.0.1/', receiverToken: '', language: 'system' },
+        pendingCount: 0,
+        status: {},
+      });
+    },
+  },
+  i18n: { getUILanguage() { return 'en-US'; } },
+};
+const document = {
+  activeElement: null,
+  documentElement: { lang: '' },
+  getElementById(id) { return elements[id]; },
+};
+const context = vm.createContext({
+  browser,
+  document,
+  navigator: { language: 'en-US' },
+  console: { warn() {}, error: console.error },
+  Promise,
+  fetch() { return Promise.reject(new Error('catalog unavailable')); },
+});
+context.globalThis = context;
+
+const root = path.resolve(__dirname, '..');
+for (const file of ['shared/i18n.js', 'shared/popup/popup.js']) {
+  vm.runInContext(fs.readFileSync(path.join(root, file), 'utf8'), context, { filename: file });
+}
+
+(async () => {
+  for (let i = 0; i < 16; i += 1) await Promise.resolve();
+  assert.strictEqual(elements['capture-page'].textContent, 'Send Page');
+  assert.strictEqual(elements['receiver-state'].textContent, 'Unknown');
+  assert.strictEqual(document.documentElement.lang, 'en');
+  console.log('browser extension popup catalog fallback tests passed');
+})().catch((error) => {
+  console.error(error);
+  process.exit(1);
+});

shared/popup/popup.js

@@ -82,7 +82,10 @@
     languageSelectEl.value = currentPreference;
     Object.keys(staticText).forEach(function (id) {
       var element = document.getElementById(id);
-      if (element) element.textContent = t(staticText[id]);
+      if (element) {
+        if (element.__verstakI18nFallback == null) element.__verstakI18nFallback = element.textContent;
+        element.textContent = t(staticText[id], null, element.__verstakI18nFallback);
+      }
     });
     applyReceiverState(currentState);
   }