feat(i18n): complete zh-CN hardening and locale consistency

tests/test_language_precedence.py

@@ -0,0 +1,88 @@
+import json
+import pathlib
+import re
+import subprocess
+import textwrap
+
+
+REPO_ROOT = pathlib.Path(__file__).parent.parent.resolve()
+I18N_JS = (REPO_ROOT / "static" / "i18n.js").read_text(encoding="utf-8")
+BOOT_JS = (REPO_ROOT / "static" / "boot.js").read_text(encoding="utf-8")
+PANELS_JS = (REPO_ROOT / "static" / "panels.js").read_text(encoding="utf-8")
+
+
+def _run_i18n_case(script_expr: str) -> dict:
+    wrapped_expr = f"(() => ({script_expr}))()"
+    script = textwrap.dedent(
+        f"""
+        const fs = require('fs');
+        const vm = require('vm');
+        const src = fs.readFileSync({json.dumps(str(REPO_ROOT / "static" / "i18n.js"))}, 'utf8');
+        const storage = {{}};
+        const ctx = {{
+          localStorage: {{
+            getItem: (k) => Object.prototype.hasOwnProperty.call(storage, k) ? storage[k] : null,
+            setItem: (k, v) => {{ storage[k] = String(v); }},
+          }},
+          document: {{
+            documentElement: {{ lang: '' }},
+            querySelectorAll: () => [],
+          }},
+        }};
+        vm.createContext(ctx);
+        vm.runInContext(src, ctx);
+        const out = vm.runInContext({json.dumps(wrapped_expr)}, ctx);
+        process.stdout.write(JSON.stringify(out));
+        """
+    )
+    proc = subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True)
+    return json.loads(proc.stdout)
+
+
+def test_i18n_exposes_locale_resolvers():
+    assert "function resolveLocale(" in I18N_JS
+    assert "function resolvePreferredLocale(" in I18N_JS
+
+
+def test_locale_alias_resolution_and_precedence_logic():
+    result = _run_i18n_case(
+        """
+{
+  zhCn: resolveLocale('zh-CN'),
+  zhTw: resolveLocale('zh_TW'),
+  enUs: resolveLocale('EN-us'),
+  esMx: resolveLocale('es-MX'),
+  bad: resolveLocale('xx-YY'),
+  preferred1: resolvePreferredLocale('zh-CN', 'en'),
+  preferred2: resolvePreferredLocale('xx-YY', 'zh-Hant'),
+  preferred3: resolvePreferredLocale('', 'xx-YY'),
+}
+        """
+    )
+    assert result["zhCn"] == "zh"
+    assert result["zhTw"] == "zh-Hant"
+    assert result["enUs"] == "en"
+    assert result["esMx"] == "es"
+    assert result["bad"] is None
+    assert result["preferred1"] == "zh"
+    assert result["preferred2"] == "zh-Hant"
+    assert result["preferred3"] == "en"
+
+
+def test_set_locale_normalizes_alias_and_persists_canonical_key():
+    result = _run_i18n_case(
+        """
+{
+  ...(setLocale('zh-CN'), {}),
+  saved: localStorage.getItem('hermes-lang'),
+  htmlLang: document.documentElement.lang,
+}
+        """
+    )
+    assert result["saved"] == "zh"
+    assert result["htmlLang"] == "zh-CN"
+
+
+def test_boot_and_settings_panel_use_shared_locale_precedence():
+    assert re.search(r"resolvePreferredLocale\(s\.language\s*,\s*localStorage\.getItem\('hermes-lang'\)\)", BOOT_JS)
+    assert re.search(r"resolvePreferredLocale\(settings\.language\s*,\s*localStorage\.getItem\('hermes-lang'\)\)", PANELS_JS)