fix(i18n): add 6 missing translation keys and enforce locale parity in tests

backend/chainlit/translations/ar-SA.json

@@ -68,6 +68,7 @@
     "favorites": {
       "use": "استخدام رسالة مفضلة",
       "headline": "الرسائل المفضلة",
+      "remove": "إزالة المفضلة",
       "empty": {
         "title": "لا توجد رسائل محفوظة بعد",
         "description": "ابدأ بإرسال رسالة وقم بتمييزها بنجمة أو ميّز رسالة من محادثاتك السابقة"

backend/chainlit/translations/da-DK.json

@@ -68,6 +68,7 @@
     "favorites": {
       "use": "Brug en favorit besked",
       "headline": "Favorit beskeder",
+      "remove": "Fjern favorit",
       "empty": {
         "title": "Ingen gemte prompts endnu",
         "description": "Start med at sende en prompt og markere den med en stjerne, eller vælg en prompt fra tidligere samtaler"

backend/chainlit/translations/de-DE.json

@@ -249,6 +249,12 @@
   "components": {
     "MultiSelectInput": {
       "placeholder": "Wähle aus..."
+    },
+    "DatePickerInput": {
+      "placeholder": {
+        "single": "Datum auswählen",
+        "range": "Datumsbereich auswählen"
+      }
     }
   }
 }

backend/chainlit/translations/it.json

@@ -249,6 +249,12 @@
   "components": {
     "MultiSelectInput": {
       "placeholder": "Seleziona..."
+    },
+    "DatePickerInput": {
+      "placeholder": {
+        "single": "Scegli una data",
+        "range": "Scegli un intervallo di date"
+      }
     }
   }
 }

backend/chainlit/translations/ja.json

@@ -86,6 +86,7 @@
     },
     "fileUpload": {
       "dragDrop": "ここにファイルをドラッグ＆ドロップ",
+      "browse": "ファイルを参照",
       "sizeLimit": "制限：",
       "errors": {
         "failed": "アップロードに失敗しました",

backend/chainlit/translations/ko.json

@@ -249,6 +249,12 @@
   "components": {
     "MultiSelectInput": {
       "placeholder": "선택..."
+    },
+    "DatePickerInput": {
+      "placeholder": {
+        "single": "날짜 선택",
+        "range": "날짜 범위 선택"
+      }
     }
   }
 }

backend/tests/test_translations.py

@@ -1,4 +1,6 @@
+import json
 from io import StringIO
+from pathlib import Path
 from unittest.mock import patch
 
 import pytest
@@ -384,3 +386,69 @@ def test_compare_preserves_error_order(self):
         missing_errors = [e for e in errors if "Missing" in e]
         assert len(extra_errors) == 2
         assert len(missing_errors) == 3
+
+
+# The shipped locale files, discovered at collection time so each locale gets
+# its own test id and a failure names the offending file.
+TRANSLATIONS_DIR = Path(__file__).parent.parent / "chainlit" / "translations"
+GROUND_TRUTH_LOCALE = "en-US.json"
+LOCALE_FILENAMES = sorted(path.name for path in TRANSLATIONS_DIR.glob("*.json"))
+
+
+def _load_locale(filename: str) -> dict:
+    """Load one locale file from the shipped translations directory."""
+    with open(TRANSLATIONS_DIR / filename, encoding="utf-8") as file:
+        return json.load(file)
+
+
+class TestShippedTranslationFileParity:
+    """Structural parity of the locale files actually shipped in this repo.
+
+    The suites above exercise ``compare_json_structures`` against synthetic
+    dictionaries, and ``chainlit lint-translations`` inspects a *consuming
+    app's* ``.chainlit/translations/`` rather than this directory. So nothing
+    checked the real locale files, and keys added to ``en-US.json`` could land
+    without the other locales - which is how ``components.DatePickerInput``,
+    ``chat.favorites.remove`` and ``chat.fileUpload.browse`` went missing.
+
+    ``en-US.json`` is both a locale file and the ground truth; comparing it to
+    itself is trivially clean, so it needs no special-casing here.
+    """
+
+    def test_translations_directory_is_discoverable(self):
+        """Guard against the parametrized tests passing vacuously.
+
+        If this file moves, or the translations directory is renamed,
+        ``LOCALE_FILENAMES`` would be empty and every parametrized test below
+        would silently disappear rather than fail.
+        """
+        assert TRANSLATIONS_DIR.is_dir(), (
+            f"translations directory not found at {TRANSLATIONS_DIR}"
+        )
+        assert GROUND_TRUTH_LOCALE in LOCALE_FILENAMES, (
+            f"{GROUND_TRUTH_LOCALE} missing from {TRANSLATIONS_DIR}"
+        )
+        # Two is the floor that makes a parity check meaningful at all: the
+        # ground truth plus something to compare against.
+        assert len(LOCALE_FILENAMES) > 1, (
+            f"expected multiple locale files, found {LOCALE_FILENAMES}"
+        )
+
+    @pytest.mark.parametrize("filename", LOCALE_FILENAMES)
+    def test_locale_matches_ground_truth_structure(self, filename):
+        """Every locale must carry exactly the keys in en-US.json."""
+        truth = _load_locale(GROUND_TRUTH_LOCALE)
+        errors = compare_json_structures(truth, _load_locale(filename))
+
+        assert not errors, "{} differs from {}:\n{}".format(
+            filename,
+            GROUND_TRUTH_LOCALE,
+            "\n".join(f"  {error}" for error in errors),
+        )
+
+    @pytest.mark.parametrize("filename", LOCALE_FILENAMES)
+    def test_locale_is_a_json_object(self, filename):
+        """compare_json_structures rejects non-dict input, so fail clearly."""
+        assert isinstance(_load_locale(filename), dict), (
+            f"{filename} must contain a JSON object at the top level"
+        )