test: add geocoding lang parameter unit tests

8 standalone tests covering Accept-Language header in Nominatim
requests and languageCode field in Google Places payload, for both
explicit lang values (en, de, fr) and the default fallback (en).

backend/server/test_geocoding_lang.py

@@ -0,0 +1,186 @@
+#!/usr/bin/env python3
+"""
+Standalone unit tests for geocoding lang parameter support.
+No Django project setup needed — all HTTP calls are mocked.
+
+Usage:
+    cd /home/alex/projects/voyage/backend/server
+    python3 test_geocoding_lang.py
+"""
+
+import sys
+import json
+import unittest
+from unittest.mock import patch, MagicMock
+import types
+
+# ---------------------------------------------------------------------------
+# Minimal stubs so geocoding.py can be imported without a full Django project
+# ---------------------------------------------------------------------------
+django_module = types.ModuleType("django")
+django_conf_module = types.ModuleType("django.conf")
+
+
+class _Settings:
+    GOOGLE_MAPS_API_KEY = None
+
+
+settings = _Settings()
+django_conf_module.settings = settings
+django_module.conf = django_conf_module
+sys.modules.setdefault("django", django_module)
+sys.modules.setdefault("django.conf", django_conf_module)
+
+# Stub worldtravel models (not used by the functions under test)
+for mod_name in ("worldtravel", "worldtravel.models"):
+    m = types.ModuleType(mod_name)
+    for attr in ("Region", "City", "VisitedRegion", "VisitedCity"):
+        setattr(m, attr, None)
+    sys.modules.setdefault(mod_name, m)
+
+sys.path.insert(0, "/home/alex/projects/voyage/backend/server")
+from adventures.geocoding import search_osm, search_google  # noqa: E402
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+def _mock_response(json_data, status_code=200):
+    r = MagicMock()
+    r.json.return_value = json_data
+    r.raise_for_status.return_value = None
+    r.status_code = status_code
+    return r
+
+
+_OSM_RESULT = [
+    {
+        "lat": "50.0755",
+        "lon": "14.4378",
+        "name": "Prague",
+        "display_name": "Prague, Czech Republic",
+        "type": "city",
+        "category": "place",
+        "importance": 0.9,
+        "addresstype": "city",
+    }
+]
+
+_GOOGLE_RESULT = {
+    "places": [
+        {
+            "displayName": {"text": "Prague"},
+            "formattedAddress": "Prague, Czech Republic",
+            "location": {"latitude": 50.0755, "longitude": 14.4378},
+            "types": ["locality"],
+            "rating": 4.5,
+            "userRatingCount": 1000,
+        }
+    ]
+}
+
+
+# ---------------------------------------------------------------------------
+# Tests: search_osm (Nominatim)
+# ---------------------------------------------------------------------------
+class TestSearchOsmLang(unittest.TestCase):
+    def test_explicit_lang_en(self):
+        """search_osm('Prague', lang='en') sends Accept-Language: en"""
+        with patch(
+            "requests.get", return_value=_mock_response(_OSM_RESULT)
+        ) as mock_get:
+            search_osm("Prague", lang="en")
+            headers = mock_get.call_args[1].get("headers", {})
+            self.assertEqual(headers.get("Accept-Language"), "en")
+
+    def test_explicit_lang_de(self):
+        """search_osm('Prague', lang='de') sends Accept-Language: de"""
+        with patch("requests.get", return_value=_mock_response([])) as mock_get:
+            search_osm("Prague", lang="de")
+            headers = mock_get.call_args[1].get("headers", {})
+            self.assertEqual(headers.get("Accept-Language"), "de")
+
+    def test_default_lang_is_en(self):
+        """search_osm('Prague') without lang defaults to Accept-Language: en"""
+        with patch("requests.get", return_value=_mock_response([])) as mock_get:
+            search_osm("Prague")
+            headers = mock_get.call_args[1].get("headers", {})
+            self.assertEqual(
+                headers.get("Accept-Language"),
+                "en",
+                f"Expected 'en', got {headers.get('Accept-Language')!r}",
+            )
+
+    def test_returns_list(self):
+        """search_osm returns a list"""
+        with patch("requests.get", return_value=_mock_response(_OSM_RESULT)):
+            result = search_osm("Prague", lang="en")
+            self.assertIsInstance(result, list)
+
+
+# ---------------------------------------------------------------------------
+# Tests: search_google (Google Places)
+# ---------------------------------------------------------------------------
+class TestSearchGoogleLang(unittest.TestCase):
+    def setUp(self):
+        settings.GOOGLE_MAPS_API_KEY = "test-api-key"
+
+    def tearDown(self):
+        settings.GOOGLE_MAPS_API_KEY = None
+
+    def test_explicit_lang_en(self):
+        """search_google('Prague', lang='en') posts languageCode: 'en'"""
+        with patch(
+            "requests.post", return_value=_mock_response(_GOOGLE_RESULT)
+        ) as mock_post:
+            search_google("Prague", lang="en")
+            payload = mock_post.call_args[1].get("json", {})
+            self.assertIn("languageCode", payload)
+            self.assertEqual(payload["languageCode"], "en")
+
+    def test_explicit_lang_fr(self):
+        """search_google('Prague', lang='fr') posts languageCode: 'fr'"""
+        with patch(
+            "requests.post", return_value=_mock_response(_GOOGLE_RESULT)
+        ) as mock_post:
+            search_google("Prague", lang="fr")
+            payload = mock_post.call_args[1].get("json", {})
+            self.assertEqual(payload.get("languageCode"), "fr")
+
+    def test_default_lang_is_en(self):
+        """search_google('Prague') without lang defaults to languageCode: 'en'"""
+        with patch(
+            "requests.post", return_value=_mock_response(_GOOGLE_RESULT)
+        ) as mock_post:
+            search_google("Prague")
+            payload = mock_post.call_args[1].get("json", {})
+            self.assertEqual(
+                payload.get("languageCode"),
+                "en",
+                f"Expected 'en', got {payload.get('languageCode')!r}",
+            )
+
+    def test_returns_list(self):
+        """search_google returns a list"""
+        with patch("requests.post", return_value=_mock_response(_GOOGLE_RESULT)):
+            result = search_google("Prague", lang="en")
+            self.assertIsInstance(result, list)
+
+
+# ---------------------------------------------------------------------------
+if __name__ == "__main__":
+    print("=" * 60)
+    print("Geocoding lang parameter — unit tests")
+    print("=" * 60)
+    runner = unittest.TextTestRunner(verbosity=2)
+    suite = unittest.TestLoader().loadTestsFromNames(
+        ["__main__.TestSearchOsmLang", "__main__.TestSearchGoogleLang"]
+    )
+    result = runner.run(suite)
+    print("=" * 60)
+    if result.wasSuccessful():
+        print(f"ALL {result.testsRun} TESTS PASSED ✓")
+        sys.exit(0)
+    else:
+        print(f"FAILURES: {len(result.failures)}, ERRORS: {len(result.errors)}")
+        sys.exit(1)