[fix] make flask_babel.gettext() work in engine modules (L10n & threads)

incident:
  flask_babel.gettext() does not work in the engine modules.

cause:
  the request() and response() functions of the engine modules run in the
  processor, whose search() method runs in a thread and in the threads the
  context of the Flask app does not exist. The context of the Flask app is
  needed by the gettext() function for the L10n.

Solution:
  copy context of the Flask app into the threads. [1]

special case:
  We cannot equip the search() method of the processors with the decorator [1],
  because the decorator requires a context (Flask app) that does not yet exist
  at the time of the initialization of the processors (the initialization of the
  processors is part of the initialization of the Flask app).

[1] https://flask.palletsprojects.com/en/2.3.x/api/#flask.copy_current_request_context

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

4 files changed, 24 insertions, 122 deletions

diff --git a/tests/unit/settings/test_settings.yml b/tests/unit/settings/test_settings.yml
index a975c873..e0810585 100644
--- a/tests/unit/settings/test_settings.yml
+++ b/tests/unit/settings/test_settings.yml
@@ -3,3 +3,8 @@
 use_default_settings: true
 search:
   formats: [html, csv, json, rss]
+
+engines:
+  - name: general dummy
+    engine: demo_offline
+    timeout: 3
diff --git a/tests/unit/test_search.py b/tests/unit/test_search.py
index 33bf9084..11cb8d4e 100644
--- a/tests/unit/test_search.py
+++ b/tests/unit/test_search.py
@@ -43,6 +43,12 @@ class SearchQueryTestCase(SearxTestCase):
 
 
 class SearchTestCase(SearxTestCase):
+    def setUp(self):
+
+        from searx import webapp  # pylint disable=import-outside-toplevel
+
+        self.app = webapp.app
+
     @classmethod
     def setUpClass(cls):
         searx.search.initialize(TEST_ENGINES)
@@ -53,7 +59,8 @@ class SearchTestCase(SearxTestCase):
             'test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')], 'en-US', SAFESEARCH, PAGENO, None, None
         )
         search = searx.search.Search(search_query)
-        search.search()
+        with self.app.test_request_context('/search'):
+            search.search()
         self.assertEqual(search.actual_timeout, 3.0)
 
     def test_timeout_query_above_default_nomax(self):
@@ -62,7 +69,8 @@ class SearchTestCase(SearxTestCase):
             'test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')], 'en-US', SAFESEARCH, PAGENO, None, 5.0
         )
         search = searx.search.Search(search_query)
-        search.search()
+        with self.app.test_request_context('/search'):
+            search.search()
         self.assertEqual(search.actual_timeout, 3.0)
 
     def test_timeout_query_below_default_nomax(self):
@@ -71,7 +79,8 @@ class SearchTestCase(SearxTestCase):
             'test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')], 'en-US', SAFESEARCH, PAGENO, None, 1.0
         )
         search = searx.search.Search(search_query)
-        search.search()
+        with self.app.test_request_context('/search'):
+            search.search()
         self.assertEqual(search.actual_timeout, 1.0)
 
     def test_timeout_query_below_max(self):
@@ -80,7 +89,8 @@ class SearchTestCase(SearxTestCase):
             'test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')], 'en-US', SAFESEARCH, PAGENO, None, 5.0
         )
         search = searx.search.Search(search_query)
-        search.search()
+        with self.app.test_request_context('/search'):
+            search.search()
         self.assertEqual(search.actual_timeout, 5.0)
 
     def test_timeout_query_above_max(self):
@@ -89,7 +99,8 @@ class SearchTestCase(SearxTestCase):
             'test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')], 'en-US', SAFESEARCH, PAGENO, None, 15.0
         )
         search = searx.search.Search(search_query)
-        search.search()
+        with self.app.test_request_context('/search'):
+            search.search()
         self.assertEqual(search.actual_timeout, 10.0)
 
     def test_external_bang(self):
@@ -119,6 +130,7 @@ class SearchTestCase(SearxTestCase):
         )
 
         search = searx.search.Search(search_query)
-        results = search.search()
+        with self.app.test_request_context('/search'):
+            results = search.search()
         # This should not redirect
         self.assertTrue(results.redirect_url is None)
diff --git a/tests/unit/test_standalone_searx.py b/tests/unit/test_standalone_searx.py
deleted file mode 100644
index 6a450485..00000000
--- a/tests/unit/test_standalone_searx.py
+++ /dev/null
@@ -1,113 +0,0 @@
-# -*- coding: utf-8 -*-
-"""Test utils/standalone_searx.py"""
-import datetime
-import io
-import sys
-
-from mock import Mock, patch
-from nose2.tools import params
-
-from searx.search import SearchQuery, EngineRef, initialize
-from searxng_extra import standalone_searx as sas
-from tests import SearxTestCase
-
-
-class StandaloneSearx(SearxTestCase):
-    """Unit test for standalone_searx."""
-
-    @classmethod
-    def setUpClass(cls):
-        engine_list = [{'engine': 'dummy', 'name': 'engine1', 'shortcut': 'e1'}]
-
-        initialize(engine_list)
-
-    def test_parse_argument_no_args(self):
-        """Test parse argument without args."""
-        with patch.object(sys, 'argv', ['standalone_searx']), self.assertRaises(SystemExit):
-            sys.stderr = io.StringIO()
-            sas.parse_argument()
-            sys.stdout = sys.__stderr__
-
-    def test_parse_argument_basic_args(self):
-        """Test parse argument with basic args."""
-        query = 'red box'
-        exp_dict = {
-            'query': query,
-            'category': 'general',
-            'lang': 'all',
-            'pageno': 1,
-            'safesearch': '0',
-            'timerange': None,
-        }
-        args = ['standalone_searx', query]
-        with patch.object(sys, 'argv', args):
-            res = sas.parse_argument()
-            self.assertEqual(exp_dict, vars(res))
-        res2 = sas.parse_argument(args[1:])
-        self.assertEqual(exp_dict, vars(res2))
-
-    def test_to_dict(self):
-        """test to_dict."""
-        self.assertEqual(
-            sas.to_dict(sas.get_search_query(sas.parse_argument(['red box']))),
-            {
-                'search': {'q': 'red box', 'pageno': 1, 'lang': 'all', 'safesearch': 0, 'timerange': None},
-                'results': [],
-                'infoboxes': [],
-                'suggestions': [],
-                'answers': [],
-                'paging': False,
-                'number_of_results': 0,
-            },
-        )
-
-    def test_to_dict_with_mock(self):
-        """test to dict."""
-        with patch.object(sas.searx.search, 'Search') as mock_s:
-            m_search = mock_s().search()
-            m_sq = Mock()
-            self.assertEqual(
-                sas.to_dict(m_sq),
-                {
-                    'answers': [],
-                    'infoboxes': m_search.infoboxes,
-                    'paging': m_search.paging,
-                    'results': m_search.get_ordered_results(),
-                    'number_of_results': m_search.number_of_results,
-                    'search': {
-                        'lang': m_sq.lang,
-                        'pageno': m_sq.pageno,
-                        'q': m_sq.query,
-                        'safesearch': m_sq.safesearch,
-                        'timerange': m_sq.time_range,
-                    },
-                    'suggestions': [],
-                },
-            )
-
-    def test_get_search_query(self):
-        """test get_search_query."""
-        args = sas.parse_argument(
-            [
-                'rain',
-            ]
-        )
-        search_q = sas.get_search_query(args)
-        self.assertTrue(search_q)
-        self.assertEqual(
-            search_q, SearchQuery('rain', [EngineRef('engine1', 'general')], 'all', 0, 1, None, None, None)
-        )
-
-    def test_no_parsed_url(self):
-        """test no_parsed_url func"""
-        self.assertEqual(sas.no_parsed_url([{'parsed_url': 'http://example.com'}]), [{}])
-
-    @params((datetime.datetime(2020, 1, 1), '2020-01-01T00:00:00'), ('a'.encode('utf8'), 'a'), (set([1]), [1]))
-    def test_json_serial(self, arg, exp_res):
-        """test json_serial func"""
-        self.assertEqual(sas.json_serial(arg), exp_res)
-
-    def test_json_serial_error(self):
-        """test error on json_serial."""
-        with self.assertRaises(TypeError):
-            sas.json_serial('a')
diff --git a/tests/unit/test_webapp.py b/tests/unit/test_webapp.py
index 948b40ae..e3ca0e26 100644
--- a/tests/unit/test_webapp.py
+++ b/tests/unit/test_webapp.py
@@ -198,9 +198,7 @@ class ViewsTestCase(SearxTestCase):
         result = self.app.get('/preferences')
         self.assertEqual(result.status_code, 200)
         self.assertIn(b'<form id="search_form" method="post" action="/preferences"', result.data)
-        self.assertIn(
-            b'<input type="checkbox" id="checkbox_general" name="category_general" checked="checked"/>', result.data
-        )
+        self.assertIn(b'<div id="categories_container">', result.data)
         self.assertIn(b'<legend id="pref_ui_locale">Interface language</legend>', result.data)
 
     def test_browser_locale(self):