[refactor] typification of SearXNG / EngineResults

In [1] and [2] we discussed the need of a Result.results property and how we can
avoid unclear code.  This patch implements a class for the reslut-lists of
engines::

    searx.result_types.EngineResults

A simple example for the usage in engine development::

    from searx.result_types import EngineResults
    ...
    def response(resp) -> EngineResults:
        res = EngineResults()
        ...
        res.add( res.types.Answer(answer="lorem ipsum ..", url="https://example.org") )
        ...
        return res

[1] https://github.com/searxng/searxng/pull/4183#pullrequestreview-257400034
[2] https://github.com/searxng/searxng/pull/4183#issuecomment-2614301580
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

tests/unit/engines/test_xpath.py

@@ -70,7 +70,7 @@ class TestXpathEngine(SearxTestCase):
 
         response = mock.Mock(text=self.html, status_code=200)
         results = xpath.response(response)
-        self.assertEqual(type(results), list)
+        self.assertIsInstance(results, list)
         self.assertEqual(len(results), 2)
         self.assertEqual(results[0]['title'], 'Result 1')
         self.assertEqual(results[0]['url'], 'https://result1.com/')
@@ -82,7 +82,7 @@ class TestXpathEngine(SearxTestCase):
         # with cached urls, without results_xpath
         xpath.cached_xpath = '//div[@class="search_result"]//a[@class="cached"]/@href'
         results = xpath.response(response)
-        self.assertEqual(type(results), list)
+        self.assertIsInstance(results, list)
         self.assertEqual(len(results), 2)
         self.assertEqual(results[0]['cached_url'], 'https://cachedresult1.com')
         self.assertEqual(results[1]['cached_url'], 'https://cachedresult2.com')
@@ -112,7 +112,7 @@ class TestXpathEngine(SearxTestCase):
 
         response = mock.Mock(text=self.html, status_code=200)
         results = xpath.response(response)
-        self.assertEqual(type(results), list)
+        self.assertIsInstance(results, list)
         self.assertEqual(len(results), 2)
         self.assertEqual(results[0]['title'], 'Result 1')
         self.assertEqual(results[0]['url'], 'https://result1.com/')
@@ -124,7 +124,7 @@ class TestXpathEngine(SearxTestCase):
         # with cached urls, with results_xpath
         xpath.cached_xpath = './/a[@class="cached"]/@href'
         results = xpath.response(response)
-        self.assertEqual(type(results), list)
+        self.assertIsInstance(results, list)
         self.assertEqual(len(results), 2)
         self.assertEqual(results[0]['cached_url'], 'https://cachedresult1.com')
         self.assertEqual(results[1]['cached_url'], 'https://cachedresult2.com')

tests/unit/test_plugin_calculator.py

@@ -38,7 +38,7 @@ class PluginCalculator(SearxTestCase):
         with self.app.test_request_context():
             sxng_request.preferences = self.pref
             query = "1+1"
-            answer = Answer(results=[], answer=f"{query} = {eval(query)}")  # pylint: disable=eval-used
+            answer = Answer(answer=f"{query} = {eval(query)}")  # pylint: disable=eval-used
 
             search = do_post_search(query, self.storage, pageno=1)
             self.assertIn(answer, search.result_container.answers)
@@ -81,7 +81,7 @@ class PluginCalculator(SearxTestCase):
         with self.app.test_request_context():
             self.pref.parse_dict({"locale": lang})
             sxng_request.preferences = self.pref
-            answer = Answer(results=[], answer=f"{query} = {res}")
+            answer = Answer(answer=f"{query} = {res}")
 
             search = do_post_search(query, self.storage)
             self.assertIn(answer, search.result_container.answers)

tests/unit/test_plugin_hash.py

@@ -51,7 +51,7 @@ class PluginHashTest(SearxTestCase):
     def test_hash_digest_new(self, query: str, res: str):
         with self.app.test_request_context():
             sxng_request.preferences = self.pref
-            answer = Answer(results=[], answer=res)
+            answer = Answer(answer=res)
 
             search = do_post_search(query, self.storage)
             self.assertIn(answer, search.result_container.answers)
@@ -60,7 +60,7 @@ class PluginHashTest(SearxTestCase):
         with self.app.test_request_context():
             sxng_request.preferences = self.pref
             query, res = query_res[0]
-            answer = Answer(results=[], answer=res)
+            answer = Answer(answer=res)
 
             search = do_post_search(query, self.storage, pageno=1)
             self.assertIn(answer, search.result_container.answers)

tests/unit/test_plugin_self_info.py

@@ -39,7 +39,7 @@ class PluginIPSelfInfo(SearxTestCase):
             sxng_request.preferences = self.pref
             sxng_request.remote_addr = "127.0.0.1"
             sxng_request.headers = {"X-Forwarded-For": "1.2.3.4, 127.0.0.1", "X-Real-IP": "127.0.0.1"}  # type: ignore
-            answer = Answer(results=[], answer=gettext("Your IP is: ") + "127.0.0.1")
+            answer = Answer(answer=gettext("Your IP is: ") + "127.0.0.1")
 
             search = do_post_search("ip", self.storage, pageno=1)
             self.assertIn(answer, search.result_container.answers)
@@ -60,7 +60,7 @@ class PluginIPSelfInfo(SearxTestCase):
         with self.app.test_request_context():
             sxng_request.preferences = self.pref
             sxng_request.user_agent = "Dummy agent"  # type: ignore
-            answer = Answer(results=[], answer=gettext("Your user-agent is: ") + "Dummy agent")
+            answer = Answer(answer=gettext("Your user-agent is: ") + "Dummy agent")
 
             search = do_post_search(query, self.storage, pageno=1)
             self.assertIn(answer, search.result_container.answers)

tests/unit/test_plugins.py

@@ -101,6 +101,6 @@ class PluginStorage(SearxTestCase):
             ret = self.storage.on_result(
                 sxng_request,
                 get_search_mock("lorem ipsum", user_plugins=["plg001", "plg002"]),
-                Result(results=[]),
+                Result(),
             )
             self.assertFalse(ret)