From 7dbfcf568be02408d299e7c17ca4e22569af0f4d Mon Sep 17 00:00:00 2001
From: Daniil Fajnberg <mail@daniil.fajnberg.de>
Date: Mon, 15 Nov 2021 16:06:58 +0100
Subject: [PATCH] comments and minor refactoring

---
 tests/test_scrape.py | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/tests/test_scrape.py b/tests/test_scrape.py
index 8f74b21..05d1c8f 100644
--- a/tests/test_scrape.py
+++ b/tests/test_scrape.py
@@ -94,47 +94,53 @@ class ScrapeTestCase(IsolatedAsyncioTestCase):
     @patch.object(scrape, 'ClientSession')
     async def test_get_data_from_category(self, mock_session_cls, mock_extract_row_data,
                                           mock_trs_from_page, mock_soup_from_url):
+        # We do not pass a session object into the tested function,
+        # so we mock the ClientSession class for the first two tests.
         mock_session = MagicMock()
         mock_session_cls.return_value = mock_session
         mock_soup = MagicMock()
         mock_soup_from_url.return_value = mock_soup
         category = 'ßßß'
+        url = f'{scrape.BASE_URL}{category}'
 
+        # First test with no TRs returned, thus not entering the loop.
         mock_trs = []
         mock_trs_from_page.return_value = mock_trs
         mock_extract_row_data.return_value = expected_output = []
-        output = await scrape.get_data_from_category(category, last_page=1)
+        output = await scrape.get_data_from_category(category)
         self.assertListEqual(expected_output, output)
-        mock_soup_from_url.assert_called_once_with(f'{scrape.BASE_URL}{category}', mock_session)
+        mock_soup_from_url.assert_called_once_with(url, mock_session)
         mock_trs_from_page.assert_called_once_with(mock_soup)
         mock_extract_row_data.assert_not_called()
+
         mock_soup_from_url.reset_mock()
         mock_trs_from_page.reset_mock()
 
+        # Second test with (fake) TRs returned, thus entering the loop.
+        # We pass a last_page argument to stop after the first iteration.
         mock_trs = ['foo', 'bar']
         mock_trs_from_page.return_value = mock_trs
         mock_extract_row_data.return_value = expected_output = ['a', 'b']
+
+        # Factored out checks because the only difference in the next two tests is the presence or absence of a
+        # real session instance.
+        def check_assertions(test_output, session_obj):
+            self.assertListEqual(expected_output, test_output)
+            mock_soup_from_url.assert_has_calls([call(url, session_obj), call(f'{url}/{2}', session_obj)])
+            mock_trs_from_page.assert_has_calls([call(mock_soup), call(mock_soup)])
+            mock_extract_row_data.assert_called_once_with(*mock_trs)
+
         output = await scrape.get_data_from_category(category, last_page=1)
-        self.assertListEqual(expected_output, output)
-        mock_soup_from_url.assert_has_calls([
-            call(f'{scrape.BASE_URL}{category}', mock_session),
-            call(f'{scrape.BASE_URL}{category}/{2}', mock_session)
-        ])
-        mock_trs_from_page.assert_has_calls([call(mock_soup), call(mock_soup)])
-        mock_extract_row_data.assert_called_once_with(*mock_trs)
+        check_assertions(output, mock_session)
+
         mock_soup_from_url.reset_mock()
         mock_trs_from_page.reset_mock()
         mock_extract_row_data.reset_mock()
 
+        # Third test with (fake) TRs returned and explicitly passing a real session object.
         async with scrape.ClientSession() as session:
             output = await scrape.get_data_from_category(category, session, last_page=1)
-            self.assertListEqual(expected_output, output)
-            mock_soup_from_url.assert_has_calls([
-                call(f'{scrape.BASE_URL}{category}', session),
-                call(f'{scrape.BASE_URL}{category}/{2}', session)
-            ])
-            mock_trs_from_page.assert_has_calls([call(mock_soup), call(mock_soup)])
-            mock_extract_row_data.assert_called_once_with(*mock_trs)
+            check_assertions(output, session)
 
     @patch.object(scrape, 'get_data_from_category')
     @patch.object(scrape, 'ClientSession')
@@ -144,11 +150,13 @@ class ScrapeTestCase(IsolatedAsyncioTestCase):
         mock_result = ['foo']
         expected_output = len(scrape.CATEGORIES) * mock_result
         mock_get_data_from_category.return_value = mock_result
+
         output = await scrape.get_all_data(sequential=True)
         self.assertListEqual(expected_output, output)
         mock_get_data_from_category.assert_has_calls([
             call(category, mock_session) for category in scrape.CATEGORIES
         ])
+
         output = await scrape.get_all_data(sequential=False)
         self.assertListEqual(expected_output, output)
         mock_get_data_from_category.assert_has_calls([