diff --git a/tests/test_functions.py b/tests/test_functions.py
index 4c503e5..2cea0f8 100644
--- a/tests/test_functions.py
+++ b/tests/test_functions.py
@@ -66,8 +66,9 @@ class FunctionsTestCase(IsolatedAsyncioTestCase):
         with self.assertRaises(UnknownFinancialStatementItem):
             functions.is_relevant_table_row(test_soup.tr)
 
+    @patch.object(functions, 'open')
     @patch.object(functions, 'is_relevant_table_row')
-    def test_find_relevant_table_rows(self, mock_is_relevant_table_row):
+    def test_find_relevant_table_rows(self, mock_is_relevant_table_row, mock_open):
         mock_is_relevant_table_row.return_value = True
         expected_output = self.test_soup.find('div', attrs={'class': 'financials'}).tbody.find_all('tr')
         tr0, tr1 = expected_output
@@ -81,6 +82,14 @@ class FunctionsTestCase(IsolatedAsyncioTestCase):
         output = functions.find_relevant_table_rows(self.test_soup)
         self.assertListEqual(expected_output, output)
         mock_is_relevant_table_row.assert_has_calls([call(tr0), call(tr1)])
+        mock_is_relevant_table_row.reset_mock()
+
+        mock_write = mock_open.return_value.__enter__.return_value.write
+        with patch.object(functions, 'DEV_MODE', new=True):
+            output = functions.find_relevant_table_rows(self.test_soup)
+        self.assertListEqual(expected_output, output)
+        mock_is_relevant_table_row.assert_has_calls([call(tr0), call(tr1)])
+        mock_write.assert_has_calls([call(str(self.test_soup)), call(str(self.test_soup))])
 
     def test_extract_row_data(self):
         test_row = self.test_soup.find('div', attrs={'class': 'financials'}).tbody.tr