Fix tests

tests/model/reftek_data/test_reftek.py

+from datetime import datetime
 from unittest import TestCase
 from pathlib import Path
+from unittest.mock import patch
 
+from sohstationviewer.conf.constants import SOFTWARE_VERSION
 from sohstationviewer.model.reftek_data.reftek import RT130
 from sohstationviewer.model.general_data.general_data import \
     ProcessingDataError
@@ -12,6 +15,19 @@ reftek_data = TEST_DATA_DIR.joinpath("RT130-sample")
 reftek_gap_data = TEST_DATA_DIR.joinpath("RT130-gap")
 
 
+# noinspection PyMissingOrEmptyDocstring
+class Mock_datetime(datetime): # noqa: N801
+    @classmethod
+    def now(cls, tz=None) -> datetime:
+        """
+        Mock datetime.now to return a static datetime object.
+        :return: a static datetime object
+        """
+        # The formatting method we used does not take millisecond into
+        # account, so we can omit it.
+        return datetime(2023, 10, 5, 15, 8, 5)
+
+
 class TestReftek(TestCase):
     def test_path_not_exist(self):
         # raise exception when path not exist
@@ -28,6 +44,7 @@ class TestReftek(TestCase):
                 "Path '_' not exist"
             )
 
+    @patch('datetime.datetime', Mock_datetime)
     def test_read_soh(self):
         args = {
             'data_type': 'RT130',
@@ -50,11 +67,12 @@ class TestReftek(TestCase):
         self.assertEqual(len(obj.log_data['TEXT']), 0)
         self.assertEqual(list(obj.log_data[('92EB', '25')].keys()), ['SOH'])
         self.assertEqual(len(obj.log_data[('92EB', '25')]['SOH']), 1)
+        formatted_time = 'Thu Oct  5 15:08:05 2023'
         self.assertEqual(
             obj.log_data[('92EB', '25')]['SOH'][0][:100],
-            '\nState of Health  17:150:00:00:00:000   ST: 92EB'
-            '\n150:00:00:00 REF TEK 130'
-            '\r\n150:00:00:00 CPU SOFTWARE')
+            f'SOHStationViewer: v{SOFTWARE_VERSION} '
+            f'Run time (UTC): {formatted_time}'
+            '\n\nState of Health  17:150:00:0')
         self.assertEqual(list(obj.soh_data.keys()), [('92EB', '25')])
         self.assertEqual(sorted(list(obj.soh_data[('92EB', '25')].keys())),
                          sorted(expected_soh))
@@ -149,6 +167,7 @@ class TestReftek(TestCase):
             self.assertEqual(obj.gaps[('98AD', '0')],
                              [[1648493999.64, 1648508400.64]])
 
+    @patch('datetime.datetime', Mock_datetime)
     def test_select_2_folders(self):
         args = {
             'data_type': 'RT130',
@@ -176,11 +195,12 @@ class TestReftek(TestCase):
         self.assertEqual(len(obj.log_data['TEXT']), 0)
         self.assertEqual(list(obj.log_data[('92EB', '25')].keys()), ['SOH'])
         self.assertEqual(len(obj.log_data[('92EB', '25')]['SOH']), 1)
+        formatted_time = 'Thu Oct  5 15:08:05 2023'
         self.assertEqual(
             obj.log_data[('92EB', '25')]['SOH'][0][:100],
-            '\nState of Health  17:150:00:00:00:000   ST: 92EB'
-            '\n150:00:00:00 REF TEK 130'
-            '\r\n150:00:00:00 CPU SOFTWARE')
+            f'SOHStationViewer: v{SOFTWARE_VERSION} '
+            f'Run time (UTC): {formatted_time}'
+            '\n\nState of Health  17:150:00:0')
         self.assertEqual(list(obj.soh_data.keys()),
                          [('92EB', '25'), ('98AD', '0')])
         self.assertEqual(sorted(list(obj.soh_data[('92EB', '25')].keys())),