Improve TUN routing readability

Signed-off-by: Loren Eteval <loren.eteval@proton.me>

Furious/Frozenlib/SingTUNRouting.py

@@ -79,6 +79,7 @@ def _linuxRuleDelete(flag, rule, table, start, device):
         'dport_end',
         'dport_mask',
     }
+
     priority = int(rule['priority'])
     target = str(rule.get('table', ''))
 
@@ -345,6 +346,7 @@ class SingTUNLinuxRouting:
             ),
             [],
         )
+
         routes = sum(
             (
                 json.loads(
@@ -354,6 +356,7 @@ class SingTUNLinuxRouting:
             ),
             [],
         )
+
         tables = {str(item.get('table')) for item in rules + routes}
         priorities = {int(item['priority']) for item in rules}
 
@@ -449,6 +452,7 @@ class SingTUNLinuxRouting:
                 name = self.tun['Name']
                 index = shlex.quote('/sys/class/net/' + name + '/ifindex')
                 lines.append(f'createdIndex=$(cat {index})')
+
                 # Roll back device creation if a later setup command fails.
                 rollback = (
                     'code=$?; if [ "$code" -ne 0 ] '
@@ -479,6 +483,7 @@ class SingTUNLinuxRouting:
                 stdout=subprocess.DEVNULL,
                 stderr=subprocess.DEVNULL,
             )
+
             code = self._process.wait(timeout=self.AuthorizationTimeout)
         except subprocess.TimeoutExpired:
             # Do not drop a root process that the unprivileged owner cannot kill.
@@ -547,6 +552,7 @@ class SingTUNLinuxRouting:
             )
 
         commands.extend(self.rules)
+
         self.execute(commands, preparing=True)
 
         link = self.link()
@@ -625,6 +631,7 @@ class SingTUNLinuxRouting:
                     deletion = _linuxRuleDelete(
                         flag, rule, self.table, self.start, self.tun['Name']
                     )
+
                     if _linuxRuleSelectors(deletion) not in expected:
                         raise RuntimeError(
                             'Conflicting Linux policy rule; cleanup ownership retained'
@@ -643,6 +650,7 @@ class SingTUNLinuxRouting:
 
         for flag in ('-4', '-6'):
             rules = json.loads(_command(['ip', flag, '-N', '-j', 'rule', 'show']))
+
             routes = [
                 route
                 for route in json.loads(

Furious/Service/SingTUNHost.py

@@ -261,6 +261,7 @@ class SingTUNHostPlan:
 
             self._linux = SingTUNLinuxRouting(tun, table, start, self._cancel)
             self._activated = True
+
             self._linux.prepare()
 
             # Linux host changes belong to the helper; the spawned binding only

tests/test_connection_startup_async.py

@@ -1276,6 +1276,7 @@ class LinuxTun2socksScriptTest(TestCase):
                                     manager, attempt, None, None
                                 )
                             )
+
                             tun.stop()
                             attempt.rollback.assert_not_called()
 
@@ -1285,9 +1286,11 @@ class LinuxTun2socksScriptTest(TestCase):
 
                     if not existing:
                         self.assertIn(shlex.quote(interface), scripts[0])
+
                         bypass = next(
                             line for line in scripts[0].splitlines() if 'via ' in line
                         )
+
                         self.assertEqual(
                             shlex.split(bypass),
                             [

tests/test_sing_tun_linux_host.py

@@ -85,6 +85,7 @@ class SingTUNLinuxHostTest(unittest.TestCase):
                 Path(arguments[2]).name.startswith(tempfile.gettempprefix())
             )
             self.assertEqual(Path(arguments[2]).suffix, '.sh')
+
             scripts.append(Path(arguments[2]).read_text(encoding='utf-8'))
             return process
 
@@ -103,6 +104,7 @@ class SingTUNLinuxHostTest(unittest.TestCase):
             self.host.applyDNS('1.1.1.1')
 
         self.assertEqual(self.host.index, 77)
+
         self.assertIn('ip tuntap add dev utun101 mode tun user 1000', scripts[0])
         self.assertIn('ip link set dev utun101 mtu 1500', scripts[0])
         self.assertIn('ip -6 addr add fd00::1/64 dev utun101', scripts[0])
@@ -142,6 +144,7 @@ class SingTUNLinuxHostTest(unittest.TestCase):
                 )
 
         directory = Path(self.host._directory.name)
+
         self.assertIs(self.host._process, process)
         self.assertEqual(len(list(directory.glob('*.sh'))), 1)
         self.assertTrue((directory / 'cancelled').exists())
@@ -180,8 +183,10 @@ class SingTUNLinuxHostTest(unittest.TestCase):
                 root = Path(directory).resolve()
                 net = root / 'net'
                 binDirectory = root / 'bin'
+
                 net.mkdir()
                 binDirectory.mkdir()
+
                 ip = binDirectory / 'ip'
 
                 # This fixture only creates/removes files under its temporary
@@ -217,6 +222,7 @@ class SingTUNLinuxHostTest(unittest.TestCase):
 
                 def launch(arguments, **kwargs):
                     self.assertEqual(arguments[:2], ['pkexec', 'bash'])
+
                     script = Path(arguments[-1])
                     text = script.read_text(encoding='utf-8')
                     text = text.replace('/sys/class/net', net.as_posix())
@@ -239,6 +245,7 @@ class SingTUNLinuxHostTest(unittest.TestCase):
                         FAKE_CANCEL=(script.parent / 'cancelled').as_posix(),
                         FAKE_SCRIPT=script.as_posix(),
                     )
+
                     return realPopen([bash, str(script)], env=environment, **kwargs)
 
                 with mock.patch.object(
@@ -254,6 +261,7 @@ class SingTUNLinuxHostTest(unittest.TestCase):
                 ):
                     if failure == 'none':
                         self.host.prepare()
+
                         self.assertEqual(self.host.index, 77)
                     else:
                         with self.assertRaisesRegex(