Run presubmit checks without GerritAccessor if GERRIT_HOST is not set.

When a repository doesn't work with Gerrit, it doesn't make sense to
create GerritAccessor and pass it to presubmit checks.
gerrit.host is stored into git config when codereview.settings file contains GERRIT_HOST item.

Change-Id: I9740950caf85a1da9a6e4ae12e3612625cf0cec5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3687235Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Auto-Submit: Aleksey Khoroshilov <akhoroshilov@brave.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

git_cl.py

@@ -805,6 +805,12 @@ class Settings(object):
       return False
     return None
 
+  def GetIsGerrit(self):
+    """Return True if gerrit.host is set."""
+    if self.is_gerrit is None:
+      self.is_gerrit = bool(self._GetConfig('gerrit.host', False))
+    return self.is_gerrit
+
   def GetGerritSkipEnsureAuthenticated(self):
     """Return True if EnsureAuthenticated should not be done for Gerrit
     uploads."""
@@ -1323,9 +1329,10 @@ class Changelist(object):
 
     remote, remote_branch = self.GetRemoteBranch()
     target_ref = GetTargetRef(remote, remote_branch, None)
-    args.extend(['--gerrit_url', self.GetCodereviewServer()])
-    args.extend(['--gerrit_project', self.GetGerritProject()])
-    args.extend(['--gerrit_branch', target_ref])
+    if settings.GetIsGerrit():
+      args.extend(['--gerrit_url', self.GetCodereviewServer()])
+      args.extend(['--gerrit_project', self.GetGerritProject()])
+      args.extend(['--gerrit_branch', target_ref])
 
     author = self.GetAuthor()
     issue = self.GetIssue()

tests/git_cl_test.py

@@ -3061,6 +3061,7 @@ class ChangelistTest(unittest.TestCase):
         return_value=('origin', 'refs/remotes/origin/main')).start()
     mock.patch('git_cl.PRESUBMIT_SUPPORT', 'PRESUBMIT_SUPPORT').start()
     mock.patch('git_cl.Settings.GetRoot', return_value='root').start()
+    mock.patch('git_cl.Settings.GetIsGerrit', return_value=True).start()
     mock.patch('git_cl.time_time').start()
     mock.patch('metrics.collector').start()
     mock.patch('subprocess2.Popen').start()
@@ -3231,6 +3232,53 @@ class ChangelistTest(unittest.TestCase):
         '--description_file', '/tmp/fake-temp1',
     ])
 
+  def testRunHook_NoGerrit(self):
+    mock.patch('git_cl.Settings.GetIsGerrit', return_value=False).start()
+
+    expected_results = {
+        'more_cc': ['cc@example.com', 'more@example.com'],
+        'errors': [],
+        'notifications': [],
+        'warnings': [],
+    }
+    gclient_utils.FileRead.return_value = json.dumps(expected_results)
+    git_cl.time_time.side_effect = [100, 200, 300, 400]
+    mockProcess = mock.Mock()
+    mockProcess.wait.return_value = 0
+    subprocess2.Popen.return_value = mockProcess
+
+    git_cl.Changelist.GetAuthor.return_value = None
+    git_cl.Changelist.GetIssue.return_value = None
+    git_cl.Changelist.GetPatchset.return_value = None
+
+    cl = git_cl.Changelist()
+    results = cl.RunHook(
+        committing=False,
+        may_prompt=False,
+        verbose=0,
+        parallel=False,
+        upstream='upstream',
+        description='description',
+        all_files=False,
+        resultdb=False)
+
+    self.assertEqual(expected_results, results)
+    subprocess2.Popen.assert_any_call([
+        'vpython3', 'PRESUBMIT_SUPPORT',
+        '--root', 'root',
+        '--upstream', 'upstream',
+        '--upload',
+        '--json_output', '/tmp/fake-temp2',
+        '--description_file', '/tmp/fake-temp1',
+    ])
+    gclient_utils.FileWrite.assert_any_call(
+        '/tmp/fake-temp1', 'description')
+    metrics.collector.add_repeated('sub_commands', {
+      'command': 'presubmit',
+      'execution_time': 100,
+      'exit_code': 0,
+    })
+
   @mock.patch('sys.exit', side_effect=SystemExitMock)
   def testRunHook_Failure(self, _mock):
     git_cl.time_time.side_effect = [100, 200]