git cl comment: implement adding comment for Gerrit.

BUG=698236

Change-Id: Ia1a36af71c348be991d77083092c5043c2642c19
Reviewed-on: https://chromium-review.googlesource.com/455877Reviewed-by: Aaron Gable <agable@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>

git_cl.py

@@ -1654,6 +1654,9 @@ class Changelist(object):
 
   # Forward methods to codereview specific implementation.
 
+  def AddComment(self, message):
+    return self._codereview_impl.AddComment(message)
+
   def CloseIssue(self):
     return self._codereview_impl.CloseIssue()
 
@@ -1752,6 +1755,10 @@ class _ChangelistCodereviewBase(object):
     """Update the description on codereview site."""
     raise NotImplementedError()
 
+  def AddComment(self, message):
+    """Posts a comment to the codereview site."""
+    raise NotImplementedError()
+
   def CloseIssue(self):
     """Closes the issue."""
     raise NotImplementedError()
@@ -2488,6 +2495,10 @@ class _GerritChangelistImpl(_ChangelistCodereviewBase):
     gerrit_util.SetCommitMessage(self._GetGerritHost(), self.GetIssue(),
                                  description, notify='NONE')
 
+  def AddComment(self, message):
+    gerrit_util.SetReview(self._GetGerritHost(), self.GetIssue(),
+                          msg=message)
+
   def CloseIssue(self):
     gerrit_util.AbandonChange(self._GetGerritHost(), self.GetIssue(), msg='')
 
@@ -4198,11 +4209,13 @@ def CMDcomments(parser, args):
   parser.add_option('-a', '--add-comment', dest='comment',
                     help='comment to add to an issue')
   parser.add_option('-i', dest='issue',
-                    help="review issue id (defaults to current issue)")
+                    help='review issue id (defaults to current issue)')
   parser.add_option('-j', '--json-file',
                     help='File to write JSON summary to')
   auth.add_auth_options(parser)
+  _add_codereview_select_options(parser)
   options, args = parser.parse_args(args)
+  _process_codereview_select_options(parser, options)
   auth_config = auth.extract_auth_config_from_options(options)
 
   issue = None
@@ -4212,7 +4225,10 @@ def CMDcomments(parser, args):
     except ValueError:
       DieWithError('A review issue id is expected to be a number')
 
-  cl = Changelist(issue=issue, codereview='rietveld', auth_config=auth_config)
+  cl = Changelist(issue=issue,
+                  # TODO(tandrii): remove 'rietveld' default.
+                  codereview=options.forced_codereview or 'rietveld',
+                  auth_config=auth_config)
 
   if options.comment:
     cl.AddComment(options.comment)

tests/git_cl_test.py

@@ -3089,6 +3089,34 @@ class TestGitCl(TestCase):
         sys.stdout.getvalue(),
         'However, your configured .gitcookies file is missing.')
 
+  def test_git_cl_comment_add_default(self):
+    self.mock(git_cl._RietveldChangelistImpl, 'AddComment',
+              lambda _, message: self._mocked_call('AddComment', message))
+    self.calls = [
+      ((['git', 'config', 'rietveld.autoupdate'],), CERR1),
+      ((['git', 'config', 'rietveld.server'],), 'codereview.chromium.org'),
+      (('AddComment', 'msg'), ''),
+    ]
+    # TODO(tandrii): --rietveld should be specified here.
+    self.assertEqual(0, git_cl.main(['comment', '-i', '10', '-a', 'msg']))
+
+  def test_git_cl_comment_add_gerrit(self):
+    self.mock(git_cl.gerrit_util, 'SetReview',
+              lambda host, change, msg:
+              self._mocked_call('SetReview', host, change, msg))
+    self.calls = [
+      ((['git', 'symbolic-ref', 'HEAD'],), CERR1),
+      ((['git', 'symbolic-ref', 'HEAD'],), CERR1),
+      ((['git', 'config', 'rietveld.upstream-branch'],), CERR1),
+      ((['git', 'branch', '-r'],), 'origin/HEAD -> origin/master\n'
+                                   'origin/master'),
+      ((['git', 'config', 'remote.origin.url'],),
+       'https://chromium.googlesource.com/infra/infra'),
+      (('SetReview', 'chromium-review.googlesource.com', 10, 'msg'), None),
+    ]
+    self.assertEqual(0, git_cl.main(['comment', '--gerrit', '-i', '10',
+                                     '-a', 'msg']))
+
 
 if __name__ == '__main__':
   logging.basicConfig(