git cl issue: add --json switch for machine-readable output

tests/git_cl_test.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Unit tests for git_cl.py."""
 
 import os
 import StringIO
 import stat
@@ skipping 233 matching lines @@
     self.mock(subprocess2, 'communicate',
               lambda *a, **kw: ([self._mocked_call(*a, **kw), ''], 0))
     self.mock(git_cl.gclient_utils, 'CheckCallAndFilter', self._mocked_call)
     self.mock(git_common, 'is_dirty_git_tree', lambda x: False)
     self.mock(git_common, 'get_or_create_merge_base',
               lambda *a: (
                   self._mocked_call(['get_or_create_merge_base']+list(a))))
     self.mock(git_cl, 'BranchExists', lambda _: True)
     self.mock(git_cl, 'FindCodereviewSettingsFile', lambda: '')
     self.mock(git_cl, 'ask_for_data', self._mocked_call)
+    self.mock(git_cl, 'write_json', lambda path, contents:
+        self._mocked_call('write_json', path, contents))
     self.mock(git_cl.presubmit_support, 'DoPresubmitChecks', PresubmitMock)
     self.mock(git_cl.rietveld, 'Rietveld', RietveldMock)
     self.mock(git_cl.rietveld, 'CachingRietveld', RietveldMock)
     self.mock(git_cl.upload, 'RealMain', self.fail)
     self.mock(git_cl.watchlists, 'Watchlists', WatchlistsMock)
     self.mock(git_cl.auth, 'get_authenticator_for_host', AuthenticatorMock)
     self.mock(git_cl.gerrit_util.GceAuthenticator, 'is_gce',
               classmethod(lambda _: False))
     # It's important to reset settings to not have inter-tests interference.
     git_cl.settings = None
@@ skipping 1488 matching lines @@
         ((['git', 'config', '--unset', 'branch.feature.last-upload-hash'],),
          CERR1),
         ((['git', 'config', '--unset', 'branch.feature.gerritissue'],), ''),
         ((['git', 'config', '--unset', 'branch.feature.gerritpatchset'],), ''),
         ((['git', 'config', '--unset', 'branch.feature.gerritserver'],), ''),
         ((['git', 'config', '--unset', 'branch.feature.gerritsquashhash'],),
          ''),
     ]
     self.assertEqual(0, git_cl.main(['issue', '0']))
 
+  def test_cmd_issue_json(self):
+    out = StringIO.StringIO()
+    self.mock(git_cl.sys, 'stdout', out)
+    self.calls = [
+        ((['git', 'symbolic-ref', 'HEAD'],), 'feature'),
+        ((['git', 'config', '--int', 'branch.feature.rietveldissue'],), '123'),
+        ((['git', 'config', 'rietveld.autoupdate'],), ''),
+        ((['git', 'config', 'rietveld.server'],),
+         'https://codereview.chromium.org'),
+        ((['git', 'config', 'branch.feature.rietveldserver'],), ''),
+        (('write_json', 'output.json',
+          {'issue': 123, 'issue_url': 'https://codereview.chromium.org/123'}),
+         ''),
+    ]
+    self.assertEqual(0, git_cl.main(['issue', '--json', 'output.json']))
+
   def test_git_cl_try_default(self):
     self.mock(git_cl.Changelist, 'GetChange',
               lambda _, *a: (
                 self._mocked_call(['GetChange']+list(a))))
     self.mock(git_cl.presubmit_support, 'DoGetTryMasters',
               lambda *_, **__: (
                 self._mocked_call(['DoGetTryMasters'])))
     self.mock(git_cl.presubmit_support, 'DoGetTrySlaves',
               lambda *_, **__: (
                 self._mocked_call(['DoGetTrySlaves'])))
@@ skipping 67 matching lines @@
         ((['rm_file_or_tree', '/abs/git_repo_root/.git/hooks/commit-msg'],),
          ''),
     ]
     cl._codereview_impl._GerritCommitMsgHookCheck(offer_removal=True)
 
 
 if __name__ == '__main__':
   git_cl.logging.basicConfig(
       level=git_cl.logging.DEBUG if '-v' in sys.argv else git_cl.logging.ERROR)
   unittest.main()