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

This was requested in https://chromium-review.googlesource.com/c/373499

BUG=none

Review-Url: https://codereview.chromium.org/2263103002

git_cl.py

@@ -3446,6 +3446,11 @@ def colorize_CMDstatus_doc():
   CMDstatus.__doc__ = '\n'.join(colorize_line(l) for l in lines)
 
 
+def write_json(path, contents):
+  with open(path, 'w') as f:
+    json.dump(contents, f)
+
+
 @subcommand.usage('[issue_number]')
 def CMDissue(parser, args):
   """Sets or displays the current code review issue number.
@@ -3456,6 +3461,7 @@ def CMDissue(parser, args):
                     help='Lookup the branch(es) for the specified issues. If '
                          'no issues are specified, all branches with mapped '
                          'issues will be listed.')
+  parser.add_option('--json', help='Path to JSON output file.')
   _add_codereview_select_options(parser)
   options, args = parser.parse_args(args)
   _process_codereview_select_options(parser, options)
@@ -3471,11 +3477,15 @@ def CMDissue(parser, args):
       issue_branch_map.setdefault(cl.GetIssue(), []).append(branch)
     if not args:
       args = sorted(issue_branch_map.iterkeys())
+    result = {}
     for issue in args:
       if not issue:
         continue
+      result[int(issue)] = issue_branch_map.get(int(issue))
       print('Branch for issue number %s: %s' % (
           issue, ', '.join(issue_branch_map.get(int(issue)) or ('None',))))
+    if options.json:
+      write_json(options.json, result)
   else:
     cl = Changelist(codereview=options.forced_codereview)
     if len(args) > 0:
@@ -3486,6 +3496,11 @@ def CMDissue(parser, args):
                      'Maybe you want to run git cl status?')
       cl.SetIssue(issue)
     print('Issue number: %s (%s)' % (cl.GetIssue(), cl.GetIssueURL()))
+    if options.json:
+      write_json(options.json, {
+        'issue': cl.GetIssue(),
+        'issue_url': cl.GetIssueURL(),
+      })
   return 0
 
 

tests/git_cl_test.py

@@ -251,6 +251,8 @@ class TestGitCl(TestCase):
     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)
@@ -1759,6 +1761,22 @@ class TestGitCl(TestCase):
     ]
     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: (