repo: add --version support to the launcher

We can get version info when in a checkout, but it'd be helpful
to show that info at all times.

Change-Id: Ieeb44a503c9d7d8c487db4810bdcf3d5f6656c82
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/254712
Reviewed-by: Michael Mortensen <mmortensen@google.com>
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: Mike Frysinger <vapier@google.com>

repo

@@ -819,6 +819,7 @@ def _FindRepo():
 
 class _Options(object):
   help = False
+  version = False
 
 
 def _ParseArguments(args):
@@ -830,7 +831,8 @@ def _ParseArguments(args):
     a = args[i]
     if a == '-h' or a == '--help':
       opt.help = True
-
+    elif a == '--version':
+      opt.version = True
     elif not a.startswith('-'):
       cmd = a
       arg = args[i + 1:]
@@ -877,6 +879,16 @@ def _Help(args):
   sys.exit(1)
 
 
+def _Version():
+  """Show version information."""
+  print('<repo not installed>')
+  print('repo launcher version %s' % ('.'.join(str(x) for x in VERSION),))
+  print('       (from %s)' % (__file__,))
+  print('git %s' % (ParseGitVersion().full,))
+  print('Python %s' % sys.version)
+  sys.exit(0)
+
+
 def _NotInstalled():
   print('error: repo is not installed.  Use "repo init" to install it here.',
         file=sys.stderr)
@@ -953,6 +965,8 @@ def main(orig_args):
       _Usage()
     if cmd == 'help':
       _Help(args)
+    if opt.version or cmd == 'version':
+      _Version()
     if not cmd:
       _NotInstalled()
     if cmd == 'init' or cmd == 'gitc-init':

tests/test_wrapper.py

@@ -26,6 +26,14 @@ from pyversion import is_python3
 import wrapper
 
 
+if is_python3():
+  from unittest import mock
+  from io import StringIO
+else:
+  import mock
+  from StringIO import StringIO
+
+
 def fixture(*paths):
   """Return a path relative to tests/fixtures.
   """
@@ -48,6 +56,16 @@ class RepoWrapperUnitTest(RepoWrapperTestCase):
   """Tests helper functions in the repo wrapper
   """
 
+  def test_version(self):
+    """Make sure _Version works."""
+    with self.assertRaises(SystemExit) as e:
+      with mock.patch('sys.stdout', new_callable=StringIO) as stdout:
+        with mock.patch('sys.stderr', new_callable=StringIO) as stderr:
+          self.wrapper._Version()
+    self.assertEqual(0, e.exception.code)
+    self.assertEqual('', stderr.getvalue())
+    self.assertIn('repo launcher version', stdout.getvalue())
+
   def test_get_gitc_manifest_dir_no_gitc(self):
     """
     Test reading a missing gitc config file

tox.ini

@@ -20,3 +20,8 @@ envlist = py27, py36, py37, py38
 [testenv]
 deps = pytest
 commands = {toxinidir}/run_tests
+
+[testenv:py27]
+deps =
+    mock
+    pytest