git_command: drop custom version helper

Since ParseGitVersion can call `git --version` automatically, we don't
need this duplicate version() helper anymore.  The only other user is
the `repo version` code, so convert that to version_tuple().full.

Bug: https://crbug.com/gerrit/11144
Change-Id: I9d77822fc39f4ba28884d9183359169cabf5f17d
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/231055
Reviewed-by: David Pursehouse <dpursehouse@collab.net>
Tested-by: Mike Frysinger <vapier@google.com>

git_command.py

@@ -80,22 +80,12 @@ def terminate_ssh_clients():
 _git_version = None
 
 class _GitCall(object):
-  def version(self):
-    p = GitCommand(None, ['--version'], capture_stdout=True)
-    if p.Wait() == 0:
-      if hasattr(p.stdout, 'decode'):
-        return p.stdout.decode('utf-8')
-      else:
-        return p.stdout
-    return None
-
   def version_tuple(self):
     global _git_version
     if _git_version is None:
-      ver_str = git.version()
-      _git_version = Wrapper().ParseGitVersion(ver_str)
+      _git_version = Wrapper().ParseGitVersion()
       if _git_version is None:
-        print('fatal: "%s" unsupported' % ver_str, file=sys.stderr)
+        print('fatal: unable to detect git version', file=sys.stderr)
         sys.exit(1)
     return _git_version
 

subcmds/version.py

@@ -41,5 +41,5 @@ class Version(Command, MirrorSafeCommand):
       print('repo launcher version %s' % Version.wrapper_version)
       print('       (from %s)' % Version.wrapper_path)
 
-    print(git.version().strip())
+    print('git %s' % git.version_tuple().full)
     print('Python %s' % sys.version)

tests/test_git_command.py

@@ -0,0 +1,45 @@
+# -*- coding:utf-8 -*-
+#
+# Copyright 2019 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+
+import git_command
+
+
+class GitCallUnitTest(unittest.TestCase):
+  """Tests the _GitCall class (via git_command.git)."""
+
+  def test_version_tuple(self):
+    """Check git.version_tuple() handling."""
+    ver = git_command.git.version_tuple()
+    self.assertIsNotNone(ver)
+
+    # We don't dive too deep into the values here to avoid having to update
+    # whenever git versions change.  We do check relative to this min version
+    # as this is what `repo` itself requires via MIN_GIT_VERSION.
+    MIN_GIT_VERSION = (1, 7, 2)
+    self.assertTrue(isinstance(ver.major, int))
+    self.assertTrue(isinstance(ver.minor, int))
+    self.assertTrue(isinstance(ver.micro, int))
+
+    self.assertGreater(ver.major, MIN_GIT_VERSION[0] - 1)
+    self.assertGreaterEqual(ver.micro, 0)
+    self.assertGreaterEqual(ver.major, 0)
+
+    self.assertGreaterEqual(ver, MIN_GIT_VERSION)
+    self.assertLess(ver, (9999, 9999, 9999))
+
+    self.assertNotEqual('', ver.full)