Add a basic depot_tools version information

depot_tools has no versioning. It's hard to know if reported issues were
caused due to outdated depot_tools or actual unresolved bug.

This CL adds basic information about depot_tools version and it's
included in presubmit failure.

R=aravindvasudev@google.com, gavinmak@google.com

Change-Id: If8577c0826063693a7278a57a0cce629d4b1325f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3541061
Reviewed-by: Aravind Vasudevan <aravindvasudev@google.com>
Reviewed-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

git_cl.py

@@ -5471,6 +5471,11 @@ def CMDlol(parser, args):
   return 0
 
 
+def CMDversion(parser, args):
+  import utils
+  print(utils.depot_tools_version())
+
+
 class OptionParser(optparse.OptionParser):
   """Creates the option parse and add --verbose support."""
 

presubmit_support.py

@@ -1988,8 +1988,11 @@ def main(argv=None):
           options.json_output,
           options.use_python3)
   except PresubmitFailure as e:
+    import utils
     print(e, file=sys.stderr)
     print('Maybe your depot_tools is out of date?', file=sys.stderr)
+    print('depot_tools version: %s' % utils.depot_tools_version(),
+          file=sys.stderr)
     return 2
 
 

tests/utils_test.py

@@ -0,0 +1,54 @@
+#!/usr/bin/env vpython3
+# Copyright 2022 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.
+
+import logging
+import os
+import sys
+import unittest
+
+if sys.version_info.major == 2:
+  import mock
+else:
+  from unittest import mock
+
+DEPOT_TOOLS_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, DEPOT_TOOLS_ROOT)
+
+from testing_support import coverage_utils
+import utils
+
+
+class GitCacheTest(unittest.TestCase):
+  def setUp(self):
+    pass
+
+  @mock.patch('subprocess.check_output', lambda x, **kwargs: b'foo')
+  def testVersionWithGit(self):
+    version = utils.depot_tools_version()
+    self.assertEqual(version, 'git-foo')
+
+  @mock.patch('subprocess.check_output')
+  @mock.patch('os.path.getmtime', lambda x: 42)
+  def testVersionWithNoGit(self, mock_subprocess):
+    mock_subprocess.side_effect = Exception
+    version = utils.depot_tools_version()
+    self.assertEqual(version, 'recipes.cfg-42')
+
+  @mock.patch('subprocess.check_output')
+  @mock.patch('os.path.getmtime')
+  def testVersionWithNoGit(self, mock_subprocess, mock_getmtime):
+    mock_subprocess.side_effect = Exception
+    mock_getmtime.side_effect = Exception
+    version = utils.depot_tools_version()
+    self.assertEqual(version, 'unknown')
+
+
+if __name__ == '__main__':
+  logging.basicConfig(
+      level=logging.DEBUG if '-v' in sys.argv else logging.ERROR)
+  sys.exit(
+      coverage_utils.covered_main(
+          (os.path.join(DEPOT_TOOLS_ROOT, 'git_cache.py')),
+          required_percentage=0))

utils.py

@@ -0,0 +1,25 @@
+# Copyright 2022 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.
+
+import os
+import subprocess
+
+
+def depot_tools_version():
+  depot_tools_root = os.path.dirname(os.path.abspath(__file__))
+  try:
+    commit_hash = subprocess.check_output(['git', 'rev-parse', 'HEAD'],
+                                          cwd=depot_tools_root).decode(
+                                              'utf-8', 'ignore')
+    return 'git-%s' % commit_hash
+  except Exception:
+    pass
+
+  # git check failed, let's check last modification of frequently checked file
+  try:
+    mtime = os.path.getmtime(
+        os.path.join(depot_tools_root, 'infra', 'config', 'recipes.cfg'))
+    return 'recipes.cfg-%d' % (mtime)
+  except Exception:
+    return 'unknown'