diff --git a/git_cl.py b/git_cl.py
index 3c8e4acff..d4d190d8d 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -55,6 +55,7 @@ import subprocess2
 import swift_format
 import watchlists
 
+from lib import utils
 from third_party import six
 from six.moves import urllib
 
@@ -6131,7 +6132,6 @@ def CMDlol(parser, args):
 
 
 def CMDversion(parser, args):
-  import utils
   print(utils.depot_tools_version())
 
 
diff --git a/lib/__init__.py b/lib/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/lib/utils.py b/lib/utils.py
new file mode 100644
index 000000000..b7ee4cd07
--- /dev/null
+++ b/lib/utils.py
@@ -0,0 +1,95 @@
+# 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.
+
+""" A collection of commonly used functions across depot_tools.
+"""
+
+import logging
+import os
+import re
+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'
+
+
+def normpath(path):
+  '''Version of os.path.normpath that also changes backward slashes to
+  forward slashes when not running on Windows.
+  '''
+  # This is safe to always do because the Windows version of os.path.normpath
+  # will replace forward slashes with backward slashes.
+  path = path.replace(os.sep, '/')
+  return os.path.normpath(path)
+
+
+def ListRelevantFilesInSourceCheckout(files, root, match_re, exclude_re):
+  """Finds all files that apply to a given set of source files, e.g. PRESUBMIT.
+
+  If inherit-review-settings-ok is present right under root, looks for matches
+  in directories enclosing root.
+
+  Args:
+    files: An iterable container containing file paths.
+    root: Path where to stop searching.
+    match_re: regex to match filename
+    exclude_re: regex to exclude filename
+
+  Return:
+    List of absolute paths of the existing PRESUBMIT.py scripts.
+  """
+  files = [normpath(os.path.join(root, f)) for f in files]
+
+  # List all the individual directories containing files.
+  directories = {os.path.dirname(f) for f in files}
+
+  # Ignore root if inherit-review-settings-ok is present.
+  if os.path.isfile(os.path.join(root, 'inherit-review-settings-ok')):
+    root = None
+
+  # Collect all unique directories that may contain PRESUBMIT.py.
+  candidates = set()
+  for directory in directories:
+    while True:
+      if directory in candidates:
+        break
+      candidates.add(directory)
+      if directory == root:
+        break
+      parent_dir = os.path.dirname(directory)
+      if parent_dir == directory:
+        # We hit the system root directory.
+        break
+      directory = parent_dir
+
+  # Look for PRESUBMIT.py in all candidate directories.
+  results = []
+  for directory in sorted(list(candidates)):
+    try:
+      for f in os.listdir(directory):
+        p = os.path.join(directory, f)
+        if os.path.isfile(p) and re.match(match_re,
+                                          f) and not re.match(exclude_re, f):
+          results.append(p)
+    except OSError:
+      pass
+
+  logging.debug('Presubmit files: %s', ','.join(results))
+  return results
diff --git a/presubmit_support.py b/presubmit_support.py
index 2375d7635..fe6e819aa 100755
--- a/presubmit_support.py
+++ b/presubmit_support.py
@@ -50,6 +50,7 @@ import presubmit_canned_checks
 import rdb_wrapper
 import scm
 import subprocess2 as subprocess  # Exposed through the API.
+from lib import utils
 
 if sys.version_info.major == 2:
   # TODO(1009814): Expose urllib2 only through urllib_request and urllib_error
@@ -69,6 +70,9 @@ _ASKED_FOR_FEEDBACK = False
 # are coming from.
 _SHOW_CALLSTACKS = False
 
+_PRESUBMIT_FILE_REGEX = r'PRESUBMIT.*\.py$'
+_PRESUBMIT_FILE_EXCLUDE = r'PRESUBMIT_test'
+
 
 def time_time():
   # Use this so that it can be mocked in tests without interfering with python
@@ -285,16 +289,6 @@ class ThreadPool(object):
     return self._messages
 
 
-def normpath(path):
-  '''Version of os.path.normpath that also changes backward slashes to
-  forward slashes when not running on Windows.
-  '''
-  # This is safe to always do because the Windows version of os.path.normpath
-  # will replace forward slashes with backward slashes.
-  path = path.replace(os.sep, '/')
-  return os.path.normpath(path)
-
-
 def _RightHandSideLinesImpl(affected_files):
   """Implements RightHandSideLines for InputApi and GclChange."""
   for af in affected_files:
@@ -729,15 +723,17 @@ class InputApi(object):
     script, or subdirectories thereof. Note that files are listed using the OS
     path separator, so backslashes are used as separators on Windows.
     """
-    dir_with_slash = normpath(self.PresubmitLocalPath())
+    dir_with_slash = utils.normpath(self.PresubmitLocalPath())
     # normpath strips trailing path separators, so the trailing separator has to
     # be added after the normpath call.
     if len(dir_with_slash) > 0:
       dir_with_slash += os.path.sep
 
-    return list(filter(
-        lambda x: normpath(x.AbsoluteLocalPath()).startswith(dir_with_slash),
-        self.change.AffectedFiles(include_deletes, file_filter)))
+    return list(
+        filter(
+            lambda x: utils.normpath(x.AbsoluteLocalPath()).startswith(
+                dir_with_slash),
+            self.change.AffectedFiles(include_deletes, file_filter)))
 
   def LocalPaths(self):
     """Returns local paths of input_api.AffectedFiles()."""
@@ -958,7 +954,7 @@ class _GitDiffCache(_DiffCache):
           current_diff.append(x)
 
       self._diffs_by_file = dict(
-        (normpath(path), ''.join(diff)) for path, diff in diffs.items())
+          (utils.normpath(path), ''.join(diff)) for path, diff in diffs.items())
 
     if path not in self._diffs_by_file:
       # SCM didn't have any diff on this file. It could be that the file was not
@@ -997,7 +993,7 @@ class AffectedFile(object):
     because presubmit checks are run with CWD=PresubmitLocalPath() (which is
     often != client root).
     """
-    return normpath(self._path)
+    return utils.normpath(self._path)
 
   def AbsoluteLocalPath(self):
     """Returns the absolute path of this file on the local disk.
@@ -1358,59 +1354,6 @@ class GitChange(Change):
         cwd=root).decode('utf-8', 'ignore').splitlines()
 
 
-def ListRelevantPresubmitFiles(files, root):
-  """Finds all presubmit files that apply to a given set of source files.
-
-  If inherit-review-settings-ok is present right under root, looks for
-  PRESUBMIT.py in directories enclosing root.
-
-  Args:
-    files: An iterable container containing file paths.
-    root: Path where to stop searching.
-
-  Return:
-    List of absolute paths of the existing PRESUBMIT.py scripts.
-  """
-  files = [normpath(os.path.join(root, f)) for f in files]
-
-  # List all the individual directories containing files.
-  directories = {os.path.dirname(f) for f in files}
-
-  # Ignore root if inherit-review-settings-ok is present.
-  if os.path.isfile(os.path.join(root, 'inherit-review-settings-ok')):
-    root = None
-
-  # Collect all unique directories that may contain PRESUBMIT.py.
-  candidates = set()
-  for directory in directories:
-    while True:
-      if directory in candidates:
-        break
-      candidates.add(directory)
-      if directory == root:
-        break
-      parent_dir = os.path.dirname(directory)
-      if parent_dir == directory:
-        # We hit the system root directory.
-        break
-      directory = parent_dir
-
-  # Look for PRESUBMIT.py in all candidate directories.
-  results = []
-  for directory in sorted(list(candidates)):
-    try:
-      for f in os.listdir(directory):
-        p = os.path.join(directory, f)
-        if os.path.isfile(p) and re.match(
-            r'PRESUBMIT.*\.py$', f) and not f.startswith('PRESUBMIT_test'):
-          results.append(p)
-    except OSError:
-      pass
-
-  logging.debug('Presubmit files: %s', ','.join(results))
-  return results
-
-
 class GetPostUploadExecuter(object):
   def __init__(self, change, gerrit_obj, use_python3):
     """
@@ -1491,15 +1434,16 @@ def DoPostUploadExecuter(change, gerrit_obj, verbose, use_python3=False):
   """
   python_version = 'Python %s' % sys.version_info.major
   sys.stdout.write('Running %s post upload checks ...\n' % python_version)
-  presubmit_files = ListRelevantPresubmitFiles(
-      change.LocalPaths(), change.RepositoryRoot())
+  presubmit_files = utils.ListRelevantFilesInSourceCheckout(
+      change.LocalPaths(), change.RepositoryRoot(), _PRESUBMIT_FILE_REGEX,
+      _PRESUBMIT_FILE_EXCLUDE)
   if not presubmit_files and verbose:
     sys.stdout.write('Warning, no PRESUBMIT.py found.\n')
   results = []
   executer = GetPostUploadExecuter(change, gerrit_obj, use_python3)
   # The root presubmit file should be executed after the ones in subdirectories.
   # i.e. the specific post upload hooks should run before the general ones.
-  # Thus, reverse the order provided by ListRelevantPresubmitFiles.
+  # Thus, reverse the order.
   presubmit_files.reverse()
 
   for filename in presubmit_files:
@@ -1771,8 +1715,9 @@ def DoPresubmitChecks(change,
       sys.stdout.write('Running %s presubmit upload checks ...\n' %
                        python_version)
     start_time = time_time()
-    presubmit_files = ListRelevantPresubmitFiles(
-        change.AbsoluteLocalPaths(), change.RepositoryRoot())
+    presubmit_files = utils.ListRelevantFilesInSourceCheckout(
+        change.AbsoluteLocalPaths(), change.RepositoryRoot(),
+        _PRESUBMIT_FILE_REGEX, _PRESUBMIT_FILE_EXCLUDE)
     if not presubmit_files and verbose:
       sys.stdout.write('Warning, no PRESUBMIT.py found.\n')
     results = []
@@ -2123,7 +2068,6 @@ def main(argv=None):
           options.use_python3,
           options.no_diffs)
   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(),
diff --git a/tests/presubmit_unittest.py b/tests/presubmit_unittest.py
index 00a65bab8..5a1ee9dfb 100755
--- a/tests/presubmit_unittest.py
+++ b/tests/presubmit_unittest.py
@@ -47,6 +47,7 @@ import presubmit_support as presubmit
 import rdb_wrapper
 import scm
 import subprocess2 as subprocess
+from lib import utils
 
 
 # Shortcut.
@@ -220,7 +221,6 @@ index fe3de7b..54ae6e1 100755
 class PresubmitUnittest(PresubmitTestsBase):
   """General presubmit_support.py tests (excluding InputApi and OutputApi)."""
 
-  _INHERIT_SETTINGS = 'inherit-review-settings-ok'
   fake_root_dir = '/foo/bar'
 
   def testCannedCheckFilter(self):
@@ -231,78 +231,6 @@ class PresubmitUnittest(PresubmitTestsBase):
       self.assertEqual(canned.CheckOwners(None, None), [])
     self.assertEqual(canned.CheckOwners, orig)
 
-  def testListRelevantPresubmitFiles(self):
-    files = [
-        'blat.cc',
-        os.path.join('foo', 'haspresubmit', 'yodle', 'smart.h'),
-        os.path.join('moo', 'mat', 'gat', 'yo.h'),
-        os.path.join('foo', 'luck.h'),
-    ]
-
-    known_files = [
-        os.path.join(self.fake_root_dir, 'PRESUBMIT.py'),
-        os.path.join(self.fake_root_dir, 'foo', 'haspresubmit', 'PRESUBMIT.py'),
-        os.path.join(
-            self.fake_root_dir, 'foo', 'haspresubmit', 'yodle', 'PRESUBMIT.py'),
-    ]
-    os.path.isfile.side_effect = lambda f: f in known_files
-
-    dirs_with_presubmit = [
-        self.fake_root_dir,
-        os.path.join(self.fake_root_dir, 'foo', 'haspresubmit'),
-        os.path.join(self.fake_root_dir, 'foo', 'haspresubmit', 'yodle'),
-    ]
-    os.listdir.side_effect = (
-        lambda d: ['PRESUBMIT.py'] if d in dirs_with_presubmit else [])
-
-    presubmit_files = presubmit.ListRelevantPresubmitFiles(
-        files, self.fake_root_dir)
-    self.assertEqual(presubmit_files, known_files)
-
-  def testListUserPresubmitFiles(self):
-    files = ['blat.cc',]
-
-    os.path.isfile.side_effect = lambda f: 'PRESUBMIT' in f
-    os.listdir.return_value = [
-        'PRESUBMIT.py', 'PRESUBMIT_test.py', 'PRESUBMIT-user.py']
-
-    presubmit_files = presubmit.ListRelevantPresubmitFiles(
-        files, self.fake_root_dir)
-    self.assertEqual(presubmit_files, [
-        os.path.join(self.fake_root_dir, 'PRESUBMIT.py'),
-        os.path.join(self.fake_root_dir, 'PRESUBMIT-user.py'),
-    ])
-
-  def testListRelevantPresubmitFilesInheritSettings(self):
-    sys_root_dir = self._OS_SEP
-    root_dir = os.path.join(sys_root_dir, 'foo', 'bar')
-    inherit_path = os.path.join(root_dir, self._INHERIT_SETTINGS)
-    files = [
-        'test.cc',
-        os.path.join('moo', 'test2.cc'),
-        os.path.join('zoo', 'test3.cc')
-    ]
-
-    known_files = [
-        inherit_path,
-        os.path.join(sys_root_dir, 'foo', 'PRESUBMIT.py'),
-        os.path.join(sys_root_dir, 'foo', 'bar', 'moo', 'PRESUBMIT.py'),
-    ]
-    os.path.isfile.side_effect = lambda f: f in known_files
-
-    dirs_with_presubmit = [
-        os.path.join(sys_root_dir, 'foo'),
-        os.path.join(sys_root_dir, 'foo', 'bar','moo'),
-    ]
-    os.listdir.side_effect = (
-        lambda d: ['PRESUBMIT.py'] if d in dirs_with_presubmit else [])
-
-    presubmit_files = presubmit.ListRelevantPresubmitFiles(files, root_dir)
-    self.assertEqual(presubmit_files, [
-        os.path.join(sys_root_dir, 'foo', 'PRESUBMIT.py'),
-        os.path.join(sys_root_dir, 'foo', 'bar', 'moo', 'PRESUBMIT.py')
-    ])
-
   def testTagLineRe(self):
     m = presubmit.Change.TAG_LINE_RE.match(' BUG =1223, 1445  \t')
     self.assertIsNotNone(m)
@@ -994,11 +922,11 @@ def CheckChangeOnCommit(input_api, output_api):
         presubmit.main(
             ['--root', self.fake_root_dir, 'random_file.txt', '--post_upload']))
 
-  @mock.patch('presubmit_support.ListRelevantPresubmitFiles')
+  @mock.patch('lib.utils.ListRelevantFilesInSourceCheckout')
   def testMainUnversioned(self, *_mocks):
     gclient_utils.FileRead.return_value = ''
     scm.determine_scm.return_value = None
-    presubmit.ListRelevantPresubmitFiles.return_value = [
+    utils.ListRelevantFilesInSourceCheckout.return_value = [
         os.path.join(self.fake_root_dir, 'PRESUBMIT.py')
     ]
 
@@ -1006,14 +934,14 @@ def CheckChangeOnCommit(input_api, output_api):
         0,
         presubmit.main(['--root', self.fake_root_dir, 'random_file.txt']))
 
-  @mock.patch('presubmit_support.ListRelevantPresubmitFiles')
+  @mock.patch('lib.utils.ListRelevantFilesInSourceCheckout')
   def testMainUnversionedChecksFail(self, *_mocks):
     gclient_utils.FileRead.return_value = (
         'USE_PYTHON3 = ' + str(sys.version_info.major == 3) + '\n'
         'def CheckChangeOnUpload(input_api, output_api):\n'
         '  return [output_api.PresubmitError("!!")]\n')
     scm.determine_scm.return_value = None
-    presubmit.ListRelevantPresubmitFiles.return_value = [
+    utils.ListRelevantFilesInSourceCheckout.return_value = [
         os.path.join(self.fake_root_dir, 'PRESUBMIT.py')
     ]
 
@@ -1285,26 +1213,22 @@ class InputApiUnittest(PresubmitTestsBase):
     # Doesn't filter much
     got_files = input_api.AffectedFiles()
     self.assertEqual(len(got_files), 7)
-    self.assertEqual(got_files[0].LocalPath(), presubmit.normpath(files[0][1]))
-    self.assertEqual(got_files[1].LocalPath(), presubmit.normpath(files[1][1]))
-    self.assertEqual(got_files[2].LocalPath(), presubmit.normpath(files[2][1]))
-    self.assertEqual(got_files[3].LocalPath(), presubmit.normpath(files[3][1]))
-    self.assertEqual(got_files[4].LocalPath(), presubmit.normpath(files[4][1]))
-    self.assertEqual(got_files[5].LocalPath(), presubmit.normpath(files[5][1]))
-    self.assertEqual(got_files[6].LocalPath(), presubmit.normpath(files[6][1]))
+    self.assertEqual(got_files[0].LocalPath(), utils.normpath(files[0][1]))
+    self.assertEqual(got_files[1].LocalPath(), utils.normpath(files[1][1]))
+    self.assertEqual(got_files[2].LocalPath(), utils.normpath(files[2][1]))
+    self.assertEqual(got_files[3].LocalPath(), utils.normpath(files[3][1]))
+    self.assertEqual(got_files[4].LocalPath(), utils.normpath(files[4][1]))
+    self.assertEqual(got_files[5].LocalPath(), utils.normpath(files[5][1]))
+    self.assertEqual(got_files[6].LocalPath(), utils.normpath(files[6][1]))
     # Ignores weird because of check_list, third_party because of skip_list,
     # binary isn't a text file and being deleted doesn't exist. The rest is
     # outside foo/.
     rhs_lines = list(input_api.RightHandSideLines(None))
     self.assertEqual(len(rhs_lines), 14)
-    self.assertEqual(rhs_lines[0][0].LocalPath(),
-                     presubmit.normpath(files[0][1]))
-    self.assertEqual(rhs_lines[3][0].LocalPath(),
-                     presubmit.normpath(files[0][1]))
-    self.assertEqual(rhs_lines[7][0].LocalPath(),
-                     presubmit.normpath(files[4][1]))
-    self.assertEqual(rhs_lines[13][0].LocalPath(),
-                     presubmit.normpath(files[4][1]))
+    self.assertEqual(rhs_lines[0][0].LocalPath(), utils.normpath(files[0][1]))
+    self.assertEqual(rhs_lines[3][0].LocalPath(), utils.normpath(files[0][1]))
+    self.assertEqual(rhs_lines[7][0].LocalPath(), utils.normpath(files[4][1]))
+    self.assertEqual(rhs_lines[13][0].LocalPath(), utils.normpath(files[4][1]))
 
   def testInputApiFilterSourceFile(self):
     files = [
@@ -1344,10 +1268,10 @@ class InputApiUnittest(PresubmitTestsBase):
     got_files = input_api.AffectedSourceFiles(None)
     self.assertEqual(len(got_files), 4)
     # blat.cc, another.h, WebKit.cpp, and blink.cc remain.
-    self.assertEqual(got_files[0].LocalPath(), presubmit.normpath(files[0][1]))
-    self.assertEqual(got_files[1].LocalPath(), presubmit.normpath(files[4][1]))
-    self.assertEqual(got_files[2].LocalPath(), presubmit.normpath(files[5][1]))
-    self.assertEqual(got_files[3].LocalPath(), presubmit.normpath(files[7][1]))
+    self.assertEqual(got_files[0].LocalPath(), utils.normpath(files[0][1]))
+    self.assertEqual(got_files[1].LocalPath(), utils.normpath(files[4][1]))
+    self.assertEqual(got_files[2].LocalPath(), utils.normpath(files[5][1]))
+    self.assertEqual(got_files[3].LocalPath(), utils.normpath(files[7][1]))
 
   def testDefaultFilesToCheckFilesToSkipFilters(self):
     def f(x):
@@ -1430,8 +1354,7 @@ class InputApiUnittest(PresubmitTestsBase):
     for item in files:
       results = list(filter(input_api.FilterSourceFile, item[0]))
       for i in range(len(results)):
-        self.assertEqual(results[i].LocalPath(),
-                          presubmit.normpath(item[1][i]))
+        self.assertEqual(results[i].LocalPath(), utils.normpath(item[1][i]))
       # Same number of expected results.
       self.assertEqual(sorted([f.LocalPath().replace(os.sep, '/')
                                 for f in results]),
@@ -1491,7 +1414,7 @@ class InputApiUnittest(PresubmitTestsBase):
     self.assertEqual(got_files[1].LocalPath(), 'eecaee')
 
   def testGetAbsoluteLocalPath(self):
-    normpath = presubmit.normpath
+    normpath = utils.normpath
     # Regression test for bug of presubmit stuff that relies on invoking
     # SVN (e.g. to get mime type of file) not working unless gcl invoked
     # from the client root (e.g. if you were at 'src' and did 'cd base' before
@@ -1512,13 +1435,11 @@ class InputApiUnittest(PresubmitTestsBase):
     self.assertEqual(affected_files[0].LocalPath(), normpath('isdir'))
     self.assertEqual(affected_files[1].LocalPath(), normpath('isdir/blat.cc'))
     # Absolute paths should be prefixed
-    self.assertEqual(
-        affected_files[0].AbsoluteLocalPath(),
-        presubmit.normpath(os.path.join(self.fake_root_dir, 'isdir')))
+    self.assertEqual(affected_files[0].AbsoluteLocalPath(),
+                     utils.normpath(os.path.join(self.fake_root_dir, 'isdir')))
     self.assertEqual(
         affected_files[1].AbsoluteLocalPath(),
-        presubmit.normpath(os.path.join(
-            self.fake_root_dir, 'isdir/blat.cc')))
+        utils.normpath(os.path.join(self.fake_root_dir, 'isdir/blat.cc')))
 
     # New helper functions need to work
     paths_from_change = change.AbsoluteLocalPaths()
@@ -1530,17 +1451,14 @@ class InputApiUnittest(PresubmitTestsBase):
         is_committing=True, gerrit_obj=None, verbose=False)
     paths_from_api = api.AbsoluteLocalPaths()
     self.assertEqual(len(paths_from_api), 1)
-    self.assertEqual(
-        paths_from_change[0],
-        presubmit.normpath(os.path.join(self.fake_root_dir, 'isdir')))
+    self.assertEqual(paths_from_change[0],
+                     utils.normpath(os.path.join(self.fake_root_dir, 'isdir')))
     self.assertEqual(
         paths_from_change[1],
-        presubmit.normpath(os.path.join(self.fake_root_dir, 'isdir',
-                                        'blat.cc')))
+        utils.normpath(os.path.join(self.fake_root_dir, 'isdir', 'blat.cc')))
     self.assertEqual(
         paths_from_api[0],
-        presubmit.normpath(os.path.join(self.fake_root_dir, 'isdir',
-                                        'blat.cc')))
+        utils.normpath(os.path.join(self.fake_root_dir, 'isdir', 'blat.cc')))
 
   def testDeprecated(self):
     change = presubmit.Change(
@@ -1665,7 +1583,7 @@ class AffectedFileUnittest(PresubmitTestsBase):
   def testAffectedFile(self):
     gclient_utils.FileRead.return_value = 'whatever\ncookie'
     af = presubmit.GitAffectedFile('foo/blat.cc', 'M', self.fake_root_dir, None)
-    self.assertEqual(presubmit.normpath('foo/blat.cc'), af.LocalPath())
+    self.assertEqual(utils.normpath('foo/blat.cc'), af.LocalPath())
     self.assertEqual('M', af.Action())
     self.assertEqual(['whatever', 'cookie'], af.NewContents())
 
diff --git a/tests/utils_test.py b/tests/utils_test.py
index 89620dbeb..a7bc8b91b 100755
--- a/tests/utils_test.py
+++ b/tests/utils_test.py
@@ -17,13 +17,10 @@ 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
+from lib 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()
@@ -45,6 +42,91 @@ class GitCacheTest(unittest.TestCase):
     self.assertEqual(version, 'unknown')
 
 
+class ListRelevantFilesInSourceCheckoutTest(unittest.TestCase):
+  fake_root_dir = os.path.join(os.sep, 'foo', 'bar')
+  _INHERIT_SETTINGS = 'inherit-review-settings-ok'
+
+  def setUp(self):
+    mock.patch('os.listdir').start()
+    mock.patch('os.path.isfile').start()
+
+  def testListRelevantPresubmitFiles(self):
+    files = [
+        'blat.cc',
+        os.path.join('foo', 'haspresubmit', 'yodle', 'smart.h'),
+        os.path.join('moo', 'mat', 'gat', 'yo.h'),
+        os.path.join('foo', 'luck.h'),
+    ]
+
+    known_files = [
+        os.path.join(self.fake_root_dir, 'PRESUBMIT.py'),
+        os.path.join(self.fake_root_dir, 'foo', 'haspresubmit', 'PRESUBMIT.py'),
+        os.path.join(self.fake_root_dir, 'foo', 'haspresubmit', 'yodle',
+                     'PRESUBMIT.py'),
+    ]
+    os.path.isfile.side_effect = lambda f: f in known_files
+
+    dirs_with_presubmit = [
+        self.fake_root_dir,
+        os.path.join(self.fake_root_dir, 'foo', 'haspresubmit'),
+        os.path.join(self.fake_root_dir, 'foo', 'haspresubmit', 'yodle'),
+    ]
+    os.listdir.side_effect = (
+        lambda d: ['PRESUBMIT.py'] if d in dirs_with_presubmit else [])
+
+    presubmit_files = utils.ListRelevantFilesInSourceCheckout(
+        files, self.fake_root_dir, r'PRESUBMIT.*', r'PRESUBMIT_test')
+    self.assertEqual(presubmit_files, known_files)
+
+  def testListUserPresubmitFiles(self):
+    files = [
+        'blat.cc',
+    ]
+
+    os.path.isfile.side_effect = lambda f: 'PRESUBMIT' in f
+    os.listdir.return_value = [
+        'PRESUBMIT.py', 'PRESUBMIT_test.py', 'PRESUBMIT-user.py'
+    ]
+
+    presubmit_files = utils.ListRelevantFilesInSourceCheckout(
+        files, self.fake_root_dir, r'PRESUBMIT.*', r'PRESUBMIT_test')
+    self.assertEqual(presubmit_files, [
+        os.path.join(self.fake_root_dir, 'PRESUBMIT.py'),
+        os.path.join(self.fake_root_dir, 'PRESUBMIT-user.py'),
+    ])
+
+  def testListRelevantPresubmitFilesInheritSettings(self):
+    sys_root_dir = os.sep
+    root_dir = os.path.join(sys_root_dir, 'foo', 'bar')
+    inherit_path = os.path.join(root_dir, self._INHERIT_SETTINGS)
+    files = [
+        'test.cc',
+        os.path.join('moo', 'test2.cc'),
+        os.path.join('zoo', 'test3.cc')
+    ]
+
+    known_files = [
+        inherit_path,
+        os.path.join(sys_root_dir, 'foo', 'PRESUBMIT.py'),
+        os.path.join(sys_root_dir, 'foo', 'bar', 'moo', 'PRESUBMIT.py'),
+    ]
+    os.path.isfile.side_effect = lambda f: f in known_files
+
+    dirs_with_presubmit = [
+        os.path.join(sys_root_dir, 'foo'),
+        os.path.join(sys_root_dir, 'foo', 'bar', 'moo'),
+    ]
+    os.listdir.side_effect = (
+        lambda d: ['PRESUBMIT.py'] if d in dirs_with_presubmit else [])
+
+    presubmit_files = utils.ListRelevantFilesInSourceCheckout(
+        files, root_dir, r'PRESUBMIT.*', r'PRESUBMIT_test')
+    self.assertEqual(presubmit_files, [
+        os.path.join(sys_root_dir, 'foo', 'PRESUBMIT.py'),
+        os.path.join(sys_root_dir, 'foo', 'bar', 'moo', 'PRESUBMIT.py')
+    ])
+
+
 if __name__ == '__main__':
   logging.basicConfig(
       level=logging.DEBUG if '-v' in sys.argv else logging.ERROR)
diff --git a/utils.py b/utils.py
deleted file mode 100644
index 3f16ce98b..000000000
--- a/utils.py
+++ /dev/null
@@ -1,25 +0,0 @@
-# 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'