[owners] Add tests for Depot Tools owners client.

Change-Id: I988f5b866560d5839a1121c7129099ffe125fdce
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2545108
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>

owners.py

@@ -201,7 +201,7 @@ class Database(object):
     self._check_reviewers(reviewers)
     self.load_data_needed_for(files)
 
-    return set(f for f in files if not self._is_obj_covered_by(f, reviewers))
+    return set(f for f in files if not self.is_covered_by(f, reviewers))
 
   def _check_paths(self, files):
     def _is_under(f, pfx):
@@ -214,7 +214,7 @@ class Database(object):
     _assert_is_collection(reviewers)
     assert all(self.email_regexp.match(r) for r in reviewers), reviewers
 
-  def _is_obj_covered_by(self, objname, reviewers):
+  def is_covered_by(self, objname, reviewers):
     reviewers = list(reviewers) + [EVERYONE]
     while True:
       for reviewer in reviewers:

owners_client.py

@@ -4,6 +4,7 @@
 
 import os
 
+import gerrit_util
 import owners
 import scm
 
@@ -52,16 +53,19 @@ class OwnersClient(object):
 
 class DepotToolsClient(OwnersClient):
   """Implement OwnersClient using owners.py Database."""
-  def __init__(self, host, root, branch):
+  def __init__(self, host, root, fopen, os_path, branch):
     super(DepotToolsClient, self).__init__(host)
     self._root = root
     self._branch = branch
-    self._db = owners.Database(root, open, os.path)
-    self._db.override_files({
+    self._db = owners.Database(root, fopen, os_path)
+    self._db.override_files = self._GetOriginalOwnersFiles()
+
+  def _GetOriginalOwnersFiles(self):
+    return {
       f: scm.GIT.GetOldContents(self._root, f, self._branch)
       for _, f in scm.GIT.CaptureStatus(self._root, self._branch)
       if os.path.basename(f) == 'OWNERS'
-    })
+    }
 
   def ListOwnersForFile(self, _project, _branch, path):
     return sorted(self._db.all_possible_owners([path], None))
@@ -75,7 +79,7 @@ class DepotToolsClient(OwnersClient):
     reviewers = [r['email'] for r in data['reviewers']['REVIEWER']]
 
     # Get reviewers that have approved this change
-    label = change['labels']['Code-Review']
+    label = data['labels']['Code-Review']
     max_value = max(int(v) for v in label['values'])
     approvers = [v['email'] for v in label['all'] if v['value'] == max_value]
 

tests/owners_client_test.py

@@ -0,0 +1,102 @@
+# Copyright (c) 2020 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 sys
+import unittest
+
+if sys.version_info.major == 2:
+  import mock
+else:
+  from unittest import mock
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+import gerrit_util
+import owners
+import owners_client
+
+from testing_support import filesystem_mock
+
+
+_TEST_CHANGE = {
+  "labels": {
+    "Code-Review": {
+      "all": [
+        {
+          "value": 1,
+          "email": "approver@example.com",
+        }
+      ],
+      "values": {
+        "-1": "Don't submit as-is",
+        " 0": "No score",
+        "+1": "Looks good to me"
+      },
+    },
+  },
+  "reviewers": {
+    "REVIEWER": [
+      {"email": "approver@example.com"},
+      {"email": "reviewer@example.com"},
+    ],
+  },
+  "current_revision": "cb90826d03533d6c4e1f0e974ebcbfd7a6f42406",
+  "revisions": {
+    "cb90826d03533d6c4e1f0e974ebcbfd7a6f42406": {
+      "files": {
+        "approved.cc": {},
+        "reviewed.h": {},
+        "bar/insufficient.py": {},
+      },
+    },
+  },
+}
+
+
+
+class DepotToolsClientTest(unittest.TestCase):
+  def setUp(self):
+    self.repo = filesystem_mock.MockFileSystem(files={
+        '/OWNERS': '\n'.join([
+            'per-file approved.cc=approver@example.com',
+            'per-file reviewed.h=reviewer@example.com',
+            'missing@example.com',
+        ]),
+        '/approved.cc': '',
+        '/reviewed.h': '',
+        '/bar/insufficient_reviewers.py': '',
+        '/bar/everyone/OWNERS': '*',
+        '/bar/everyone/foo.txt': '',
+    })
+    self.files = self.repo.files
+    self.root = '/'
+    self.fopen = self.repo.open_for_reading
+    mock.patch(
+        'owners_client.DepotToolsClient._GetOriginalOwnersFiles',
+        return_value={}).start()
+    self.addCleanup(mock.patch.stopall)
+
+  def testListOwners(self):
+    client = owners_client.DepotToolsClient(
+        'host', '/', self.fopen, self.repo, 'branch')
+    self.assertEquals(
+        ['*', 'missing@example.com'],
+        client.ListOwnersForFile('project', 'branch', 'bar/everyone/foo.txt'))
+
+  @mock.patch('gerrit_util.GetChange', return_value=_TEST_CHANGE)
+  def testGetChangeApprovalStatus(self, _mock):
+    client = owners_client.DepotToolsClient(
+        'host', '/', self.fopen, self.repo, 'branch')
+    self.assertEquals(
+        {
+            'approved.cc': owners_client.APPROVED,
+            'reviewed.h': owners_client.PENDING,
+            'bar/insufficient.py': owners_client.INSUFFICIENT_REVIEWERS,
+        },
+        client.GetChangeApprovalStatus('changeid'))
+
+
+if __name__ == '__main__':
+  unittest.main()