[presubmit][owners] Skip owners check when Bot-Review is +1

Add support for Bot-Review label to allow trusted bots to
bypass owners checks.

Bug: 1093627
Change-Id: Ie7398041e9e32fd87bb415b239b5ec0a4740e1ec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2530516
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Reviewed-by: Yulan Lin <yulanlin@google.com>

presubmit_canned_checks.py

@@ -1122,6 +1122,11 @@ def CheckOwnersFormat(input_api, output_api):
 
 
 def CheckOwners(input_api, output_api, source_file_filter=None):
+  # Skip OWNERS check when Bot-Commit label is approved.
+  if (input_api.change.issue
+      and input_api.gerrit.IsBotCommitApproved(input_api.change.issue)):
+    return []
+
   affected_files = set([f.LocalPath() for f in
       input_api.change.AffectedFiles(file_filter=source_file_filter)])
   owners_db = input_api.owners_db

presubmit_support.py

@@ -433,20 +433,26 @@ class GerritAccessor(object):
       ref = 'refs/heads/%s' % ref
     return ref
 
+  def _GetApproversForLabel(self, issue, label):
+    change_info = self.GetChangeInfo(issue)
+    label_info = change_info.get('labels', {}).get(label, {})
+    values = label_info.get('values', {}).keys()
+    if not values:
+      return []
+    max_value = max(int(v) for v in values)
+    return [v for v in label_info.get('all', [])
+            if v.get('value', 0) == max_value]
+
+  def IsBotCommitApproved(self, issue):
+    return bool(self._GetApproversForLabel(issue, 'Bot-Commit'))
+
   def GetChangeOwner(self, issue):
     return self.GetChangeInfo(issue)['owner']['email']
 
   def GetChangeReviewers(self, issue, approving_only=True):
     changeinfo = self.GetChangeInfo(issue)
     if approving_only:
-      labelinfo = changeinfo.get('labels', {}).get('Code-Review', {})
-      values = labelinfo.get('values', {}).keys()
-      try:
-        max_value = max(int(v) for v in values)
-        reviewers = [r for r in labelinfo.get('all', [])
-                     if r.get('value', 0) == max_value]
-      except ValueError:  # values is the empty list
-        reviewers = []
+      reviewers = self._GetApproversForLabel(issue, 'Code-Review')
     else:
       reviewers = changeinfo.get('reviewers', {}).get('REVIEWER', [])
     return [r.get('email') for r in reviewers]

tests/presubmit_unittest.py

@@ -2751,6 +2751,33 @@ the current line as well!
         response=response,
         expected_output='')
 
+  def testCannedCheckOwners_BotCommit(self):
+    response = {
+      "owner": {"email": "john@example.com"},
+      "labels": {"Bot-Commit": {
+        u'all': [
+          {
+            u'email': u'bot@example.com',
+            u'value': 1
+          },
+        ],
+        u'approved': {u'email': u'bot@example.org'},
+        u'default_value': 0,
+        u'values': {u' 0': u'No score',
+                    u'+1': u'Looks good to me'},
+      }},
+      "reviewers": {"REVIEWER": [{u'email': u'bot@example.com'}]},
+    }
+    self.AssertOwnersWorks(approvers=set(),
+        response=response,
+        is_committing=True,
+        expected_output='')
+
+    self.AssertOwnersWorks(approvers=set(),
+        is_committing=False,
+        response=response,
+        expected_output='')
+
   def testCannedCheckOwners_Approved(self):
     response = {
       "owner": {"email": "john@example.com"},