[pinpoint] Add message in bug when there are no change points.

dashboard/dashboard/pinpoint/models/job.py

Index: dashboard/dashboard/pinpoint/models/job.py
diff --git a/dashboard/dashboard/pinpoint/models/job.py b/dashboard/dashboard/pinpoint/models/job.py
index a2bf223084ee3787ffaf551eec2d48e5847920e5..d6ff7b4845c77891af3d76470146c37c2e8d08cd 100644
--- a/dashboard/dashboard/pinpoint/models/job.py
+++ b/dashboard/dashboard/pinpoint/models/job.py
@@ -114,7 +114,7 @@ class Job(ndb.Model):
     self._PostBugComment('started')
 
   def Complete(self):
-    self._PostBugComment('completed')
+    self._PostBugComment('completed', include_differences=True)
 
   def Fail(self):
     self.exception = traceback.format_exc()
@@ -159,27 +159,22 @@ class Job(ndb.Model):
       d.update(self.state.AsDict())
     return d
 
-  def _PostBugComment(self, status):
+  def _PostBugComment(self, status, include_differences=False):
     if not self.bug_id:
       return
 
     title = '%s Pinpoint job %s.' % (_ROUND_PUSHPIN, status)
     header = '\n'.join((title, self.url))
 
-    # Include list of Changes.
     change_details = []
-    for _, change in self.state.Differences():
-      # TODO: Store the commit info in the Commit.
-      commit = change.last_commit
-      commit_info = gitiles_service.CommitInfo(commit.repository_url,
-                                               commit.git_hash)
-      subject = commit_info['message'].split('\n', 1)[0]
-      author = commit_info['author']['email']
-      time = commit_info['committer']['time']
-
-      byline = 'By %s %s %s' % (author, _MIDDLE_DOT, time)
-      git_link = commit.repository + '@' + commit.git_hash
-      change_details.append('\n'.join((subject, byline, git_link)))
+    if include_differences:
+      # Include list of Changes.
+      differences = self.state.Differences()
+      if differences:
+        for _, change in differences:
+          change_details.append(_FormatChangeForBug(change))
+      else:
+        change_details.append('No change points found.')

[sullivan, 2017/09/18 20:55:47]

This might be a little confusing to users. "No significant performance change
found in range?"

[shatch, 2017/09/18 21:00:14]

Kinda wonder if people will ask what this means, might be cleared if it said
something more along the lines of 'Couldn't reproduce a difference' or
something. We could just land this and see though.

[perezju, 2017/09/19 11:56:07]

It would also help figure out the right wording if, for the case when there
_are_ changes, we provided some sort of title; i.e. what are these CLs? Why are
you telling me about them? Maybe:

'Significant performance changes found after these CLs/this CL:'

???

 
     comment = '\n\n'.join([header] + change_details)
 
@@ -353,6 +348,20 @@ class _JobState(object):
     return _UNKNOWN
 
 
+def _FormatChangeForBug(change):
+  # TODO: Store the commit info in the Commit.
+  commit = change.last_commit
+  commit_info = gitiles_service.CommitInfo(commit.repository_url,
+                                           commit.git_hash)
+  subject = commit_info['message'].split('\n', 1)[0]
+  author = commit_info['author']['email']
+  time = commit_info['committer']['time']
+
+  byline = 'By %s %s %s' % (author, _MIDDLE_DOT, time)
+  git_link = commit.repository + '@' + commit.git_hash
+  return '\n'.join((subject, byline, git_link))
+
+
 def _CombineResultsPerQuest(attempts):
   aggregate_results = collections.defaultdict(list)
   for attempt in attempts: