[pinpoint] Calculate distances between Changes.

dashboard/dashboard/pinpoint/models/change/commit_test.py

 # Copyright 2016 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 mock
 
 from dashboard.common import namespaced_stored_object
 from dashboard.common import testing_common
 from dashboard.pinpoint.models.change import commit
 
@@ skipping 99 matching lines @@
 
 
 class MidpointTest(_CommitTest):
 
   @mock.patch('dashboard.services.gitiles_service.CommitRange')
   def testSuccess(self, commit_range):
     commit_range.return_value = [
         {'commit': 'babe852'},
         {'commit': 'b57345e'},
         {'commit': '949b36d'},
         {'commit': '1ef4789'},

[perezju, 2017/09/19 15:58:05]

these are a bit hard to think about, can you replace them with "hash_1",
"hash_2", etc.? (in reverse order, I assume?)

And same for other MidpointTest's below.

     ]
 
     commit_a = commit.Commit('chromium', '0e57e2b')
     commit_b = commit.Commit('chromium', 'babe852')
-    self.assertEqual(commit.Commit.Midpoint(commit_a, commit_b),
-                     commit.Commit('chromium', '949b36d'))
+    expected = commit.Commit('chromium', '949b36d'), (2, 2)
+    self.assertEqual(commit.Commit.Midpoint(commit_a, commit_b), expected)
 

[perezju, 2017/09/19 15:58:05]

Can you also add a success test with an even number of commits in between?

   def testSameCommit(self):
     commit_a = commit.Commit('chromium', '0e57e2b')
     commit_b = commit.Commit('chromium', '0e57e2b')
-    self.assertEqual(commit.Commit.Midpoint(commit_a, commit_b), commit_a)
+    expected = commit_a, (0, 0)
+    self.assertEqual(commit.Commit.Midpoint(commit_a, commit_b), expected)
 
   @mock.patch('dashboard.services.gitiles_service.CommitRange')
   def testAdjacentCommits(self, commit_range):
     commit_range.return_value = [{'commit': 'b57345e'}]
 
     commit_a = commit.Commit('chromium', '949b36d')
     commit_b = commit.Commit('chromium', 'b57345e')
-    self.assertEqual(commit.Commit.Midpoint(commit_a, commit_b), commit_a)
+    expected = commit_a, (0, 1)
+    self.assertEqual(commit.Commit.Midpoint(commit_a, commit_b), expected)
 
   def testRaisesWithDifferingRepositories(self):
     commit_a = commit.Commit('chromium', '0e57e2b')
     commit_b = commit.Commit('not_chromium', 'babe852')
     with self.assertRaises(commit.NonLinearError):
       commit.Commit.Midpoint(commit_a, commit_b)
 
   @mock.patch('dashboard.services.gitiles_service.CommitRange')
   def testRaisesWithEmptyRange(self, commit_range):
     commit_range.return_value = []
 
     commit_b = commit.Commit('chromium', 'b57345e')
     commit_a = commit.Commit('chromium', '949b36d')
     with self.assertRaises(commit.NonLinearError):
       commit.Commit.Midpoint(commit_a, commit_b)