[pinpoint] Calculate distances between Changes.

dashboard/dashboard/pinpoint/models/change/change_test.py

Index: dashboard/dashboard/pinpoint/models/change/change_test.py
diff --git a/dashboard/dashboard/pinpoint/models/change/change_test.py b/dashboard/dashboard/pinpoint/models/change/change_test.py
index d47ff4b4330fc5e8f454c266c88cf8f2064d8346..ce9a0342353c60c437b3a9e910e8687636010788 100644
--- a/dashboard/dashboard/pinpoint/models/change/change_test.py
+++ b/dashboard/dashboard/pinpoint/models/change/change_test.py
@@ -162,34 +162,34 @@ class MidpointTest(_ChangeTest):
   def testSameChange(self):
     change_a = change.Change((commit.Commit('chromium', 0),))
     change_b = change.Change((commit.Commit('chromium', 0),))
-    with self.assertRaises(commit.NonLinearError):
-      change.Change.Midpoint(change_a, change_b)
+    expected = change_a, (0, 0)
+    self.assertEqual(change.Change.Midpoint(change_a, change_b), expected)
 
   def testAdjacentWithNoDepsRoll(self):
     change_a = change.Change((commit.Commit('chromium', 0),))
     change_b = change.Change((commit.Commit('chromium', 1),))
-    with self.assertRaises(commit.NonLinearError):
-      change.Change.Midpoint(change_a, change_b)
+    expected = change_a, (0, 1)
+    self.assertEqual(change.Change.Midpoint(change_a, change_b), expected)
 
   def testAdjacentWithDepsRoll(self):
     change_a = change.Change((commit.Commit('chromium', 4),))
     change_b = change.Change((commit.Commit('chromium', 5),))
     expected = change.Change((commit.Commit('chromium', 4),
-                              commit.Commit('catapult', 4)))
+                              commit.Commit('catapult', 4))), (4, 5)
     self.assertEqual(change.Change.Midpoint(change_a, change_b), expected)
 
   def testNotAdjacent(self):
     change_a = change.Change((commit.Commit('chromium', 0),))
     change_b = change.Change((commit.Commit('chromium', 9),))
-    self.assertEqual(change.Change.Midpoint(change_a, change_b),
-                     change.Change((commit.Commit('chromium', 4),)))
+    expected = change.Change((commit.Commit('chromium', 4),)), (4, 5)
+    self.assertEqual(change.Change.Midpoint(change_a, change_b), expected)
 
   def testDepsRollLeft(self):
     change_a = change.Change((commit.Commit('chromium', 4),))
     change_b = change.Change((commit.Commit('chromium', 4),
                               commit.Commit('catapult', 4)))
     expected = change.Change((commit.Commit('chromium', 4),
-                              commit.Commit('catapult', 2)))
+                              commit.Commit('catapult', 2))), (2, 2)
     self.assertEqual(change.Change.Midpoint(change_a, change_b), expected)
 
   def testDepsRollRight(self):
@@ -197,7 +197,7 @@ class MidpointTest(_ChangeTest):
                               commit.Commit('catapult', 4)))
     change_b = change.Change((commit.Commit('chromium', 5),))
     expected = change.Change((commit.Commit('chromium', 4),
-                              commit.Commit('catapult', 6)))
+                              commit.Commit('catapult', 6))), (2, 3)
     self.assertEqual(change.Change.Midpoint(change_a, change_b), expected)
 
   def testAdjacentWithDepsRollAndDepAlreadyOverridden(self):
@@ -205,5 +205,5 @@ class MidpointTest(_ChangeTest):
     change_b = change.Change((commit.Commit('chromium', 5),
                               commit.Commit('catapult', 4)))
     expected = change.Change((commit.Commit('chromium', 4),
-                              commit.Commit('catapult', 2)))
+                              commit.Commit('catapult', 2))), (2, 2)
     self.assertEqual(change.Change.Midpoint(change_a, change_b), expected)