[Findit] Initial code of findit for crash. Add scorers to apply heuristic rules.

appengine/findit/crash/scorers/test/min_distance_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.
+
+from crash.results import Result, MatchResult
+from crash.scorers.min_distance import MinDistance
+from crash.scorers.test.scorer_test_suite import ScorerTestSuite
+
+
+class MinDistanceTest(ScorerTestSuite):
+
+  def testGetMetric(self):
+    dummy_changelog = self._GetDummyChangeLog()
+    match_result = MatchResult(dummy_changelog, 'src/', '')
+    match_result.min_distance = 0
+
+    self.assertEqual(MinDistance().GetMetric(match_result), 0)
+
+    result = Result(dummy_changelog, 'src/', '')
+    self.assertEqual(MinDistance().GetMetric(result), None)
+
+  def testScore(self):
+    self.assertEqual(MinDistance().Score(0), 1)
+    self.assertEqual(MinDistance().Score(30), 0.8)
+    self.assertEqual(MinDistance().Score(60), 0)
+
+  def testReason(self):
+    self.assertEqual(MinDistance().Reason(0, 1),
+                     'Minimum distance to crashed line is 0')
+    self.assertEqual(MinDistance().Reason(60, 0),
+                     '')