Added script to generate stats on a git checkout

infra/tools/antibody/test/compute_stats_test.py

Index: infra/tools/antibody/test/compute_stats_test.py
diff --git a/infra/tools/antibody/test/compute_stats_test.py b/infra/tools/antibody/test/compute_stats_test.py
new file mode 100644
index 0000000000000000000000000000000000000000..71fef0a5194e227f216d869ad614f683eebe9e44
--- /dev/null
+++ b/infra/tools/antibody/test/compute_stats_test.py
@@ -0,0 +1,39 @@
+# Copyright 2015 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 unittest
+
+from infra.tools.antibody import compute_stats
+
+
+class TestComputeStats(unittest.TestCase):
+  def test_ratio_calculator(self):
+    reg_num = [['2014-01', 1], ['2014-02', 3], ['2014-07', 5]]
+    reg_den = [['2014-07', 10], ['2014-02', 6], ['2014-01', 9]]
+    reg_ratio = compute_stats.ratio_calculator(reg_num, reg_den)
+    self.assertEqual(reg_ratio,
+                     [['2014-01', 0.111], ['2014-02', 0.5], ['2014-07', 0.5]])
+
+    zero_num = [['2014-01', 1], ['2014-02', 0], ['2014-07', 5]]
+    zero_den = [['2014-07', 10], ['2014-02', 0], ['2014-01', 0]]
+    zero_ratio = compute_stats.ratio_calculator(zero_num, zero_den)
+    self.assertEqual(zero_ratio,
+                     [['2014-01', 0], ['2014-02', 0], ['2014-07', 0.5]])
+
+    missing_num = [['2014-01', 1], ['2014-02', 3], ['2014-07', 5]]
+    missing_den = [['2014-02', 3], ['2014-07', 10]]
+    missing_ratio = compute_stats.ratio_calculator(missing_num, missing_den)
+    self.assertEqual(missing_ratio,
+                     [['2014-02', 1.0], ['2014-07', 0.5]])
+
+    extra_num = [['2014-01', 1], ['2014-02', 3], ['2014-07', 5]]
+    extra_den = [['2014-02', 3], ['2015-07', 5], ['2015-07', 5]]
+    extra_ratio = compute_stats.ratio_calculator(extra_num, extra_den)
+    self.assertEqual(extra_ratio, [['2014-02', 1.0]])
+
+  def test_totaled_ratio_calculator(self):
+    ratio = compute_stats.totaled_ratio_calculator(3, 7)
+    self.assertEqual(ratio, 0.429)
+    self.assertRaises(ZeroDivisionError,
+        compute_stats.totaled_ratio_calculator, 5, 0)