Refactor infra git libs and testing.

infra/libs/decorators/test/decorators_test.py

Index: infra/libs/decorators/test/decorators_test.py
diff --git a/infra/libs/decorators/test/decorators_test.py b/infra/libs/decorators/test/decorators_test.py
new file mode 100644
index 0000000000000000000000000000000000000000..e1a0c9a3ab59f3e6d8b167490e25f18db33d3f5e
--- /dev/null
+++ b/infra/libs/decorators/test/decorators_test.py
@@ -0,0 +1,60 @@
+# Copyright 2014 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.libs import decorators
+
+
+class TestCachedProperty(unittest.TestCase):
+  def setUp(self):
+    self.calls = calls = []
+    class Foo(object):
+      def __init__(self, success=True, override=None):
+        self.success = success
+        self.override = override
+
+      @decorators.cached_property
+      def happy(self):
+        calls.append(1)
+        if self.override is not None:
+          self._happy = self.override  # pylint: disable=W0201
+        if not self.success:
+          raise Exception('nope')
+        return 'days'
+    self.Foo = Foo
+
+  def testBasic(self):
+    f = self.Foo()
+    self.assertEqual(f.happy, 'days')
+    self.assertEqual(f.happy, 'days')
+    self.assertEqual(sum(self.calls), 1)
+
+  def testBareReturnsSelf(self):
+    self.assertIsInstance(self.Foo.happy, decorators.cached_property)
+
+  def testOverride(self):
+    f = self.Foo(override='cowabunga!')
+    self.assertEqual(f.happy, 'cowabunga!')
+    self.assertEqual(f.happy, 'cowabunga!')
+    self.assertEqual(sum(self.calls), 1)
+
+  def testNoCache(self):
+    f = self.Foo(False)
+    with self.assertRaises(Exception):
+      f.happy  # pylint: disable=W0104
+    f.success = True
+    self.assertEqual(f.happy, 'days')
+    self.assertEqual(sum(self.calls), 2)
+
+  def testDelRerunsMethodOnce(self):
+    f = self.Foo()
+    self.assertEqual(f.happy, 'days')
+    self.assertEqual(f.happy, 'days')
+    del f.happy
+    self.assertEqual(f.happy, 'days')
+    del f.happy
+    del f.happy
+    self.assertEqual(f.happy, 'days')
+    self.assertEqual(sum(self.calls), 3)