Test and fix Version.truncate()

Calling `Version.truncate("build")` should return a fresh instance, as
caught in #141

Closes: #141, #142

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/test_base.py b/tests/test_base.py
index e6a3733..73d1b08 100755
--- a/tests/test_base.py
+++ b/tests/test_base.py
@@ -395,6 +395,16 @@ class VersionTestCase(unittest.TestCase):
         self.assertEqual(v.prerelease, ())
         self.assertEqual(v.build, ())
 
+    def test_truncate(self):
+        v = base.Version("3.2.1-pre+build")
+        self.assertEqual(v.truncate("build"), v)
+        self.assertIsNot(v.truncate("build"), v)
+        self.assertEqual(v.truncate("prerelease"), base.Version("3.2.1-pre"))
+        self.assertEqual(v.truncate("patch"), base.Version("3.2.1"))
+        self.assertEqual(v.truncate(), base.Version("3.2.1"))
+        self.assertEqual(v.truncate("minor"), base.Version("3.2.0"))
+        self.assertEqual(v.truncate("major"), base.Version("3.0.0"))
+
 
 class SpecItemTestCase(unittest.TestCase):
     if sys.version_info[0] <= 2: