Make iteritems detection more like the rest of backward.py, and add a test of it.

2 files changed, 21 insertions, 3 deletions

diff --git a/coverage/backward.py b/coverage/backward.py
index 54e4625..4894bac 100644
--- a/coverage/backward.py
+++ b/coverage/backward.py
@@ -75,14 +75,16 @@ except NameError:
     range = range
 
 # A function to iterate listlessly over a dict's items.
-if "iteritems" in dir({}):
+try:
+    {}.iteritems
+except AttributeError:
     def iitems(d):
         """Produce the items from dict `d`."""
-        return d.iteritems()
+        return d.items()
 else:
     def iitems(d):
         """Produce the items from dict `d`."""
-        return d.items()
+        return d.iteritems()
 
 # Exec is a statement in Py2, a function in Py3
 if sys.version_info >= (3, 0):
diff --git a/tests/test_backward.py b/tests/test_backward.py
new file mode 100644
index 0000000..63ee20d
--- /dev/null
+++ b/tests/test_backward.py
@@ -0,0 +1,16 @@
+# -*- coding: utf-8 -*-
+"""Tests that our version shims in backward.py are working."""
+
+from coverage.backward import iitems
+from tests.backunittest import TestCase
+
+
+class BackwardTest(TestCase):
+    """Tests of things from backward.py."""
+
+    run_in_temp_dir = False
+
+    def test_iitems(self):
+        d = {'a': 1, 'b': 2, 'c': 3}
+        items = [('a', 1), ('b', 2), ('c', 3)]
+        self.assertSameElements(list(iitems(d)), items)