Add assertIn for test use.

1 files changed, 8 insertions, 0 deletions

diff --git a/test/test_testing.py b/test/test_testing.py
index 316dbc1b..c632f3b5 100644
--- a/test/test_testing.py
+++ b/test/test_testing.py
@@ -92,6 +92,14 @@ class TestingTest(TestCase):
         self.assertFalse(False)
         self.assertRaises(AssertionError, self.assertFalse, True)
 
+    def test_assert_contains(self):
+        self.assertIn("abc", "hello abc")
+        self.assertIn("abc", ["xyz", "abc", "foo"])
+        self.assertIn("abc", {'abc': 1, 'xyz': 2})
+        self.assertRaises(AssertionError, self.assertIn, "abc", "xyz")
+        self.assertRaises(AssertionError, self.assertIn, "abc", ["x", "xabc"])
+        self.assertRaises(AssertionError, self.assertIn, "abc", {'x':'abc'})
+
 
 class CoverageTestTest(CoverageTest):
     """Test the methods in `CoverageTest`."""