Use more specific asserts throughout tests

In the event that a test fails, a more specific assert will usually
provide more useful information about what went wrong.

Prefer assertIs(..., True) over assertTrue() to assert the type as well
as the truthy value. This is recommended by Python:

https://docs.python.org/3/library/unittest.html#unittest.TestCase.assertTrue

> Note that this is equivalent to bool(expr) is True and not to expr is
> True (use assertIs(expr, True) for the latter). This method should
> also be avoided when more specific methods are available (e.g.
> assertEqual(a, b) instead of assertTrue(a == b)), because they provide
> a better error message in case of failure.

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/test_extensions.py b/tests/test_extensions.py
index b4c0779..bd78777 100644
--- a/tests/test_extensions.py
+++ b/tests/test_extensions.py
@@ -447,7 +447,7 @@ line 3
                 'fenced_code'
             ]
         )
-        self.assertTrue('<code class="language-python">' in md.convert(text))
+        self.assertIn('<code class="language-python">', md.convert(text))
 
     def testFencedLanguageDoubleEscape(self):
         """ Test entity escape logic in fences. """