TestCase: loose assertion strength
The position index might also be `0`, which is interpreted as `False`
and leads to an `AssertionError`.
@@ -231,7 +231,7 @@ class DefaultTestCase(tc.TestCase):
result = self.get_last_execution_result()
if result is not None and result.has_test_exceptions():
position = result.get_first_position_of_thrown_exception()
- assert position
+ assert position is not None
# The position might not be valid anymore.
if position < self.size():
return position
