tests: Report details about failed assertions in tests.base

tests/base.py

@@ -114,7 +114,10 @@ class IntegrationTest(object):
 
         # For silent commands, there should be no output
         if silent is not None:
-            assert silent == bool(not result)
+            if silent:
+                assert not result
+            else:
+                assert result
 
             # Multiline-evaluate the regex
             if regex:

tests/conftest.py

@@ -2,6 +2,11 @@
 import pytest
 import re
 
+
+# enable assertion introspection for the common code in tests.base
+pytest.register_assert_rewrite('tests.base')
+
+
 markup_headers = {
     'default': {
         'HEADER1': "= %s =",