Run tests with warnings as errors.

domdfcoding · domdfcoding · commit 75a892fb46a5 · 2022-01-17T22:59:29.000Z
diff --git a/tox.ini b/tox.ini
@@ -179,6 +179,9 @@ package = flake8_slots
 [pytest]
 addopts = --color yes --durations 25
 timeout = 300
+filterwarnings =
+    error
+    ignore:can't resolve package from __spec__ or __package__, falling back on __name__ and __path__:ImportWarning
 
 [dep_checker]
 allowed_unused = flake8
