test: add warnings tests

Author: Rogdham

CHANGELOG.md

@@ -14,6 +14,10 @@ adheres to [Semantic Versioning](https://semver.org/).
 - Allow to `seek` past the end of the fileobj
 - Calling `len` on a fileobj gives its length, and `bool` tells if it is empty
 
+### :house: Internal
+
+- Test that no warnings are generated
+
 ## [0.1.2] - 2021-09-19
 
 [0.1.2]: https://github.com/rogdham/python-xz/releases/tag/v0.1.2

pytest.ini

@@ -2,6 +2,10 @@
 addopts =
     --cov
     --strict-markers
+filterwarnings =
+    error
+    # issue in standard lib for Python 3.7.12[pypy-7.3.6-final]
+    ignore:Using or importing the ABCs from 'collections':DeprecationWarning:_lzma
 markers =
     generate_integration_files
     integration