Make test suite fail on warnings.

anntzer · anntzer · commit 0cd91947710d · 2019-05-05T00:57:09.000+02:00
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -6073,7 +6073,8 @@ def invert(x):
 
         secax(0.2, functions=(invert, invert))
         secax(0.4, functions=(lambda x: 2 * x, lambda x: x / 2))
-        secax(0.6, functions=(lambda x: x**2, lambda x: x**(1/2)))
+        with pytest.warns(RuntimeWarning):  # Needs to be fixed.
+            secax(0.6, functions=(lambda x: x**2, lambda x: x**(1/2)))
         secax(0.8)
 
 
diff --git a/lib/matplotlib/tests/test_cbook.py b/lib/matplotlib/tests/test_cbook.py
@@ -353,10 +353,8 @@ def test_normalize_kwargs_pass(inp, expected, kwargs_to_norm):
 def test_warn_external_frame_embedded_python():
     with patch.object(cbook, "sys") as mock_sys:
         mock_sys._getframe = Mock(return_value=None)
-        with warnings.catch_warnings(record=True) as w:
+        with pytest.warns(UserWarning, match=r"\Adummy\Z"):
             cbook._warn_external("dummy")
-    assert len(w) == 1
-    assert str(w[0].message) == "dummy"
 
 
 def test_to_prestep():
diff --git a/pytest.ini b/pytest.ini
@@ -7,3 +7,6 @@ python_files = test_*.py
 markers =
     backend: Set alternate Matplotlib backend temporarily.
     style: Set alternate Matplotlib style temporarily.
+
+filterwarnings =
+    error
