Fix headless tests on Wayland.

QuLogic · QuLogic · commit a4087b087674 · 2020-12-09T19:10:50.000-05:00
Since #17396, backends now check for Wayland settings as part of headless detection. However, the headless tests do not override those settings. When running on Wayland, they thus think the display exists when they are not supposed to.
diff --git a/lib/matplotlib/tests/test_backends_interactive.py b/lib/matplotlib/tests/test_backends_interactive.py
@@ -12,6 +12,7 @@
 import pytest
 
 import matplotlib as mpl
+from matplotlib import _c_internal_utils
 
 
 # Minimal smoke-testing of the backends for which the dependencies are
@@ -40,8 +41,9 @@ def _get_testable_interactive_backends():
     ]:
         reason = None
         missing = [dep for dep in deps if not importlib.util.find_spec(dep)]
-        if sys.platform == "linux" and not os.environ.get("DISPLAY"):
-            reason = "$DISPLAY is unset"
+        if (sys.platform == "linux" and
+                not _c_internal_utils.display_is_valid()):
+            reason = "$DISPLAY and $WAYLAND_DISPLAY are unset"
         elif missing:
             reason = "{} cannot be imported".format(", ".join(missing))
         elif backend == 'macosx' and os.environ.get('TF_BUILD'):
@@ -276,7 +278,8 @@ def test_lazy_linux_headless():
 import sys
 
 # make it look headless
-del os.environ['DISPLAY']
+os.environ.pop('DISPLAY', None)
+os.environ.pop('WAYLAND_DISPLAY', None)
 
 # we should fast-track to Agg
 import matplotlib.pyplot as plt
diff --git a/lib/matplotlib/tests/test_rcparams.py b/lib/matplotlib/tests/test_rcparams.py
@@ -10,7 +10,7 @@
 import pytest
 
 import matplotlib as mpl
-from matplotlib import _api
+from matplotlib import _api, _c_internal_utils
 import matplotlib.pyplot as plt
 import matplotlib.colors as mcolors
 import numpy as np
@@ -476,7 +476,8 @@ def test_rcparams_reset_after_fail():
 @pytest.mark.skipif(sys.platform != "linux", reason="Linux only")
 def test_backend_fallback_headless(tmpdir):
     env = {**os.environ,
-           "DISPLAY": "", "MPLBACKEND": "", "MPLCONFIGDIR": str(tmpdir)}
+           "DISPLAY": "", "WAYLAND_DISPLAY": "",
+           "MPLBACKEND": "", "MPLCONFIGDIR": str(tmpdir)}
     with pytest.raises(subprocess.CalledProcessError):
         subprocess.run(
             [sys.executable, "-c",
@@ -487,8 +488,9 @@ def test_backend_fallback_headless(tmpdir):
             env=env, check=True)
 
 
-@pytest.mark.skipif(sys.platform == "linux" and not os.environ.get("DISPLAY"),
-                    reason="headless")
+@pytest.mark.skipif(
+    sys.platform == "linux" and not _c_internal_utils.display_is_valid(),
+    reason="headless")
 def test_backend_fallback_headful(tmpdir):
     pytest.importorskip("tkinter")
     env = {**os.environ, "MPLBACKEND": "", "MPLCONFIGDIR": str(tmpdir)}
