TST: Force qt?_module fixture to be run first.

QuLogic · QuLogic · commit e101040dea6c · 2018-09-20T16:02:29.000-04:00
If it's not run first, then the `mpl_test_settings` fixture will attempt
to switch backends before the skip is triggered.
diff --git a/lib/matplotlib/tests/test_backend_qt4.py b/lib/matplotlib/tests/test_backend_qt4.py
@@ -8,7 +8,20 @@
 import pytest
 
 
-@pytest.fixture(autouse=True)
+def pytest_generate_tests(metafunc):
+    """
+    Insert qt4_module fixture as *first* fixture.
+
+    It is very important that it is first, because it skips tests when Qt4 is
+    not available. Making it an autouse fixture, or using it as a parameter
+    would not leave it first. If this fixture is not first, then the
+    `mpl_test_settings` fixture will try to switch backends before the skip can
+    be triggered.
+    """
+    metafunc.fixturenames.insert(0, 'qt4_module')
+
+
+@pytest.fixture
 def qt4_module():
     try:
         import PyQt4
diff --git a/lib/matplotlib/tests/test_backend_qt5.py b/lib/matplotlib/tests/test_backend_qt5.py
@@ -8,7 +8,20 @@
 import pytest
 
 
-@pytest.fixture(autouse=True)
+def pytest_generate_tests(metafunc):
+    """
+    Insert qt5_module fixture as *first* fixture.
+
+    It is very important that it is first, because it skips tests when Qt5 is
+    not available. Making it an autouse fixture, or using it as a parameter
+    would not leave it first. If this fixture is not first, then the
+    `mpl_test_settings` fixture will try to switch backends before the skip can
+    be triggered.
+    """
+    metafunc.fixturenames.insert(0, 'qt5_module')
+
+
+@pytest.fixture
 def qt5_module():
     try:
         import PyQt5
