TST: Make ignore_matplotlibrc a pytest fixture

This allows it to be composed with pytest marks (e.g.
`pytest.mark.skipif`). See astropy#9991.

astropy/conftest.py

@@ -14,6 +14,8 @@
 except ImportError:
     PYTEST_HEADER_MODULES = {}
 
+import pytest
+
 from astropy.tests.helper import enable_deprecations_as_exceptions
 
 try:
@@ -36,6 +38,15 @@
 matplotlibrc_cache = {}
 
 
+@pytest.fixture
+def ignore_matplotlibrc():
+    # This is a fixture for tests that use matplotlib but not pytest-mpl
+    # (which already handles rcParams)
+    from matplotlib import pyplot as plt
+    with plt.style.context({}, after_reset=True):
+        yield
+
+
 def pytest_configure(config):
     builtins._pytest_running = True
     # do not assign to matplotlibrc_cache in function scope

astropy/tests/image_tests.py

@@ -13,13 +13,3 @@
 ROOT = "http://{server}/testing/astropy/2019-08-02T11:38:58.288466/{mpl_version}/"
 IMAGE_REFERENCE_DIR = (ROOT.format(server='data.astropy.org', mpl_version=MPL_VERSION[:3] + '.x') + ',' +
                        ROOT.format(server='www.astropy.org/astropy-data', mpl_version=MPL_VERSION[:3] + '.x'))
-
-
-def ignore_matplotlibrc(func):
-    # This is a decorator for tests that use matplotlib but not pytest-mpl
-    # (which already handles rcParams)
-    @wraps(func)
-    def wrapper(*args, **kwargs):
-        with plt.style.context({}, after_reset=True):
-            return func(*args, **kwargs)
-    return wrapper

astropy/visualization/wcsaxes/tests/test_coordinate_helpers.py

@@ -10,7 +10,6 @@
 
 from astropy.visualization.wcsaxes.core import WCSAxes
 from astropy import units as u
-from astropy.tests.image_tests import ignore_matplotlibrc
 
 ROOT = os.path.join(os.path.dirname(__file__))
 MSX_HEADER = fits.Header.fromtextfile(os.path.join(ROOT, 'data', 'msx_header'))
@@ -20,8 +19,7 @@ def teardown_function(function):
     plt.close('all')
 
 
-@ignore_matplotlibrc
-def test_getaxislabel():
+def test_getaxislabel(ignore_matplotlibrc):
 
     fig = plt.figure()
     ax = WCSAxes(fig, [0.1, 0.1, 0.8, 0.8], aspect='equal')
@@ -53,22 +51,19 @@ def assert_label_draw(ax, x_label, y_label):
     assert pos2.call_count == y_label
 
 
-@ignore_matplotlibrc
-def test_label_visibility_rules_default(ax):
+def test_label_visibility_rules_default(ignore_matplotlibrc, ax):
     assert_label_draw(ax, True, True)
 
 
-@ignore_matplotlibrc
-def test_label_visibility_rules_label(ax):
+def test_label_visibility_rules_label(ignore_matplotlibrc, ax):
 
     ax.coords[0].set_ticklabel_visible(False)
     ax.coords[1].set_ticks(values=[-9999]*u.one)
 
     assert_label_draw(ax, False, False)
 
 
-@ignore_matplotlibrc
-def test_label_visibility_rules_ticks(ax):
+def test_label_visibility_rules_ticks(ignore_matplotlibrc, ax):
 
     ax.coords[0].set_axislabel_visibility_rule('ticks')
     ax.coords[1].set_axislabel_visibility_rule('ticks')
@@ -79,8 +74,7 @@ def test_label_visibility_rules_ticks(ax):
     assert_label_draw(ax, True, False)
 
 
-@ignore_matplotlibrc
-def test_label_visibility_rules_always(ax):
+def test_label_visibility_rules_always(ignore_matplotlibrc, ax):
 
     ax.coords[0].set_axislabel_visibility_rule('always')
     ax.coords[1].set_axislabel_visibility_rule('always')

astropy/visualization/wcsaxes/tests/test_display_world_coordinates.py

@@ -8,7 +8,6 @@
 import astropy.units as u
 from astropy.coordinates import FK5, SkyCoord
 from astropy.io import fits
-from astropy.tests.image_tests import ignore_matplotlibrc
 from astropy.time import Time
 from astropy.utils.data import get_pkg_data_filename
 from astropy.visualization.wcsaxes.core import WCSAxes
@@ -23,8 +22,7 @@ class TestDisplayWorldCoordinate(BaseImageTests):
     def teardown_method(self, method):
         plt.close('all')
 
-    @ignore_matplotlibrc
-    def test_overlay_coords(self, tmpdir):
+    def test_overlay_coords(self, ignore_matplotlibrc, tmpdir):
         wcs = WCS(self.msx_header)
 
         fig = plt.figure(figsize=(4, 4))
@@ -104,8 +102,7 @@ def test_overlay_coords(self, tmpdir):
 
         assert string_world5 == '267.652\xb0 -28\xb046\'23" (world, overlay 3)'
 
-    @ignore_matplotlibrc
-    def test_cube_coords(self, tmpdir):
+    def test_cube_coords(self, ignore_matplotlibrc, tmpdir):
         wcs = WCS(self.cube_header)
 
         fig = plt.figure(figsize=(4, 4))
@@ -128,8 +125,7 @@ def test_cube_coords(self, tmpdir):
         string_pixel = ax._display_world_coords(0.523412, 0.523412)
         assert string_pixel == "0.523412 0.523412 (pixel)"
 
-    @ignore_matplotlibrc
-    def test_cube_coords_uncorr_slicing(self, tmpdir):
+    def test_cube_coords_uncorr_slicing(self, ignore_matplotlibrc, tmpdir):
 
         # Regression test for a bug that occurred with coordinate formatting if
         # some dimensions were uncorrelated and sliced out.

astropy/visualization/wcsaxes/tests/test_misc.py

@@ -15,7 +15,6 @@
 from astropy.io import fits
 from astropy.coordinates import SkyCoord
 from astropy.tests.helper import catch_warnings
-from astropy.tests.image_tests import ignore_matplotlibrc
 
 from astropy.visualization.wcsaxes.core import WCSAxes
 from astropy.visualization.wcsaxes.frame import RectangularFrame, RectangularFrame1D
@@ -31,17 +30,15 @@ def teardown_function(function):
     plt.close('all')
 
 
-@ignore_matplotlibrc
-def test_grid_regression():
+def test_grid_regression(ignore_matplotlibrc):
     # Regression test for a bug that meant that if the rc parameter
     # axes.grid was set to True, WCSAxes would crash upon initalization.
     plt.rc('axes', grid=True)
     fig = plt.figure(figsize=(3, 3))
     WCSAxes(fig, [0.1, 0.1, 0.8, 0.8])
 
 
-@ignore_matplotlibrc
-def test_format_coord_regression(tmpdir):
+def test_format_coord_regression(ignore_matplotlibrc, tmpdir):
     # Regression test for a bug that meant that if format_coord was called by
     # Matplotlib before the axes were drawn, an error occurred.
     fig = plt.figure(figsize=(3, 3))
@@ -74,9 +71,8 @@ def test_format_coord_regression(tmpdir):
 """, sep='\n')
 
 
-@ignore_matplotlibrc
 @pytest.mark.parametrize('grid_type', ['lines', 'contours'])
-def test_no_numpy_warnings(tmpdir, grid_type):
+def test_no_numpy_warnings(ignore_matplotlibrc, tmpdir, grid_type):
 
     # Make sure that no warnings are raised if some pixels are outside WCS
     # (since this is normal)
@@ -95,8 +91,7 @@ def test_no_numpy_warnings(tmpdir, grid_type):
     assert len(ws) == 0
 
 
-@ignore_matplotlibrc
-def test_invalid_frame_overlay():
+def test_invalid_frame_overlay(ignore_matplotlibrc):
 
     # Make sure a nice error is returned if a frame doesn't exist
     ax = plt.subplot(1, 1, 1, projection=WCS(TARGET_HEADER))
@@ -109,8 +104,7 @@ def test_invalid_frame_overlay():
     assert exc.value.args[0] == 'Unknown frame: banana'
 
 
-@ignore_matplotlibrc
-def test_plot_coord_transform():
+def test_plot_coord_transform(ignore_matplotlibrc):
 
     twoMASS_k_header = os.path.join(DATA, '2MASS_k_header')
     twoMASS_k_header = fits.Header.fromtextfile(twoMASS_k_header)
@@ -126,8 +120,7 @@ def test_plot_coord_transform():
         ax.plot_coord(c, 'o', transform=ax.get_transform('galactic'))
 
 
-@ignore_matplotlibrc
-def test_set_label_properties():
+def test_set_label_properties(ignore_matplotlibrc):
 
     # Regression test to make sure that arguments passed to
     # set_xlabel/set_ylabel are passed to the underlying coordinate helpers
@@ -172,8 +165,7 @@ def test_set_label_properties():
 """, sep='\n')
 
 
-@ignore_matplotlibrc
-def test_slicing_warnings(tmpdir):
+def test_slicing_warnings(ignore_matplotlibrc, tmpdir):
 
     # Regression test to make sure that no warnings are emitted by the tick
     # locator for the sliced axis when slicing a cube.
@@ -325,8 +317,7 @@ def test_contour_empty():
         ax.contour(np.zeros((4, 4)), transform=ax.get_transform('world'))
 
 
-@ignore_matplotlibrc
-def test_iterate_coords(tmpdir):
+def test_iterate_coords(ignore_matplotlibrc, tmpdir):
 
     # Regression test for a bug that caused ax.coords to return too few axes
 
@@ -342,8 +333,7 @@ def test_iterate_coords(tmpdir):
     x, y, z = ax.coords
 
 
-@ignore_matplotlibrc
-def test_invalid_slices_errors():
+def test_invalid_slices_errors(ignore_matplotlibrc):
 
     # Make sure that users get a clear message when specifying a WCS with
     # >2 dimensions without giving the 'slices' argument, or if the 'slices'
@@ -413,8 +403,7 @@ def test_invalid_slices_errors():
  """.strip()
 
 
-@ignore_matplotlibrc
-def test_repr():
+def test_repr(ignore_matplotlibrc):
 
     # Unit test to make sure __repr__ looks as expected