TST: Simplify image testing decorator calls

QuLogic · QuLogic · commit 33228083a207 · 2026-02-15T02:51:47.000+05:30
If a single extension is being tested, then as a shortcut, it can be
specified in the basename directly. Also, the default for
`check_figures_equal` is to test only `.png` now, so no need to specify
that.
diff --git a/doc/devel/testing.rst b/doc/devel/testing.rst
@@ -153,6 +153,15 @@ tests it::
        fig, ax = plt.subplots()
        ax.plot(range(10), linestyle=(0, (3, 3)), lw=5)
 
+If you wish to compare only a single extension, then that may be included in the
+baseline image name as a shortcut::
+
+   @image_comparison(baseline_images=['line_dashes.png'], remove_text=True,
+                     style='mpl20')
+   def test_line_dashes():
+       fig, ax = plt.subplots()
+       ax.plot(range(10), linestyle=(0, (3, 3)), lw=5)
+
 The first time this test is run, there will be no baseline image to compare
 against, so the test will fail.  Copy the output images (in this case
 :file:`result_images/test_lines/test_line_dashes.png`) to the correct
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -919,8 +919,7 @@ def test_structured_data():
     axs[1].plot("ones", "twos", "r", data=pts)
 
 
-@image_comparison(['aitoff_proj'], extensions=["png"],
-                  remove_text=True, style='mpl20')
+@image_comparison(['aitoff_proj.png'], remove_text=True, style='mpl20')
 def test_aitoff_proj():
     """
     Test aitoff projection ref.:
@@ -1410,7 +1409,7 @@ def test_pcolormesh():
     ax3.pcolormesh(Qx, Qz, Zm, shading="gouraud")
 
 
-@image_comparison(['pcolormesh_small'], extensions=["eps"])
+@image_comparison(['pcolormesh_small.eps'])
 def test_pcolormesh_small():
     n = 3
     x = np.linspace(-1.5, 1.5, n)
@@ -2915,7 +2914,7 @@ def test_scatter_marker(self):
                     edgecolors=['k', 'r', 'g', 'b'],
                     marker=verts)
 
-    @image_comparison(['scatter_2D'], remove_text=True, extensions=['png'])
+    @image_comparison(['scatter_2D.png'], remove_text=True)
     def test_scatter_2D(self):
         x = np.arange(3)
         y = np.arange(2)
@@ -5683,8 +5682,7 @@ def test_axline_args():
         plt.draw()
 
 
-@image_comparison(['vlines_basic', 'vlines_with_nan', 'vlines_masked'],
-                  extensions=['png'])
+@image_comparison(['vlines_basic.png', 'vlines_with_nan.png', 'vlines_masked.png'])
 def test_vlines():
     # normal
     x1 = [2, 3, 4, 5, 7]
@@ -5730,8 +5728,7 @@ def test_vlines_default():
         assert mpl.colors.same_color(lines.get_color(), 'red')
 
 
-@image_comparison(['hlines_basic', 'hlines_with_nan', 'hlines_masked'],
-                  extensions=['png'])
+@image_comparison(['hlines_basic.png', 'hlines_with_nan.png', 'hlines_masked.png'])
 def test_hlines():
     # normal
     y1 = [2, 3, 4, 5, 7]
@@ -5795,8 +5792,7 @@ def test_lines_with_colors(fig_test, fig_ref, data):
                                         colors=expect_color, linewidth=5)
 
 
-@image_comparison(['vlines_hlines_blended_transform'],
-                  extensions=['png'], style='mpl20')
+@image_comparison(['vlines_hlines_blended_transform.png'], style='mpl20')
 def test_vlines_hlines_blended_transform():
     t = np.arange(5.0, 10.0, 0.1)
     s = np.exp(-t) + np.sin(2 * np.pi * t) + 10
@@ -6492,8 +6488,8 @@ def test_pie_default():
             autopct='%1.1f%%', shadow=True, startangle=90)
 
 
-@image_comparison(['pie_linewidth_0', 'pie_linewidth_0', 'pie_linewidth_0'],
-                  extensions=['png'], style='mpl20', tol=0.01)
+@image_comparison(['pie_linewidth_0.png', 'pie_linewidth_0.png', 'pie_linewidth_0.png'],
+                  style='mpl20', tol=0.01)
 def test_pie_linewidth_0():
     # The slices will be ordered and plotted counter-clockwise.
     labels = 'Frogs', 'Hogs', 'Dogs', 'Logs'
diff --git a/lib/matplotlib/tests/test_bbox_tight.py b/lib/matplotlib/tests/test_bbox_tight.py
@@ -167,8 +167,8 @@ def test_noop_tight_bbox():
     assert im.shape == (7, 10, 4)
 
 
-@image_comparison(['bbox_inches_fixed_aspect'], extensions=['png'],
-                  remove_text=True, savefig_kwarg={'bbox_inches': 'tight'})
+@image_comparison(['bbox_inches_fixed_aspect.png'], remove_text=True,
+                  savefig_kwarg={'bbox_inches': 'tight'})
 def test_bbox_inches_fixed_aspect():
     with plt.rc_context({'figure.constrained_layout.use': True}):
         fig, ax = plt.subplots()
@@ -177,9 +177,8 @@ def test_bbox_inches_fixed_aspect():
         ax.set_aspect('equal')
 
 
-@image_comparison(['bbox_inches_inset_rasterized'], extensions=['pdf'],
-                  remove_text=True, savefig_kwarg={'bbox_inches': 'tight'},
-                  style='mpl20')
+@image_comparison(['bbox_inches_inset_rasterized.pdf'], remove_text=True,
+                  savefig_kwarg={'bbox_inches': 'tight'}, style='mpl20')
 def test_bbox_inches_inset_rasterized():
     fig, ax = plt.subplots()
 
diff --git a/lib/matplotlib/tests/test_collections.py b/lib/matplotlib/tests/test_collections.py
@@ -491,7 +491,7 @@ def test_polycollection_close():
     ax.set_ylim3d(0, 4)
 
 
-@check_figures_equal(extensions=["png"])
+@check_figures_equal()
 def test_scalarmap_change_cmap(fig_test, fig_ref):
     # Ensure that changing the colormap of a 3D scatter after draw updates the colors.
 
@@ -1314,8 +1314,7 @@ def test_set_offset_units():
     np.testing.assert_allclose(off0, sc.get_offsets())
 
 
-@image_comparison(baseline_images=["test_check_masked_offsets"],
-                  extensions=["png"], remove_text=True, style="mpl20")
+@image_comparison(["test_check_masked_offsets.png"], remove_text=True, style="mpl20")
 def test_check_masked_offsets():
     # Check if masked data is respected by scatter
     # Ref: Issue #24545
diff --git a/lib/matplotlib/tests/test_colorbar.py b/lib/matplotlib/tests/test_colorbar.py
@@ -154,13 +154,12 @@ def test_colorbar_extension_inverted_axis(orientation, extend, expected):
 
 # TODO: tighten tolerance after baseline image is regenerated for text overhaul
 @pytest.mark.parametrize('use_gridspec', [True, False])
-@image_comparison(['cbar_with_orientation',
-                   'cbar_locationing',
-                   'double_cbar',
-                   'cbar_sharing',
+@image_comparison(['cbar_with_orientation.png',
+                   'cbar_locationing.png',
+                   'double_cbar.png',
+                   'cbar_sharing.png',
                    ],
-                  extensions=['png'], remove_text=True,
-                  savefig_kwarg={'dpi': 40}, tol=0.05)
+                  remove_text=True, savefig_kwarg={'dpi': 40}, tol=0.05)
 def test_colorbar_positioning(use_gridspec):
     # Remove this line when this test image is regenerated.
     plt.rcParams['pcolormesh.snap'] = False
diff --git a/lib/matplotlib/tests/test_colors.py b/lib/matplotlib/tests/test_colors.py
@@ -847,8 +847,7 @@ def test_cmap_and_norm_from_levels_and_colors():
     ax.tick_params(labelleft=False, labelbottom=False)
 
 
-@image_comparison(baseline_images=['boundarynorm_and_colorbar'],
-                  extensions=['png'], tol=1.0)
+@image_comparison(['boundarynorm_and_colorbar.png'], tol=1.0)
 def test_boundarynorm_and_colorbarbase():
     # Remove this line when this test image is regenerated.
     plt.rcParams['pcolormesh.snap'] = False
diff --git a/lib/matplotlib/tests/test_contour.py b/lib/matplotlib/tests/test_contour.py
@@ -128,8 +128,8 @@ def test_contour_manual_moveto():
 
 
 # TODO: tighten tolerance after baseline image is regenerated for text overhaul
-@image_comparison(['contour_disconnected_segments'],
-                  remove_text=True, style='mpl20', extensions=['png'], tol=0.01)
+@image_comparison(['contour_disconnected_segments.png'],
+                  remove_text=True, style='mpl20', tol=0.01)
 def test_contour_label_with_disconnected_segments():
     x, y = np.mgrid[-1:1:21j, -1:1:21j]
     z = 1 / np.sqrt(0.01 + (x + 0.3) ** 2 + y ** 2)
@@ -172,8 +172,7 @@ def test_given_colors_levels_and_extends():
         plt.colorbar(c, ax=ax)
 
 
-@image_comparison(['contourf_hatch_colors'],
-                  remove_text=True, style='mpl20', extensions=['png'])
+@image_comparison(['contourf_hatch_colors.png'], remove_text=True, style='mpl20')
 def test_hatch_colors():
     fig, ax = plt.subplots()
     cf = ax.contourf([[0, 1], [1, 2]], hatches=['-', '/', '\\', '//'], cmap='gray')
@@ -455,8 +454,7 @@ def test_contour_addlines():
     assert_array_almost_equal(cb.ax.get_ylim(), [114.3091, 9972.30735], 3)
 
 
-@image_comparison(baseline_images=['contour_uneven'],
-                  extensions=['png'], remove_text=True, style='mpl20')
+@image_comparison(['contour_uneven.png'], remove_text=True, style='mpl20')
 def test_contour_uneven():
     # Remove this line when this test image is regenerated.
     plt.rcParams['pcolormesh.snap'] = False
@@ -494,8 +492,7 @@ def test_label_nonagg():
     plt.clabel(plt.contour([[1, 2], [3, 4]]))
 
 
-@image_comparison(baseline_images=['contour_closed_line_loop'],
-                  extensions=['png'], remove_text=True)
+@image_comparison(['contour_closed_line_loop.png'], remove_text=True)
 def test_contour_closed_line_loop():
     # github issue 19568.
     z = [[0, 0, 0], [0, 2, 0], [0, 0, 0], [2, 1, 2]]
@@ -519,8 +516,7 @@ def test_quadcontourset_reuse():
     assert qcs3._contour_generator == qcs1._contour_generator
 
 
-@image_comparison(baseline_images=['contour_manual'],
-                  extensions=['png'], remove_text=True, tol=0.89)
+@image_comparison(['contour_manual.png'], remove_text=True, tol=0.89)
 def test_contour_manual():
     # Manually specifying contour lines/polygons to plot.
     from matplotlib.contour import ContourSet
@@ -545,8 +541,7 @@ def test_contour_manual():
     ContourSet(ax, [2], [segs], [kinds], colors='k', linewidths=3)
 
 
-@image_comparison(baseline_images=['contour_line_start_on_corner_edge'],
-                  extensions=['png'], remove_text=True)
+@image_comparison(['contour_line_start_on_corner_edge.png'], remove_text=True)
 def test_contour_line_start_on_corner_edge():
     fig, ax = plt.subplots(figsize=(6, 5))
 
@@ -680,8 +675,7 @@ def test_algorithm_supports_corner_mask(algorithm):
             plt.contourf(z, algorithm=algorithm, corner_mask=True)
 
 
-@image_comparison(baseline_images=['contour_all_algorithms'],
-                  extensions=['png'], remove_text=True, tol=0.06)
+@image_comparison(['contour_all_algorithms.png'], remove_text=True, tol=0.06)
 def test_all_algorithms():
     algorithms = ['mpl2005', 'mpl2014', 'serial', 'threaded']
 
@@ -858,8 +852,8 @@ def test_allsegs_allkinds():
         assert len(result[1]) == 4
 
 
-@image_comparison(baseline_images=['contour_rasterization'],
-                  extensions=['pdf'], style='mpl20', savefig_kwarg={'dpi': 25})
+@image_comparison(['contour_rasterization.pdf'], savefig_kwarg={'dpi': 25},
+                  style='mpl20')
 def test_contourf_rasterize():
     fig, ax = plt.subplots()
     data = [[0, 1], [1, 0]]
@@ -868,7 +862,7 @@ def test_contourf_rasterize():
     assert cs._rasterized
 
 
-@check_figures_equal(extensions=["png"])
+@check_figures_equal()
 def test_contour_aliases(fig_test, fig_ref):
     data = np.arange(100).reshape((10, 10)) ** 2
     fig_test.add_subplot().contour(data, linestyle=":")
diff --git a/lib/matplotlib/tests/test_patches.py b/lib/matplotlib/tests/test_patches.py
@@ -813,7 +813,7 @@ def test_boxstyle_errors(fmt, match):
         BoxStyle(fmt)
 
 
-@image_comparison(baseline_images=['annulus'], extensions=['png'])
+@image_comparison(['annulus.png'])
 def test_annulus():
 
     fig, ax = plt.subplots()
@@ -825,7 +825,7 @@ def test_annulus():
     ax.set_aspect('equal')
 
 
-@image_comparison(baseline_images=['annulus'], extensions=['png'])
+@image_comparison(['annulus.png'])
 def test_annulus_setters():
 
     fig, ax = plt.subplots()
@@ -846,7 +846,7 @@ def test_annulus_setters():
     ell.angle = 45
 
 
-@image_comparison(baseline_images=['annulus'], extensions=['png'])
+@image_comparison(['annulus.png'])
 def test_annulus_setters2():
 
     fig, ax = plt.subplots()
diff --git a/lib/matplotlib/tests/test_text.py b/lib/matplotlib/tests/test_text.py
@@ -1136,8 +1136,7 @@ def test_empty_annotation_get_window_extent():
 
 
 # TODO: tighten tolerance after baseline image is regenerated for text overhaul
-@image_comparison(baseline_images=['basictext_wrap'],
-                  extensions=['png'], tol=0.3)
+@image_comparison(['basictext_wrap.png'], tol=0.3)
 def test_basic_wrap():
     fig = plt.figure()
     plt.axis([0, 10, 0, 10])
@@ -1154,8 +1153,7 @@ def test_basic_wrap():
 
 
 # TODO: tighten tolerance after baseline image is regenerated for text overhaul
-@image_comparison(baseline_images=['fonttext_wrap'],
-                  extensions=['png'], tol=0.3)
+@image_comparison(['fonttext_wrap.png'], tol=0.3)
 def test_font_wrap():
     fig = plt.figure()
     plt.axis([0, 10, 0, 10])
@@ -1188,8 +1186,8 @@ def test_va_for_angle():
 
 
 # TODO: tighten tolerance after baseline image is regenerated for text overhaul
-@image_comparison(baseline_images=['xtick_rotation_mode'],
-                  remove_text=False, extensions=['png'], style='mpl20', tol=0.3)
+@image_comparison(['xtick_rotation_mode.png'], remove_text=False, style='mpl20',
+                  tol=0.3)
 def test_xtick_rotation_mode():
     fig, ax = plt.subplots(figsize=(12, 1))
     ax.set_yticks([])
@@ -1209,8 +1207,8 @@ def test_xtick_rotation_mode():
 
 
 # TODO: tighten tolerance after baseline image is regenerated for text overhaul
-@image_comparison(baseline_images=['ytick_rotation_mode'],
-                  remove_text=False, extensions=['png'], style='mpl20', tol=0.3)
+@image_comparison(['ytick_rotation_mode.png'], remove_text=False, style='mpl20',
+                  tol=0.3)
 def test_ytick_rotation_mode():
     fig, ax = plt.subplots(figsize=(1, 12))
     ax.set_xticks([])
diff --git a/lib/mpl_toolkits/axes_grid1/tests/test_axes_grid1.py b/lib/mpl_toolkits/axes_grid1/tests/test_axes_grid1.py
@@ -62,7 +62,7 @@ def test_divider_append_axes():
 
 
 # Update style when regenerating the test image
-@image_comparison(['twin_axes_empty_and_removed'], extensions=["png"], tol=1,
+@image_comparison(['twin_axes_empty_and_removed.png'], tol=1,
                   style=('classic', '_classic_test_patch'))
 def test_twin_axes_empty_and_removed():
     # Purely cosmetic font changes (avoid overlap)
diff --git a/lib/mpl_toolkits/mplot3d/tests/test_axes3d.py b/lib/mpl_toolkits/mplot3d/tests/test_axes3d.py
@@ -2200,9 +2200,7 @@ def test_subfigure_simple():
     ax = sf[1].add_subplot(1, 1, 1, projection='3d', label='other')
 
 
-# Update style when regenerating the test image
-@image_comparison(baseline_images=['computed_zorder'], remove_text=True,
-                  extensions=['png'], style=('mpl20'))
+@image_comparison(['computed_zorder.png'], remove_text=True, style='mpl20')
 def test_computed_zorder():
     plt.rcParams['axes3d.automargin'] = True  # Remove when image is regenerated
     fig = plt.figure()
