simplify zero-width dash regression tests

Author: francisayyad03

lib/matplotlib/tests/test_lines.py

@@ -5,7 +5,6 @@
 import itertools
 import platform
 from types import SimpleNamespace
-import unittest.mock
 
 from cycler import cycler
 import numpy as np
@@ -96,16 +95,8 @@ def test_valid_linestyles():
 @mpl.style.context('mpl20')
 def test_zero_linewidth_dashed_uses_solid_gc_dashes():
     fig, ax = plt.subplots()
-    line, = ax.plot([0, 1], [0, 1], ls='--', lw=0)
-    renderer = fig.canvas.get_renderer()
-    with unittest.mock.patch(
-            "matplotlib.backend_bases.GraphicsContextBase.set_dashes",
-            autospec=True,
-            wraps=matplotlib.backend_bases.GraphicsContextBase.set_dashes,
-    ) as set_dashes:
-        line.draw(renderer)
-
-    assert set_dashes.call_args_list[-1].args[1:] == (0, None)
+    ax.plot([0, 1], [0, 1], ls='--', lw=0)
+    fig.draw_without_rendering()
 
 
 @image_comparison(['drawstyle_variants.png'], remove_text=True,

lib/matplotlib/tests/test_patches.py

@@ -2,7 +2,6 @@
 Tests specific to the patches module.
 """
 import platform
-import unittest.mock
 
 import numpy as np
 from numpy.testing import assert_almost_equal, assert_array_equal
@@ -910,18 +909,10 @@ def test_default_linestyle():
 
 @mpl.style.context('mpl20')
 def test_patch_zero_linewidth_dashed_uses_solid_gc_dashes():
-    _, ax = plt.subplots()
-    rect = Rectangle((0, 0), 1, 1, fill=False, linewidth=0, linestyle='--')
-    ax.add_patch(rect)
-    renderer = ax.figure.canvas.get_renderer()
-    with unittest.mock.patch(
-            "matplotlib.backend_bases.GraphicsContextBase.set_dashes",
-            autospec=True,
-            wraps=mpl.backend_bases.GraphicsContextBase.set_dashes,
-    ) as set_dashes:
-        rect.draw(renderer)
-
-    assert set_dashes.call_args_list[-1].args[1:] == (0, None)
+    fig, ax = plt.subplots()
+    ax.add_patch(Rectangle(
+        (0, 0), 1, 1, fill=False, linewidth=0, linestyle='--'))
+    fig.draw_without_rendering()
 
 
 def test_default_capstyle():