fix test_stairs_update

timhoffm · timhoffm · commit b2fd5ed4b9b1 · 2020-09-28T22:18:05.000+02:00
We have to use fixed view limits because stairs() does autoscale, but
updating data does not. Otherwise the test and ref way of generating
the plot would end up with different view limits.
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -1878,9 +1878,12 @@ def test_stairs_fill(fig_test, fig_ref):
 
 @check_figures_equal(extensions=['png'])
 def test_stairs_update(fig_test, fig_ref):
+    # fixed ylim because stairs() does autoscale, but updating data does not
+    ylim = -3, 4
     # Test
     test_ax = fig_test.add_subplot()
     h = test_ax.stairs([1, 2, 3])
+    test_ax.set_ylim(ylim)
     h.set_values([3, 2, 1])
     h.set_edges(np.arange(4)+2)
     h.set_data([1, 2, 1], np.arange(4)/2)
@@ -1891,9 +1894,10 @@ def test_stairs_update(fig_test, fig_ref):
     h.set_baseline(-2)
     assert h.get_baseline() == -2
 
-    # # Ref
+    # Ref
     ref_ax = fig_ref.add_subplot()
     h = ref_ax.stairs([1, 2, 3], baseline=-2)
+    ref_ax.set_ylim(ylim)
 
 
 def test_stairs_invalid_nan():
