Merge pull request matplotlib#6761 from Kojoley/fix-warnings-catching

TST: Fixed warnings catching and counting with `warnings.catch_warnings`

Author: tacaswell

lib/matplotlib/tests/test_axes.py

@@ -2666,6 +2666,7 @@ def test_eventplot_problem_kwargs():
     axobj = fig.add_subplot(111)
 
     with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
         colls = axobj.eventplot(data,
                                 colors=['r', 'b'],
                                 color=['c', 'm'],
@@ -4017,6 +4018,7 @@ def test_pathological_hexbin():
     out = io.BytesIO()
 
     with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
         mylist = [10] * 100
         fig, ax = plt.subplots(1, 1)
         ax.hexbin(mylist, mylist)
@@ -4236,10 +4238,11 @@ def test_errorbar_inputs_shotgun():
 def test_axisbg_warning():
     fig = plt.figure()
     with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
         ax = matplotlib.axes.Axes(fig, [0, 0, 1, 1], axisbg='r')
-    assert len(w) == 1
-    assert (str(w[0].message).startswith(
-            ("The axisbg attribute was deprecated in version 2.0.")))
+        assert len(w) == 1
+        msg = "The axisbg attribute was deprecated in version 2.0."
+        assert str(w[0].message).startswith(msg)
 
 
 @image_comparison(baseline_images=["dash_offset"], remove_text=True)

lib/matplotlib/tests/test_contour.py

@@ -288,8 +288,9 @@ def test_contourf_decreasing_levels():
     # Legacy contouring algorithm gives a warning rather than raising an error,
     # plus a DeprecationWarning.
     with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
         plt.contourf(z, [1.0, 0.0], corner_mask='legacy')
-    assert_equal(len(w), 2)
+        assert_equal(len(w), 2)
 
 
 @cleanup
@@ -299,16 +300,18 @@ def test_vminvmax_warning():
     cs = plt.contourf(z, [0.0, 1.0])
 
     with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
         cs.vmin
-    assert len(w) == 1
-    assert (str(w[0].message).startswith(
-            ("vmin is deprecated and will be removed in 2.2 ")))
+        assert len(w) == 1
+        msg = "vmin is deprecated and will be removed in 2.2 "
+        assert str(w[0].message).startswith(msg)
 
     with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
         cs.vmax
-    assert len(w) == 1
-    assert (str(w[0].message).startswith(
-            ("vmax is deprecated and will be removed in 2.2 ")))
+        assert len(w) == 1
+        msg = "vmax is deprecated and will be removed in 2.2 "
+        assert str(w[0].message).startswith(msg)
 
 
 if __name__ == '__main__':

lib/matplotlib/tests/test_figure.py

@@ -5,6 +5,7 @@
 from six.moves import xrange
 
 from nose.tools import assert_equal, assert_true
+from matplotlib import rcParams
 from matplotlib.testing.decorators import image_comparison, cleanup
 from matplotlib.axes import Axes
 import matplotlib.pyplot as plt
@@ -124,9 +125,10 @@ def test_too_many_figures():
     import warnings
 
     with warnings.catch_warnings(record=True) as w:
-        for i in range(22):
+        warnings.simplefilter("always")
+        for i in range(rcParams['figure.max_open_warning'] + 1):
             fig = plt.figure()
-    assert len(w) == 1
+        assert len(w) == 1
 
 
 def test_iterability_axes_argument():

lib/matplotlib/tests/test_ticker.py

@@ -97,6 +97,7 @@ def test_NullLocator_set_params():
     """
     loc = mticker.NullLocator()
     with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
         loc.set_params()
         nose.tools.assert_equal(len(w), 1)