More cleanup and updating of tests

Clean up setup_test and add a teardown_test method

Implement new setup/teardown in novice tests

Fix warning handling in pil_plugin

Update rank tests

skimage/_shared/testing.py

@@ -179,14 +179,27 @@ def mono_check(plugin, fmt='png'):
 
 
 def setup_test():
-    warnings.simplefilter('error')
-    with all_warnings():
-       from scipy import signal, ndimage, special, optimize, linalg
-       from scipy.io import loadmat
-       from skimage import filter, viewer, data
-       data.moon()
-    if os.environ.get('TRAVIS_PYTHON_VERSION', None) == '2.7':
-        warnings.simplefilter('default') 
+    """Default package level setup routine for skimage tests.
+
+    Import packages known to raise errors, and then
+    force warnings to raise errors. 
+    """
+    warnings.simplefilter('default')
+    from scipy import signal, ndimage, special, optimize, linalg
+    from scipy.io import loadmat
+    from skimage import filter, viewer, data
+    # trigger PIL warnings
+    data.moon()
+    warnings.simplefilter('error') 
+
+
+def teardown_test():
+    """Default package level teardown routine for skimage tests.
+
+    Restore warnings to default behavior
+    """
+    warnings.simplefilter('default')
+
 
 if __name__ == '__main__':
     color_check('pil')

skimage/filters/rank/tests/__init__.py

@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()

skimage/filters/rank/tests/test_rank.py

@@ -7,18 +7,15 @@ from skimage import img_as_ubyte, img_as_float
 from skimage import data, util, morphology
 from skimage.morphology import cmorph, disk
 from skimage.filters import rank
-from skimage._shared.utils import all_warnings
-
-np.random.seed(0)
+from skimage._shared._warnings import expected_warnings
 
 
 def test_all():
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss', 'non-integer']):
         check_all()
 
 
 def check_all():
-    np.random.seed(0)
     image = np.random.rand(25, 25)
     selem = morphology.disk(1)
     refs = np.load(os.path.join(skimage.data_dir, "rank_filter_tests.npz"))
@@ -158,7 +155,11 @@ def test_bitdepth():
 
     for i in range(5):
         image = np.ones((100, 100), dtype=np.uint16) * 255 * 2 ** i
-        with all_warnings():  # bit depth
+        if i > 3:
+          expected = ["Bitdepth of"]
+        else:
+          expected = []
+        with expected_warnings(expected):
             rank.mean_percentile(image=image, selem=elem, mask=mask,
                                out=out, shift_x=0, shift_y=0, p0=.1, p1=.9)
 
@@ -269,7 +270,7 @@ def test_compare_ubyte_vs_float():
     for method in methods:
         func = getattr(rank, method)
         out_u = func(image_uint, disk(3))
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             out_f = func(image_float, disk(3))
         assert_equal(out_u, out_f)
 
@@ -282,9 +283,8 @@ def test_compare_8bit_unsigned_vs_signed():
     image = img_as_ubyte(data.camera())
     image[image > 127] = 0
     image_s = image.astype(np.int8)
-    with all_warnings():  # precision loss
+    with expected_warnings(['sign loss', 'precision loss']):
         image_u = img_as_ubyte(image_s)
-
         assert_equal(image_u, img_as_ubyte(image_s))
 
     methods = ['autolevel', 'bottomhat', 'equalize', 'gradient', 'maximum',
@@ -294,7 +294,7 @@ def test_compare_8bit_unsigned_vs_signed():
     for method in methods:
         func = getattr(rank, method)
 
-        with all_warnings():  # sign loss
+        with expected_warnings(['sign loss', 'precision loss']):
             out_u = func(image_u, disk(3))
             out_s = func(image_s, disk(3))
         assert_equal(out_u, out_s)
@@ -486,11 +486,11 @@ def test_entropy():
     selem = np.ones((64, 64), dtype=np.uint8)
     data = np.tile(
         np.reshape(np.arange(4096), (64, 64)), (2, 2)).astype(np.uint16)
-    with all_warnings():  # bitdepth
+    with expected_warnings(['Bitdepth of 11']):
         assert(np.max(rank.entropy(data, selem)) == 12)
 
     # make sure output is of dtype double
-    with all_warnings():  # bitdepth
+    with expected_warnings(['Bitdepth of 11']): 
         out = rank.entropy(data, np.ones((16, 16), dtype=np.uint8))
     assert out.dtype == np.double
 
@@ -522,12 +522,15 @@ def test_16bit():
     for bitdepth in range(17):
         value = 2 ** bitdepth - 1
         image[10, 10] = value
-        with all_warnings():  # bitdepth
+        if bitdepth > 11:
+          expected = ['Bitdepth of %s' % (bitdepth - 1)]
+        else:
+          expected = []
+        with expected_warnings(expected):
             assert rank.minimum(image, selem)[10, 10] == 0
             assert rank.maximum(image, selem)[10, 10] == value
             assert rank.mean(image, selem)[10, 10] == int(value / selem.size)
 
-
 def test_bilateral():
     image = np.zeros((21, 21), dtype=np.uint16)
     selem = np.ones((3, 3), dtype=np.uint8)

skimage/filters/tests/__init__.py

@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()

skimage/io/_plugins/pil_plugin.py

@@ -7,7 +7,7 @@ from PIL import Image
 from skimage.util import img_as_ubyte, img_as_uint
 from skimage.external.tifffile import (
     imread as tif_imread, imsave as tif_imsave)
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 def imread(fname, dtype=None, img_num=None, **kwargs):
@@ -48,13 +48,13 @@ def imread(fname, dtype=None, img_num=None, **kwargs):
     im = Image.open(fname)
     try:
         # this will raise an IOError if the file is not readable
-        im.getdata()[0]
+        with expected_warnings(['unclosed file']):
+            im.getdata()[0]
     except IOError:
         site = "http://pillow.readthedocs.org/en/latest/installation.html#external-libraries"
         raise ValueError('Could not load "%s"\nPlease see documentation at: %s' % (fname, site))
     else:
-        with all_warnings():  # PIL resource warnings
-            return pil_to_ndarray(im, dtype=dtype, img_num=img_num)
+        return pil_to_ndarray(im, dtype=dtype, img_num=img_num)
 
 
 def pil_to_ndarray(im, dtype=None, img_num=None):

skimage/novice/tests/__init__.py

@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()