use pytest to test warnings

Author: alimanfoo

requirements.txt

@@ -1,5 +1,6 @@
 asciitree
 nose
+pytest
 numpy
 fasteners
 numcodecs

zarr/tests/test_creation.py

@@ -9,10 +9,11 @@
 import numpy as np
 from nose.tools import eq_ as eq, assert_is_none, assert_is_instance, assert_raises
 from numpy.testing import assert_array_equal
+import pytest
 
 
-from zarr.creation import (array, empty, zeros, ones, full, open_array, empty_like, zeros_like,
-                           ones_like, full_like, open_like, create)
+from zarr.creation import (array, empty, zeros, ones, full, open_array, empty_like,
+                           zeros_like, ones_like, full_like, open_like, create)
 from zarr.sync import ThreadSynchronizer
 from zarr.core import Array
 from zarr.storage import DirectoryStore
@@ -23,8 +24,9 @@
 
 
 # needed for PY2/PY3 consistent behaviour
-warnings.resetwarnings()
-warnings.simplefilter('always')
+if PY2:  # pragma: py3 no cover
+    warnings.resetwarnings()
+    warnings.simplefilter('always')
 
 
 # something bcolz-like
@@ -438,8 +440,6 @@ def test_create():
 
 
 def test_compression_args():
-    warnings.resetwarnings()
-    warnings.simplefilter('always')
 
     z = create(100, compression='zlib', compression_opts=9)
     assert_is_instance(z, Array)
@@ -458,16 +458,12 @@ def test_compression_args():
     eq('zlib', z.compressor.codec_id)
     eq(9, z.compressor.level)
 
-    warnings.resetwarnings()
-    warnings.simplefilter('error')
-    with assert_raises(UserWarning):
+    with pytest.warns(UserWarning):
         # 'compressor' overrides 'compression'
         create(100, compressor=Zlib(9), compression='bz2', compression_opts=1)
-    with assert_raises(UserWarning):
+    with pytest.warns(UserWarning):
         # 'compressor' ignores 'compression_opts'
         create(100, compressor=Zlib(9), compression_opts=1)
-    warnings.resetwarnings()
-    warnings.simplefilter('always')
 
 
 def test_create_read_only():
@@ -485,8 +481,8 @@ def test_create_read_only():
     with assert_raises(PermissionError):
         z[:] = 0
 
-    # this is subtly different, but here we want to create an array with data, and then have it
-    # be read-only
+    # this is subtly different, but here we want to create an array with data, and then
+    # have it be read-only
     a = np.arange(100)
     z = array(a, read_only=True)
     assert_array_equal(a, z[...])

zarr/tests/test_hierarchy.py

@@ -15,6 +15,7 @@
 from nose.tools import (assert_raises, eq_ as eq, assert_is, assert_true,
                         assert_is_instance, assert_false, assert_is_none)
 from nose import SkipTest
+import pytest
 
 
 from zarr.storage import (DictStore, DirectoryStore, ZipStore, init_group, init_array,
@@ -31,8 +32,9 @@
 
 
 # needed for PY2/PY3 consistent behaviour
-warnings.resetwarnings()
-warnings.simplefilter('always')
+if PY2:  # pragma: py3 no cover
+    warnings.resetwarnings()
+    warnings.simplefilter('always')
 
 
 # noinspection PyStatementEffect
@@ -363,16 +365,8 @@ def test_create_errors(self):
         eq(42, d.fill_value)
 
         # h5py compatibility, ignore 'shuffle'
-        warnings.resetwarnings()
-        warnings.simplefilter('always')
-        d = g.create_dataset('y1', shape=100, chunks=10, shuffle=True)
-        assert not hasattr(d, 'shuffle')
-        warnings.resetwarnings()
-        warnings.simplefilter('error')
-        with assert_raises(UserWarning):
-            g.create_dataset('y2', shape=100, chunks=10, shuffle=True)
-        warnings.resetwarnings()
-        warnings.simplefilter('always')
+        with pytest.warns(UserWarning, match="ignoring keyword argument 'shuffle'"):
+            g.create_dataset('y', shape=100, chunks=10, shuffle=True)
 
         # read-only
         g = self.create_group(read_only=True)
@@ -406,6 +400,7 @@ def test_create_overwrite(self):
                 # overwrite array with group
                 d = getattr(g, method_name)('foo/bar', shape=400, chunks=40,
                                             overwrite=True)
+                eq((400,), d.shape)
                 assert_is_instance(g['foo'], Group)
         except NotImplementedError:
             pass
@@ -1069,6 +1064,7 @@ def test_group_completions():
 def test_group_key_completions():
     g = group()
     d = dir(g)
+    # noinspection PyProtectedMember
     k = g._ipython_key_completions_()
 
     # none of these names should be an attribute
@@ -1103,6 +1099,7 @@ def test_group_key_completions():
     g.zeros('asdf;', shape=100)
 
     d = dir(g)
+    # noinspection PyProtectedMember
     k = g._ipython_key_completions_()
 
     assert 'foo' in d