From 362c271ea101be04854ae4c33007fa7989e0e822 Mon Sep 17 00:00:00 2001
From: Nikita Kniazev <nok.raven@gmail.com>
Date: Tue, 12 Jul 2016 18:33:17 +0300
Subject: [PATCH] Prepare for cross-framework test suite

  - introduced `xfail(reason)` function
    - uses: `raise KnownFailureTest(msg)` -> `xfail(reason)`
    - same name and signature as in pytest

  - introduced `skip(reason)` function
    - uses: `raise SkipTest(msg)` -> `skip(reason)`
    - same name and signature as in pytest

  - introduced `skipif(condition, reason=None)` decorator
    - uses: replaces `def func(): if condition: skip()`
    - same name and signature as in pytest
    - can be used with functions, classes, and methods
    - supports string condition (evaluated at runtime)

  - moved nose related code to `testing.nose` submodule
    - plugins in `testing.nose.plugins` submodule
    - decorators implementation in `testing.nose.decorators`
      (interface is still in `testing.decorators`, implementation will
       have been chosen at runtime according to used test framework)

  - `matplotlib.test` function unifications
  - `tests.py` now uses `matplotlib.test()`
---
 lib/matplotlib/__init__.py                    | 65 ++--------------
 lib/matplotlib/testing/__init__.py            | 44 +++++++++++
 lib/matplotlib/testing/decorators.py          | 58 +++++----------
 lib/matplotlib/testing/exceptions.py          | 12 ---
 lib/matplotlib/testing/nose/__init__.py       | 70 ++++++++++++++++++
 lib/matplotlib/testing/nose/decorators.py     | 74 +++++++++++++++++++
 lib/matplotlib/testing/nose/exceptions.py     | 10 +++
 .../testing/nose/plugins/__init__.py          |  0
 .../plugins/knownfailure.py}                  |  6 +-
 .../testing/{ => nose/plugins}/performgc.py   |  0
 lib/matplotlib/tests/test_animation.py        | 14 ++--
 lib/matplotlib/tests/test_axes.py             |  7 +-
 lib/matplotlib/tests/test_backend_pgf.py      |  7 +-
 lib/matplotlib/tests/test_basic.py            | 46 +++++++++++-
 lib/matplotlib/tests/test_coding_standards.py |  7 +-
 lib/matplotlib/tests/test_image.py            |  1 -
 tests.py                                      | 33 ++-------
 17 files changed, 286 insertions(+), 168 deletions(-)
 create mode 100644 lib/matplotlib/testing/nose/__init__.py
 create mode 100644 lib/matplotlib/testing/nose/decorators.py
 create mode 100644 lib/matplotlib/testing/nose/exceptions.py
 create mode 100644 lib/matplotlib/testing/nose/plugins/__init__.py
 rename lib/matplotlib/testing/{noseclasses.py => nose/plugins/knownfailure.py} (90%)
 rename lib/matplotlib/testing/{ => nose/plugins}/performgc.py (100%)

diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
index 6f69f8f46165..aa701bfd3e0f 100644
--- a/lib/matplotlib/__init__.py
+++ b/lib/matplotlib/__init__.py
@@ -1398,7 +1398,7 @@ def use(arg, warn=True, force=False):
     if 'matplotlib.backends' in sys.modules:
         # Warn only if called with a different name
         if (rcParams['backend'] != name) and warn:
-            warnings.warn(_use_error_msg)
+            warnings.warn(_use_error_msg, stacklevel=2)
 
         # Unless we've been told to force it, just return
         if not force:
@@ -1580,70 +1580,17 @@ def _init_tests():
             )
         )
 
-    try:
-        import nose
-        try:
-            from unittest import mock
-        except:
-            import mock
-    except ImportError:
-        print("matplotlib.test requires nose and mock to run.")
-        raise
-
-
-def _get_extra_test_plugins():
-    from .testing.performgc import PerformGC
-    from .testing.noseclasses import KnownFailure
-    from nose.plugins import attrib
+    from .testing.nose import check_deps
+    check_deps()
 
-    return [PerformGC, KnownFailure, attrib.Plugin]
 
-
-def _get_nose_env():
-    env = {'NOSE_COVER_PACKAGE': 'matplotlib',
-           'NOSE_COVER_HTML': 1,
-           'NOSE_COVER_NO_PRINT': 1}
-    return env
-
-
-def test(verbosity=1, coverage=False):
+def test(verbosity=1, coverage=False, **kwargs):
     """run the matplotlib test suite"""
     _init_tests()
 
-    old_backend = rcParams['backend']
-    try:
-        use('agg')
-        import nose
-        import nose.plugins.builtin
-        from nose.plugins.manager import PluginManager
-        from nose.plugins import multiprocess
-
-        # store the old values before overriding
-        plugins = _get_extra_test_plugins()
-        plugins.extend([plugin for plugin in nose.plugins.builtin.plugins])
-
-        manager = PluginManager(plugins=[x() for x in plugins])
-        config = nose.config.Config(verbosity=verbosity, plugins=manager)
-
-        # Nose doesn't automatically instantiate all of the plugins in the
-        # child processes, so we have to provide the multiprocess plugin with
-        # a list.
-        multiprocess._instantiate_plugins = plugins
-
-        env = _get_nose_env()
-        if coverage:
-            env['NOSE_WITH_COVERAGE'] = 1
-
-        success = nose.run(
-            defaultTest=default_test_modules,
-            config=config,
-            env=env,
-        )
-    finally:
-        if old_backend.lower() != 'agg':
-            use(old_backend)
+    from .testing.nose import test as nose_test
+    return nose_test(verbosity, coverage, **kwargs)
 
-    return success
 
 test.__test__ = False  # nose: this function is not a test
 
diff --git a/lib/matplotlib/testing/__init__.py b/lib/matplotlib/testing/__init__.py
index 76de517f18a1..f47171652d10 100644
--- a/lib/matplotlib/testing/__init__.py
+++ b/lib/matplotlib/testing/__init__.py
@@ -1,6 +1,7 @@
 from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
 
+import inspect
 import warnings
 from contextlib import contextmanager
 
@@ -13,6 +14,49 @@ def _is_list_like(obj):
     return not is_string_like(obj) and iterable(obj)
 
 
+def xfail(msg=""):
+    """Explicitly fail an currently-executing test with the given message."""
+    from .nose import knownfail
+    knownfail(msg)
+
+
+def skip(msg=""):
+    """Skip an executing test with the given message."""
+    from nose import SkipTest
+    raise SkipTest(msg)
+
+
+# stolen from pytest
+def getrawcode(obj, trycall=True):
+    """Return code object for given function."""
+    try:
+        return obj.__code__
+    except AttributeError:
+        obj = getattr(obj, 'im_func', obj)
+        obj = getattr(obj, 'func_code', obj)
+        obj = getattr(obj, 'f_code', obj)
+        obj = getattr(obj, '__code__', obj)
+        if trycall and not hasattr(obj, 'co_firstlineno'):
+            if hasattr(obj, '__call__') and not inspect.isclass(obj):
+                x = getrawcode(obj.__call__, trycall=False)
+                if hasattr(x, 'co_firstlineno'):
+                    return x
+        return obj
+
+
+def copy_metadata(src_func, tgt_func):
+    """Replicates metadata of the function. Returns target function."""
+    tgt_func.__dict__ = src_func.__dict__
+    tgt_func.__doc__ = src_func.__doc__
+    tgt_func.__module__ = src_func.__module__
+    tgt_func.__name__ = src_func.__name__
+    if hasattr(src_func, '__qualname__'):
+        tgt_func.__qualname__ = src_func.__qualname__
+    if not hasattr(tgt_func, 'compat_co_firstlineno'):
+        tgt_func.compat_co_firstlineno = getrawcode(src_func).co_firstlineno
+    return tgt_func
+
+
 # stolen from pandas
 @contextmanager
 def assert_produces_warning(expected_warning=Warning, filter_level="always",
diff --git a/lib/matplotlib/testing/decorators.py b/lib/matplotlib/testing/decorators.py
index ffa17173c9f1..c79d6e5fbbc1 100644
--- a/lib/matplotlib/testing/decorators.py
+++ b/lib/matplotlib/testing/decorators.py
@@ -4,7 +4,6 @@
 import six
 
 import functools
-import gc
 import inspect
 import os
 import sys
@@ -12,9 +11,6 @@
 import warnings
 import unittest
 
-import nose
-import numpy as np
-
 import matplotlib as mpl
 import matplotlib.style
 import matplotlib.units
@@ -24,13 +20,23 @@
 from matplotlib import pyplot as plt
 from matplotlib import ft2font
 from matplotlib import rcParams
-from matplotlib.testing.noseclasses import KnownFailureTest, \
-     KnownFailureDidNotFailTest, ImageComparisonFailure
 from matplotlib.testing.compare import comparable_formats, compare_images, \
      make_test_filename
+from . import copy_metadata, skip, xfail
+from .exceptions import ImageComparisonFailure
+
+
+def skipif(condition, *args, **kwargs):
+    """Skip the given test function if eval(condition) results in a True
+    value.
+
+    Optionally specify a reason for better reporting.
+    """
+    from .nose.decorators import skipif
+    return skipif(condition, *args, **kwargs)
 
 
-def knownfailureif(fail_condition, msg=None, known_exception_class=None ):
+def knownfailureif(fail_condition, msg=None, known_exception_class=None):
     """
 
     Assume a will fail if *fail_condition* is True. *fail_condition*
@@ -42,32 +48,8 @@ def knownfailureif(fail_condition, msg=None, known_exception_class=None ):
     if the exception is an instance of this class. (Default = None)
 
     """
-    # based on numpy.testing.dec.knownfailureif
-    if msg is None:
-        msg = 'Test known to fail'
-    def known_fail_decorator(f):
-        # Local import to avoid a hard nose dependency and only incur the
-        # import time overhead at actual test-time.
-        import nose
-        def failer(*args, **kwargs):
-            try:
-                # Always run the test (to generate images).
-                result = f(*args, **kwargs)
-            except Exception as err:
-                if fail_condition:
-                    if known_exception_class is not None:
-                        if not isinstance(err,known_exception_class):
-                            # This is not the expected exception
-                            raise
-                    # (Keep the next ultra-long comment so in shows in console.)
-                    raise KnownFailureTest(msg) # An error here when running nose means that you don't have the matplotlib.testing.noseclasses:KnownFailure plugin in use.
-                else:
-                    raise
-            if fail_condition and fail_condition != 'indeterminate':
-                raise KnownFailureDidNotFailTest(msg)
-            return result
-        return nose.tools.make_decorator(f)(failer)
-    return known_fail_decorator
+    from .nose.decorators import knownfailureif
+    return knownfailureif(fail_condition, msg, known_exception_class)
 
 
 def _do_cleanup(original_units_registry, original_settings):
@@ -211,7 +193,7 @@ def remove_text(figure):
     def test(self):
         baseline_dir, result_dir = _image_directories(self._func)
         if self._style != 'classic':
-            raise KnownFailureTest('temporarily disabled until 2.0 tag')
+            xfail('temporarily disabled until 2.0 tag')
         for fignum, baseline in zip(plt.get_fignums(), self._baseline_images):
             for extension in self._extensions:
                 will_fail = not extension in comparable_formats()
@@ -263,13 +245,14 @@ def do_test():
                                 '(RMS %(rms).3f)'%err)
                     except ImageComparisonFailure:
                         if not check_freetype_version(self._freetype_version):
-                            raise KnownFailureTest(
+                            xfail(
                                 "Mismatched version of freetype.  Test requires '%s', you have '%s'" %
                                 (self._freetype_version, ft2font.__freetype_version__))
                         raise
 
                 yield (do_test,)
 
+
 def image_comparison(baseline_images=None, extensions=None, tol=0,
                      freetype_version=None, remove_text=False,
                      savefig_kwarg=None, style='classic'):
@@ -428,7 +411,7 @@ def backend_switcher(*args, **kwargs):
                 plt.switch_backend(prev_backend)
             return result
 
-        return nose.tools.make_decorator(func)(backend_switcher)
+        return copy_metadata(func, backend_switcher)
     return switch_backend_decorator
 
 
@@ -447,7 +430,6 @@ def skip_if_command_unavailable(cmd):
     try:
         check_output(cmd)
     except:
-        from nose import SkipTest
-        raise SkipTest('missing command: %s' % cmd[0])
+        skip('missing command: %s' % cmd[0])
 
     return lambda f: f
diff --git a/lib/matplotlib/testing/exceptions.py b/lib/matplotlib/testing/exceptions.py
index b549d89205ec..c39a39207747 100644
--- a/lib/matplotlib/testing/exceptions.py
+++ b/lib/matplotlib/testing/exceptions.py
@@ -1,15 +1,3 @@
-class KnownFailureTest(Exception):
-    """
-    Raise this exception to mark a test as a known failing test.
-    """
-
-
-class KnownFailureDidNotFailTest(Exception):
-    """
-    Raise this exception to mark a test should have failed but did not.
-    """
-
-
 class ImageComparisonFailure(AssertionError):
     """
     Raise this exception to mark a test as a comparison between two images.
diff --git a/lib/matplotlib/testing/nose/__init__.py b/lib/matplotlib/testing/nose/__init__.py
new file mode 100644
index 000000000000..df3ec0b23692
--- /dev/null
+++ b/lib/matplotlib/testing/nose/__init__.py
@@ -0,0 +1,70 @@
+from __future__ import (absolute_import, division, print_function,
+                        unicode_literals)
+
+
+def get_extra_test_plugins():
+    from .plugins.performgc import PerformGC
+    from .plugins.knownfailure import KnownFailure
+    from nose.plugins import attrib
+
+    return [PerformGC, KnownFailure, attrib.Plugin]
+
+
+def get_env():
+    env = {'NOSE_COVER_PACKAGE': 'matplotlib',
+           'NOSE_COVER_HTML': 1,
+           'NOSE_COVER_NO_PRINT': 1}
+    return env
+
+
+def check_deps():
+    try:
+        import nose
+        try:
+            from unittest import mock
+        except ImportError:
+            import mock
+    except ImportError:
+        print("matplotlib.test requires nose and mock to run.")
+        raise
+
+
+def test(verbosity=None, coverage=False, switch_backend_warn=True, **kwargs):
+    from ... import default_test_modules, get_backend, use
+
+    old_backend = get_backend()
+    try:
+        use('agg')
+        import nose
+        from nose.plugins import multiprocess
+
+        # Nose doesn't automatically instantiate all of the plugins in the
+        # child processes, so we have to provide the multiprocess plugin with
+        # a list.
+        extra_plugins = get_extra_test_plugins()
+        multiprocess._instantiate_plugins = extra_plugins
+
+        env = get_env()
+        if coverage:
+            env['NOSE_WITH_COVERAGE'] = 1
+
+        if verbosity is not None:
+            env['NOSE_VERBOSE'] = verbosity
+
+        success = nose.run(
+            addplugins=[plugin() for plugin in extra_plugins],
+            env=env,
+            defaultTest=default_test_modules,
+            **kwargs
+        )
+    finally:
+        if old_backend.lower() != 'agg':
+            use(old_backend, warn=switch_backend_warn)
+
+    return success
+
+
+def knownfail(msg):
+    from .exceptions import KnownFailureTest
+    # Keep the next ultra-long comment so it shows in console.
+    raise KnownFailureTest(msg)  # An error here when running nose means that you don't have the matplotlib.testing.nose.plugins:KnownFailure plugin in use.  # noqa
diff --git a/lib/matplotlib/testing/nose/decorators.py b/lib/matplotlib/testing/nose/decorators.py
new file mode 100644
index 000000000000..d6456b76424e
--- /dev/null
+++ b/lib/matplotlib/testing/nose/decorators.py
@@ -0,0 +1,74 @@
+from __future__ import (absolute_import, division, print_function,
+                        unicode_literals)
+
+import os
+import six
+import sys
+from .. import copy_metadata, skip
+from . import knownfail
+from .exceptions import KnownFailureDidNotFailTest
+
+
+def skipif(skip_condition, *args, **kwargs):
+    if isinstance(skip_condition, bool) and 'reason' not in kwargs:
+        raise ValueError("you need to specify reason=STRING "
+                         "when using booleans as conditions.")
+
+    def skip_decorator(func):
+        import inspect
+
+        def skipper(*_args, **_kwargs):
+            condition, msg = skip_condition, kwargs.get('reason')  # local copy
+            if isinstance(condition, six.string_types):
+                globs = {'os': os, 'sys': sys}
+                try:
+                    globs.update(func.__globals__)
+                except AttributeError:
+                    globs.update(func.func_globals)
+                if msg is None:
+                    msg = condition
+                condition = eval(condition, globs)
+            else:
+                condition = bool(condition)
+
+            if condition:
+                skip(msg)
+            else:
+                return func(*_args, **_kwargs)
+
+        if inspect.isclass(func):
+            setup = getattr(func, 'setup_class', classmethod(lambda _: None))
+            setup = skip_decorator(setup.__func__)
+            setup = setup.__get__(func)
+            setattr(func, 'setup_class', setup)
+            return func
+
+        return copy_metadata(func, skipper)
+
+    return skip_decorator
+
+
+def knownfailureif(fail_condition, msg=None, known_exception_class=None):
+    # based on numpy.testing.dec.knownfailureif
+    if msg is None:
+        msg = 'Test known to fail'
+
+    def known_fail_decorator(f):
+        def failer(*args, **kwargs):
+            try:
+                # Always run the test (to generate images).
+                result = f(*args, **kwargs)
+            except Exception as err:
+                if fail_condition:
+                    if known_exception_class is not None:
+                        if not isinstance(err, known_exception_class):
+                            # This is not the expected exception
+                            raise
+                    knownfail(msg)
+                else:
+                    raise
+            if fail_condition and fail_condition != 'indeterminate':
+                raise KnownFailureDidNotFailTest(msg)
+            return result
+        return copy_metadata(f, failer)
+    return known_fail_decorator
diff --git a/lib/matplotlib/testing/nose/exceptions.py b/lib/matplotlib/testing/nose/exceptions.py
new file mode 100644
index 000000000000..51fc6f782d78
--- /dev/null
+++ b/lib/matplotlib/testing/nose/exceptions.py
@@ -0,0 +1,10 @@
+class KnownFailureTest(Exception):
+    """
+    Raise this exception to mark a test as a known failing test.
+    """
+
+
+class KnownFailureDidNotFailTest(Exception):
+    """
+    Raise this exception to mark a test should have failed but did not.
+    """
diff --git a/lib/matplotlib/testing/nose/plugins/__init__.py b/lib/matplotlib/testing/nose/plugins/__init__.py
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/lib/matplotlib/testing/noseclasses.py b/lib/matplotlib/testing/nose/plugins/knownfailure.py
similarity index 90%
rename from lib/matplotlib/testing/noseclasses.py
rename to lib/matplotlib/testing/nose/plugins/knownfailure.py
index 8bcb09d28a29..3a5c86c35048 100644
--- a/lib/matplotlib/testing/noseclasses.py
+++ b/lib/matplotlib/testing/nose/plugins/knownfailure.py
@@ -1,13 +1,9 @@
 from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
 
-import six
-
 import os
 from nose.plugins.errorclass import ErrorClass, ErrorClassPlugin
-from matplotlib.testing.exceptions import (KnownFailureTest,
-                                           KnownFailureDidNotFailTest,
-                                           ImageComparisonFailure)
+from ..exceptions import KnownFailureTest
 
 
 class KnownFailure(ErrorClassPlugin):
diff --git a/lib/matplotlib/testing/performgc.py b/lib/matplotlib/testing/nose/plugins/performgc.py
similarity index 100%
rename from lib/matplotlib/testing/performgc.py
rename to lib/matplotlib/testing/nose/plugins/performgc.py
diff --git a/lib/matplotlib/tests/test_animation.py b/lib/matplotlib/tests/test_animation.py
index 7a63de9d640f..c6373584ce2d 100644
--- a/lib/matplotlib/tests/test_animation.py
+++ b/lib/matplotlib/tests/test_animation.py
@@ -8,14 +8,12 @@
 import tempfile
 import numpy as np
 from numpy.testing import assert_equal
-from nose import with_setup
 from nose.tools import assert_false, assert_true
 import matplotlib as mpl
 from matplotlib import pyplot as plt
 from matplotlib import animation
-from matplotlib.testing.noseclasses import KnownFailureTest
-from matplotlib.testing.decorators import cleanup
-from matplotlib.testing.decorators import CleanupTest
+from ..testing import xfail, skip
+from ..testing.decorators import cleanup
 
 
 class NullMovieWriter(animation.AbstractMovieWriter):
@@ -113,8 +111,7 @@ def test_save_animation_smoketest():
 @cleanup
 def check_save_animation(writer, extension='mp4'):
     if not animation.writers.is_available(writer):
-        raise KnownFailureTest("writer '%s' not available on this system"
-                               % writer)
+        skip("writer '%s' not available on this system" % writer)
     fig, ax = plt.subplots()
     line, = ax.plot([], [])
 
@@ -138,9 +135,8 @@ def animate(i):
     try:
         anim.save(F.name, fps=30, writer=writer, bitrate=500)
     except UnicodeDecodeError:
-        raise KnownFailureTest("There can be errors in the numpy " +
-                               "import stack, " +
-                               "see issues #1891 and #2679")
+        xfail("There can be errors in the numpy import stack, "
+              "see issues #1891 and #2679")
     finally:
         try:
             os.remove(F.name)
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
index 650b6078631a..c56dc621eb16 100644
--- a/lib/matplotlib/tests/test_axes.py
+++ b/lib/matplotlib/tests/test_axes.py
@@ -22,8 +22,7 @@
 import warnings
 
 import matplotlib
-from matplotlib.testing.decorators import image_comparison, cleanup
-from matplotlib.testing.noseclasses import KnownFailureTest
+from matplotlib.testing.decorators import image_comparison, cleanup, skipif
 import matplotlib.pyplot as plt
 import matplotlib.markers as mmarkers
 import matplotlib.patches as mpatches
@@ -87,10 +86,10 @@ def test_formatter_ticker():
     ax.autoscale_view()
 
 
+@skipif(LooseVersion(np.__version__) >= LooseVersion('1.11.0'),
+        reason="Fall out from a fixed numpy bug")
 @image_comparison(baseline_images=["formatter_large_small"])
 def test_formatter_large_small():
-    if LooseVersion(np.__version__) >= LooseVersion('1.11.0'):
-        raise KnownFailureTest("Fall out from a fixed numpy bug")
     # github issue #617, pull #619
     fig, ax = plt.subplots(1)
     x = [0.500000001, 0.500000002]
diff --git a/lib/matplotlib/tests/test_backend_pgf.py b/lib/matplotlib/tests/test_backend_pgf.py
index 36315d185262..a86f4de53226 100644
--- a/lib/matplotlib/tests/test_backend_pgf.py
+++ b/lib/matplotlib/tests/test_backend_pgf.py
@@ -2,13 +2,10 @@
 from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
 
-import six
-
 import os
 import shutil
 
 import numpy as np
-import nose
 from nose.plugins.skip import SkipTest
 
 import matplotlib as mpl
@@ -17,7 +14,7 @@
 from matplotlib.testing.compare import compare_images, ImageComparisonFailure
 from matplotlib.testing.decorators import (_image_directories, switch_backend,
                                            cleanup)
-from matplotlib.testing.noseclasses import KnownFailureTest
+from ..testing import xfail
 
 baseline_dir, result_dir = _image_directories(lambda: 'dummy func')
 
@@ -44,7 +41,7 @@ def check_for(texsystem):
 
 def compare_figure(fname, savefig_kwargs={}, tol=0):
     # TODO remove this before tagging 2.0
-    raise KnownFailureTest('temporarily disabled until 2.0 tag')
+    xfail('temporarily disabled until 2.0 tag')
     actual = os.path.join(result_dir, fname)
     plt.savefig(actual, **savefig_kwargs)
 
diff --git a/lib/matplotlib/tests/test_basic.py b/lib/matplotlib/tests/test_basic.py
index d5f23ba868aa..a5f3a33ba785 100644
--- a/lib/matplotlib/tests/test_basic.py
+++ b/lib/matplotlib/tests/test_basic.py
@@ -5,10 +5,17 @@
 
 from nose.tools import assert_equal
 
-from matplotlib.testing.decorators import knownfailureif
+from ..testing.decorators import knownfailureif, skipif
 from pylab import *
 
 
+SKIPIF_CONDITION = []
+
+
+def setup_module():
+    SKIPIF_CONDITION.append(None)
+
+
 def test_simple():
     assert_equal(1 + 1, 2)
 
@@ -19,8 +26,41 @@ def test_simple_knownfail():
     assert_equal(1 + 1, 3)
 
 
+@skipif(True, reason="skipif decorator test with bool condition passed")
+def test_skipif_bool():
+    assert False, "skipif decorator does not work with bool condition"
+
+
+@skipif('SKIPIF_CONDITION',
+        reason="skipif decorator test with string condition passed")
+def test_skipif_string():
+    assert False, "skipif decorator does not work with string condition"
+
+
+@skipif(True, reason="skipif decorator on class test passed")
+class Test_skipif_on_class(object):
+    def test(self):
+        assert False, "skipif decorator does not work on classes"
+
+
+class Test_skipif_on_method(object):
+    @skipif(True, reason="skipif decorator on method test passed")
+    def test(self):
+        assert False, "skipif decorator does not work on methods"
+
+
+@skipif(True, reason="skipif decorator on classmethod test passed")
+class Test_skipif_on_classmethod(object):
+    @classmethod
+    def setup_class(cls):
+        pass
+
+    def test(self):
+        assert False, "skipif decorator does not work on classmethods"
+
+
 def test_override_builtins():
-    ok_to_override = set([
+    ok_to_override = {
         '__name__',
         '__doc__',
         '__package__',
@@ -29,7 +69,7 @@ def test_override_builtins():
         'any',
         'all',
         'sum'
-    ])
+    }
 
     # We could use six.moves.builtins here, but that seems
     # to do a little more than just this.
diff --git a/lib/matplotlib/tests/test_coding_standards.py b/lib/matplotlib/tests/test_coding_standards.py
index f1aff0e589e1..6862ee2fed99 100644
--- a/lib/matplotlib/tests/test_coding_standards.py
+++ b/lib/matplotlib/tests/test_coding_standards.py
@@ -6,7 +6,7 @@
 
 from nose.tools import assert_equal
 from nose.plugins.skip import SkipTest
-from matplotlib.testing.noseclasses import KnownFailureTest
+from ..testing import xfail
 
 try:
     import pep8
@@ -256,9 +256,8 @@ def test_pep8_conformance_examples():
             fp, tail = os.path.split(fp)
 
     if mpldir is None:
-        raise KnownFailureTest("can not find the examples, set env "
-                               "MPL_REPO_DIR to point to the top-level path "
-                               "of the source tree")
+        xfail("can not find the examples, set env MPL_REPO_DIR to point "
+              "to the top-level path of the source tree")
 
     exdir = os.path.join(mpldir, 'examples')
     blacklist = ()
diff --git a/lib/matplotlib/tests/test_image.py b/lib/matplotlib/tests/test_image.py
index e06328440f2a..851f9cffb775 100644
--- a/lib/matplotlib/tests/test_image.py
+++ b/lib/matplotlib/tests/test_image.py
@@ -22,7 +22,6 @@
 from nose.tools import assert_raises
 from numpy.testing import (
     assert_array_equal, assert_array_almost_equal, assert_allclose)
-from matplotlib.testing.noseclasses import KnownFailureTest
 from copy import copy
 from numpy import ma
 import matplotlib.colors as colors
diff --git a/tests.py b/tests.py
index db19f5572772..d6c179ed31e5 100755
--- a/tests.py
+++ b/tests.py
@@ -9,43 +9,19 @@
 # See https://nose.readthedocs.org/ for a detailed description of
 # these options.
 
-import os
 import sys
-import time
 
-import matplotlib
-matplotlib.use('agg')
-
-import nose
-from matplotlib import default_test_modules
-
-
-def run(extra_args):
-    from nose.plugins import multiprocess
-
-    env = matplotlib._get_nose_env()
-
-    matplotlib._init_tests()
-
-    # Nose doesn't automatically instantiate all of the plugins in the
-    # child processes, so we have to provide the multiprocess plugin with
-    # a list.
-    plugins = matplotlib._get_extra_test_plugins()
-    multiprocess._instantiate_plugins = plugins
-
-    nose.main(addplugins=[x() for x in plugins],
-              defaultTest=default_test_modules,
-              argv=sys.argv + extra_args,
-              env=env)
 
 if __name__ == '__main__':
+    from matplotlib import default_test_modules, test
+
     extra_args = []
 
     if '--no-pep8' in sys.argv:
         default_test_modules.remove('matplotlib.tests.test_coding_standards')
         sys.argv.remove('--no-pep8')
     elif '--pep8' in sys.argv:
-        default_test_modules = ['matplotlib.tests.test_coding_standards']
+        default_test_modules[:] = ['matplotlib.tests.test_coding_standards']
         sys.argv.remove('--pep8')
     if '--no-network' in sys.argv:
         from matplotlib.testing import disable_internet
@@ -55,4 +31,5 @@ def run(extra_args):
 
     print('Python byte-compilation optimization level: %d' % sys.flags.optimize)
 
-    run(extra_args)
+    success = test(argv=sys.argv + extra_args, switch_backend_warn=False)
+    sys.exit(not success)