Replace nose with pytest (#836)

* Use pytest instead of nose

* Remove nose dependencies

* "setup.py test" is deprecated

* More removal of nose usage

* Update to pytest

* Make ipv6 tests use pytest

* Make pytest happier with the name

* Upgrade coverage.py which seems to help with the 3.11 errors

* Link to doctests issue

* Switch to name that pytest will detect as being a test module.

* Expose tests to pytest

* Fix style

---------

Co-authored-by: Itamar Turner-Trauring <itamar@pythonspeed.com>

Author: itamarst

doc/testing.rst

@@ -1,25 +1,13 @@
 Testing Eventlet
 ================
 
-Eventlet is tested using `Nose <http://somethingaboutorange.com/mrl/projects/nose/>`_.  To run tests, simply install nose, and then, in the eventlet tree, do:
+Eventlet is tested using `Pytest <https://pytest/>`_.  To run tests, simply install pytest, and then, in the eventlet tree, do:
 
 .. code-block:: sh
 
-  $ python setup.py test
+  $ pytest
 
-If you want access to all the nose plugins via command line, you can run:
-
-.. code-block:: sh
-
-  $ python setup.py nosetests
-
-Lastly, you can just use nose directly if you want:
-
-.. code-block:: sh
-
-  $ nosetests
-
-That's it!  The output from running nose is the same as unittest's output, if the entire directory was one big test file.
+That's it!
 
 Many tests are skipped based on environmental factors; for example, it makes no sense to test kqueue-specific functionality when your OS does not support it.  These are printed as S's during execution, and in the summary printed after the tests run it will tell you how many were skipped.
 
@@ -30,9 +18,9 @@ To run the doctests included in many of the eventlet modules, use this command:
 
 .. code-block :: sh
 
-  $ nosetests --with-doctest eventlet/*.py
+  $ pytest --doctest-modules eventlet/
 
-Currently there are 16 doctests.
+The doctests currently `do not pass <https://github.com/eventlet/eventlet/issues/837>`_.
 
 
 Testing Eventlet Hubs
@@ -42,7 +30,7 @@ When you run the tests, Eventlet will use the most appropriate hub for the curre
 
 .. code-block:: sh
 
- $ EVENTLET_HUB=epolls nosetests
+ $ EVENTLET_HUB=epolls pytest
 
 See :ref:`understanding_hubs` for the full list of hubs.
 
@@ -62,11 +50,11 @@ If you are writing a test that involves a client connecting to a spawned server,
 Coverage
 --------
 
-Coverage.py is an awesome tool for evaluating how much code was exercised by unit tests.  Nose supports it if both are installed, so it's easy to generate coverage reports for eventlet.  Here's how:
+Coverage.py is an awesome tool for evaluating how much code was exercised by unit tests.  pytest supports it pytest-cov is installed, so it's easy to generate coverage reports for eventlet.  Here's how:
 
 .. code-block:: sh
 
- nosetests --with-coverage --cover-package=eventlet
+ pytest --cov=eventlet
 
 After running the tests to completion, this will emit a huge wodge of module names and line numbers.  For some reason, the ``--cover-inclusive`` option breaks everything rather than serving its purpose of limiting the coverage to the local files, so don't use that.
 

setup.py

@@ -31,7 +31,6 @@
             'README.rst'
         )
     ).read(),
-    test_suite='nose.collector',
     classifiers=[
         "Development Status :: 4 - Beta",
         "Intended Audience :: Developers",

tests/README

@@ -1,7 +1,4 @@
-The tests are intended to be run using Nose.  
-http://somethingaboutorange.com/mrl/projects/nose/
+The tests are intended to be run using pytest.
 
-To run tests, simply install nose, and then, in the eventlet tree, do:
-   $ nosetests
-
-That's it!  Its output is the same as unittest's output.  It tends to emit a lot of tracebacks from various poorly-behaving tests, but they still (generally) pass.
+To run tests, simply install pytest, and then, in the eventlet tree, do:
+   $ pytest

tests/__init__.py

@@ -20,7 +20,7 @@
 import unittest
 import warnings
 
-from nose.plugins.skip import SkipTest
+from unittest import SkipTest
 
 import eventlet
 from eventlet import tpool
@@ -213,7 +213,6 @@ def assert_less_than_equal(self, a, b, msg=None):
 def check_idle_cpu_usage(duration, allowed_part):
     if resource is None:
         # TODO: use https://code.google.com/p/psutil/
-        from nose.plugins.skip import SkipTest
         raise SkipTest('CPU usage testing not supported (`import resource` failed)')
 
     r1 = resource.getrusage(resource.RUSAGE_SELF)
@@ -392,18 +391,6 @@ def capture_stderr():
 private_key_file = os.path.join(os.path.dirname(__file__), 'test_server.key')
 
 
-def test_run_python_timeout():
-    output = run_python('', args=('-c', 'import time; time.sleep(0.5)'), timeout=0.1)
-    assert output.endswith(b'FAIL - timed out')
-
-
-def test_run_python_pythonpath_extend():
-    code = '''import os, sys ; print('\\n'.join(sys.path))'''
-    output = run_python('', args=('-c', code), pythonpath_extend=('dira', 'dirb'))
-    assert b'/dira\n' in output
-    assert b'/dirb\n' in output
-
-
 @contextlib.contextmanager
 def dns_tcp_server(ip_to_give, request_count=1):
     state = [0]  # request count storage writable by thread

tests/dagpool_test.py

@@ -5,14 +5,21 @@
 @brief  Test DAGPool class
 """
 
-from nose.tools import *
 import eventlet
 from eventlet.dagpool import DAGPool, Collision, PropagateError
 import six
 from contextlib import contextmanager
 import itertools
 
 
+def assert_equals(a, b):
+    """Backwards compatibility so we don't have to touch a bunch of tests."""
+    assert a == b
+
+
+assert_equal = assert_equals
+
+
 # Not all versions of nose.tools.assert_raises() support the usage in this
 # module, but it's straightforward enough to code that explicitly.
 @contextmanager
@@ -375,7 +382,7 @@ def test_spawn_multiple():
                   dict(a=1, b=2, c=3,
                        d="dval", e="eval", f="fval", g="gval", h="hval"))
     assert_equals(pool.running(), 0)
-    assert_false(pool.running_keys())
+    assert not pool.running_keys()
     assert_equals(pool.waiting(), 0)
     assert_equals(pool.waiting_for("h"), set())
 

tests/greenio_test.py

@@ -9,8 +9,6 @@
 import sys
 import tempfile
 
-from nose.tools import eq_
-
 import eventlet
 from eventlet import event, greenio, debug
 from eventlet.hubs import get_hub
@@ -39,7 +37,7 @@ def expect_socket_timeout(function, *args):
         raise AssertionError("socket.timeout not raised")
     except socket.timeout as e:
         assert hasattr(e, 'args')
-        eq_(e.args[0], 'timed out')
+        assert e.args[0] == 'timed out'
 
 
 def min_buf_size():
@@ -672,8 +670,8 @@ def test_datagram_socket_operations_work(self):
         sender.sendto(b'second', 0, address)
 
         sender_address = ('127.0.0.1', sender.getsockname()[1])
-        eq_(receiver.recvfrom(1024), (b'first', sender_address))
-        eq_(receiver.recvfrom(1024), (b'second', sender_address))
+        assert receiver.recvfrom(1024) == (b'first', sender_address)
+        assert receiver.recvfrom(1024) == (b'second', sender_address)
 
 
 def test_get_fileno_of_a_socket_works():

tests/nosewrapper.py

@@ -245,7 +245,7 @@ def test_it(self):
 SOMETIMES = RuntimeError('I fail half the time')
 
 
-class TestTookTooLong(Exception):
+class TookTooLongToRunTest(Exception):
     pass
 
 

tests/pools_test.py

@@ -0,0 +1,15 @@
+"""Tests for the testing infrastructure."""
+
+from . import run_python
+
+
+def test_run_python_timeout():
+    output = run_python('', args=('-c', 'import time; time.sleep(0.5)'), timeout=0.1)
+    assert output.endswith(b'FAIL - timed out')
+
+
+def test_run_python_pythonpath_extend():
+    code = '''import os, sys ; print('\\n'.join(sys.path))'''
+    output = run_python('', args=('-c', code), pythonpath_extend=('dira', 'dirb'))
+    assert b'/dira\n' in output
+    assert b'/dirb\n' in output