setuptools test 使用 unittest disc

在使用 setuptools 来制作python包的安装程序时，支持使用以下命令来运行测试用例

python setup.py test

但默认情况下是使用 setuptools.command.test:ScanningLoader 来加载测试用例
如果要支持使用 unittest discover 来运行测试用例，需要做一些定制
参考这里的讨论
http://stackoverflow.com/questions/17001010/how-to-run-unittest-discover-from-python-setup-py-test
https://pytest.org/latest/goodpractises.html

from setuptools.command.test import test
def discover_and_run_tests():
    import os
        import sys
        import unittest
 
    # get setup.py directory
    setup_file = sys.modules['__main__'].__file__
    setup_dir = os.path.abspath(os.path.dirname(setup_file))
 
    # use the default shared TestLoader instance
    test_loader = unittest.defaultTestLoader
 
    # use the basic test runner that outputs to sys.stderr
    test_runner = unittest.TextTestRunner()
 
    # automatically discover all tests
    # NOTE: only works for python 2.7 and later
    test_suite = test_loader.discover(setup_dir)
 
    # run the test suite
    test_runner.run(test_suite)
 
class DiscoverTest(test):
    def finalize_options(self):
        test.finalize_options(self)
        self.test_args = []
        self.test_suite = True
 
    def run_tests(self):
        discover_and_run_tests()
 
setup(
....
    cmdclass={'test': DiscoverTest},
....
)