def test_read_all_from_pipe_reader(self):
        # See asyncio issue 168.  This test is derived from the example
        # subprocess_attach_read_pipe.py, but we configure the
        # StreamReader's limit so that twice it is less than the size
        # of the data writter.  Also we must explicitly attach a child
        # watcher to the event loop.

        code = """\
import os, sys
fd = int(sys.argv[1])
os.write(fd, b'data')
os.close(fd)
"""
        rfd, wfd = os.pipe()
        args = [sys.executable, '-c', code, str(wfd)]

        pipe = open(rfd, 'rb', 0)
        reader = asyncio.StreamReader(loop=self.loop, limit=1)
        protocol = asyncio.StreamReaderProtocol(reader, loop=self.loop)
        transport, _ = self.loop.run_until_complete(
            self.loop.connect_read_pipe(lambda: protocol, pipe))

        watcher = asyncio.SafeChildWatcher()
        watcher.attach_loop(self.loop)
        try:
            asyncio.set_child_watcher(watcher)
            create = asyncio.create_subprocess_exec(*args,
                                                    pass_fds={wfd},
                                                    loop=self.loop)
            proc = self.loop.run_until_complete(create)
            self.loop.run_until_complete(proc.wait())
        finally:
            asyncio.set_child_watcher(None)

        os.close(wfd)
        data = self.loop.run_until_complete(reader.read(-1))
        self.assertEqual(data, b'data') 

def setUp(self):
            super().setUp()
            watcher = asyncio.SafeChildWatcher()
            watcher.attach_loop(self.loop)
            asyncio.set_child_watcher(watcher) 

def tearDown(self):
            asyncio.set_child_watcher(None)
            super().tearDown() 

def test_event_loop_policy(self):
        policy = asyncio.AbstractEventLoopPolicy()
        self.assertRaises(NotImplementedError, policy.get_event_loop)
        self.assertRaises(NotImplementedError, policy.set_event_loop, object())
        self.assertRaises(NotImplementedError, policy.new_event_loop)
        self.assertRaises(NotImplementedError, policy.get_child_watcher)
        self.assertRaises(NotImplementedError, policy.set_child_watcher,
                          object()) 

def main(cls, loop=None, argv=sys.argv):
        """
        Runs cli commands in asyncio loop and outputs in appropriate format
        """
        if loop is None:
            loop = asyncio.get_event_loop()
            # In Python 3.8 ThreadedChildWatcher becomes the default which
            # should work fine for us. However, in Python 3.7 SafeChildWatcher
            # is the default and may cause BlockingIOErrors when many
            # subprocesses are created
            # https://docs.python.org/3/library/asyncio-policy.html#asyncio.FastChildWatcher
            if (
                sys.version_info.major == 3
                and sys.version_info.minor == 7
                and sys.platform != "win32"
            ):
                watcher = asyncio.FastChildWatcher()
                asyncio.set_child_watcher(watcher)
                watcher.attach_loop(loop)
        result = None
        try:
            result = loop.run_until_complete(cls._main(*argv[1:]))
        except KeyboardInterrupt:  # pragma: no cover
            pass  # pragma: no cover
        loop.run_until_complete(loop.shutdown_asyncgens())
        loop.close() 

def test_read_all_from_pipe_reader(self):
        # See asyncio issue 168.  This test is derived from the example
        # subprocess_attach_read_pipe.py, but we configure the
        # StreamReader's limit so that twice it is less than the size
        # of the data writter.  Also we must explicitly attach a child
        # watcher to the event loop.

        code = """\
import os, sys
fd = int(sys.argv[1])
os.write(fd, b'data')
os.close(fd)
"""
        rfd, wfd = os.pipe()
        args = [sys.executable, '-c', code, str(wfd)]

        pipe = open(rfd, 'rb', 0)
        reader = asyncio.StreamReader(loop=self.loop, limit=1)
        protocol = asyncio.StreamReaderProtocol(reader, loop=self.loop)
        transport, _ = self.loop.run_until_complete(
            self.loop.connect_read_pipe(lambda: protocol, pipe))

        watcher = asyncio.SafeChildWatcher()
        watcher.attach_loop(self.loop)
        try:
            asyncio.set_child_watcher(watcher)
            create = asyncio.create_subprocess_exec(*args,
                                                    pass_fds={wfd},
                                                    loop=self.loop)
            proc = self.loop.run_until_complete(create)
            self.loop.run_until_complete(proc.wait())
        finally:
            asyncio.set_child_watcher(None)

        os.close(wfd)
        data = self.loop.run_until_complete(reader.read(-1))
        self.assertEqual(data, b'data') 

def setUp(self):
            super().setUp()
            watcher = asyncio.SafeChildWatcher()
            watcher.attach_loop(self.loop)
            asyncio.set_child_watcher(watcher) 

def tearDown(self):
            asyncio.set_child_watcher(None)
            super().tearDown() 

def test_event_loop_policy(self):
        policy = asyncio.AbstractEventLoopPolicy()
        self.assertRaises(NotImplementedError, policy.get_event_loop)
        self.assertRaises(NotImplementedError, policy.set_event_loop, object())
        self.assertRaises(NotImplementedError, policy.new_event_loop)
        self.assertRaises(NotImplementedError, policy.get_child_watcher)
        self.assertRaises(NotImplementedError, policy.set_child_watcher,
                          object()) 

def test_read_all_from_pipe_reader(self):
        # See Tulip issue 168.  This test is derived from the example
        # subprocess_attach_read_pipe.py, but we configure the
        # StreamReader's limit so that twice it is less than the size
        # of the data writter.  Also we must explicitly attach a child
        # watcher to the event loop.

        code = """\
import os, sys
fd = int(sys.argv[1])
os.write(fd, b'data')
os.close(fd)
"""
        rfd, wfd = os.pipe()
        args = [sys.executable, '-c', code, str(wfd)]

        pipe = open(rfd, 'rb', 0)
        reader = asyncio.StreamReader(loop=self.loop, limit=1)
        protocol = asyncio.StreamReaderProtocol(reader, loop=self.loop)
        transport, _ = self.loop.run_until_complete(
            self.loop.connect_read_pipe(lambda: protocol, pipe))

        watcher = asyncio.SafeChildWatcher()
        watcher.attach_loop(self.loop)
        try:
            asyncio.set_child_watcher(watcher)
            create = asyncio.create_subprocess_exec(*args,
                                                    pass_fds={wfd},
                                                    loop=self.loop)
            proc = self.loop.run_until_complete(create)
            self.loop.run_until_complete(proc.wait())
        finally:
            asyncio.set_child_watcher(None)

        os.close(wfd)
        data = self.loop.run_until_complete(reader.read(-1))
        self.assertEqual(data, b'data') 

def setUp(self):
            super().setUp()
            watcher = asyncio.SafeChildWatcher()
            watcher.attach_loop(self.loop)
            asyncio.set_child_watcher(watcher) 

def tearDown(self):
            asyncio.set_child_watcher(None)
            super().tearDown() 

def test_event_loop_policy(self):
        policy = asyncio.AbstractEventLoopPolicy()
        self.assertRaises(NotImplementedError, policy.get_event_loop)
        self.assertRaises(NotImplementedError, policy.set_event_loop, object())
        self.assertRaises(NotImplementedError, policy.new_event_loop)
        self.assertRaises(NotImplementedError, policy.get_child_watcher)
        self.assertRaises(NotImplementedError, policy.set_child_watcher,
                          object()) 

def test_read_all_from_pipe_reader(self):
        # See asyncio issue 168.  This test is derived from the example
        # subprocess_attach_read_pipe.py, but we configure the
        # StreamReader's limit so that twice it is less than the size
        # of the data writter.  Also we must explicitly attach a child
        # watcher to the event loop.

        code = """\
import os, sys
fd = int(sys.argv[1])
os.write(fd, b'data')
os.close(fd)
"""
        rfd, wfd = os.pipe()
        args = [sys.executable, '-c', code, str(wfd)]

        pipe = open(rfd, 'rb', 0)
        reader = asyncio.StreamReader(loop=self.loop, limit=1)
        protocol = asyncio.StreamReaderProtocol(reader, loop=self.loop)
        transport, _ = self.loop.run_until_complete(
            self.loop.connect_read_pipe(lambda: protocol, pipe))

        watcher = asyncio.SafeChildWatcher()
        watcher.attach_loop(self.loop)
        try:
            asyncio.set_child_watcher(watcher)
            create = asyncio.create_subprocess_exec(*args,
                                                    pass_fds={wfd},
                                                    loop=self.loop)
            proc = self.loop.run_until_complete(create)
            self.loop.run_until_complete(proc.wait())
        finally:
            asyncio.set_child_watcher(None)

        os.close(wfd)
        data = self.loop.run_until_complete(reader.read(-1))
        self.assertEqual(data, b'data') 

def setUp(self):
            super().setUp()
            watcher = asyncio.SafeChildWatcher()
            watcher.attach_loop(self.loop)
            asyncio.set_child_watcher(watcher) 

def tearDown(self):
            asyncio.set_child_watcher(None)
            super().tearDown() 

def test_event_loop_policy(self):
        policy = asyncio.AbstractEventLoopPolicy()
        self.assertRaises(NotImplementedError, policy.get_event_loop)
        self.assertRaises(NotImplementedError, policy.set_event_loop, object())
        self.assertRaises(NotImplementedError, policy.new_event_loop)
        self.assertRaises(NotImplementedError, policy.get_child_watcher)
        self.assertRaises(NotImplementedError, policy.set_child_watcher,
                          object()) 

def test_read_all_from_pipe_reader(self):
        # See asyncio issue 168.  This test is derived from the example
        # subprocess_attach_read_pipe.py, but we configure the
        # StreamReader's limit so that twice it is less than the size
        # of the data writter.  Also we must explicitly attach a child
        # watcher to the event loop.

        code = """\
import os, sys
fd = int(sys.argv[1])
os.write(fd, b'data')
os.close(fd)
"""
        rfd, wfd = os.pipe()
        args = [sys.executable, '-c', code, str(wfd)]

        pipe = open(rfd, 'rb', 0)
        reader = asyncio.StreamReader(loop=self.loop, limit=1)
        protocol = asyncio.StreamReaderProtocol(reader, loop=self.loop)
        transport, _ = self.loop.run_until_complete(
            self.loop.connect_read_pipe(lambda: protocol, pipe))

        watcher = asyncio.SafeChildWatcher()
        watcher.attach_loop(self.loop)
        try:
            asyncio.set_child_watcher(watcher)
            create = asyncio.create_subprocess_exec(*args,
                                                    pass_fds={wfd},
                                                    loop=self.loop)
            proc = self.loop.run_until_complete(create)
            self.loop.run_until_complete(proc.wait())
        finally:
            asyncio.set_child_watcher(None)

        os.close(wfd)
        data = self.loop.run_until_complete(reader.read(-1))
        self.assertEqual(data, b'data')