major refactoring of the control session/parser classes; restructured constants

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = asyncio-taskpool
-version = 0.3.0
+version = 0.3.2
 author = Daniil Fajnberg
 author_email = mail@daniil.fajnberg.de
 description = Dynamically manage pools of asyncio tasks

src/asyncio_taskpool/client.py

@@ -26,8 +26,8 @@ from abc import ABC, abstractmethod
 from asyncio.streams import StreamReader, StreamWriter, open_unix_connection
 from pathlib import Path
 
-from asyncio_taskpool import constants
-from asyncio_taskpool.types import ClientConnT
+from .constants import CLIENT_EXIT, CLIENT_INFO, SESSION_MSG_BYTES
+from .types import ClientConnT
 
 
 class ControlClient(ABC):
@@ -38,7 +38,7 @@ class ControlClient(ABC):
 
     @staticmethod
     def client_info() -> dict:
-        return {'width': shutil.get_terminal_size().columns}
+        return {CLIENT_INFO.TERMINAL_WIDTH: shutil.get_terminal_size().columns}
 
     def __init__(self, **conn_kwargs) -> None:
         self._conn_kwargs = conn_kwargs
@@ -48,17 +48,17 @@ class ControlClient(ABC):
         self._connected = True
         writer.write(json.dumps(self.client_info()).encode())
         await writer.drain()
-        print("Connected to", (await reader.read(constants.MSG_BYTES)).decode())
+        print("Connected to", (await reader.read(SESSION_MSG_BYTES)).decode())
 
     async def _interact(self, reader: StreamReader, writer: StreamWriter) -> None:
         try:
             msg = input("> ").strip().lower()
         except EOFError:
-            msg = constants.CLIENT_EXIT
+            msg = CLIENT_EXIT
         except KeyboardInterrupt:
             print()
             return
-        if msg == constants.CLIENT_EXIT:
+        if msg == CLIENT_EXIT:
             writer.close()
             self._connected = False
             return
@@ -69,7 +69,7 @@ class ControlClient(ABC):
             self._connected = False
             print(e, file=sys.stderr)
             return
-        print((await reader.read(constants.MSG_BYTES)).decode())
+        print((await reader.read(SESSION_MSG_BYTES)).decode())
 
     async def start(self):
         reader, writer = await self.open_connection(**self._conn_kwargs)

src/asyncio_taskpool/constants.py

@@ -20,13 +20,25 @@ Constants used by more than one module in the package.
 
 
 PACKAGE_NAME = 'asyncio_taskpool'
-MSG_BYTES = 1024000
-CMD = 'command'
-CMD_NAME = 'name'
-CMD_POOL_SIZE = 'pool-size'
-CMD_NUM_RUNNING = 'num-running'
-CMD_START = 'start'
-CMD_STOP = 'stop'
-CMD_STOP_ALL = 'stop-all'
-CMD_FUNC_NAME = 'func-name'
+
 CLIENT_EXIT = 'exit'
+
+SESSION_MSG_BYTES = 1024 * 100
+SESSION_PARSER_WRITER = 'session_writer'
+
+
+class CLIENT_INFO:
+    __slots__ = ()
+    TERMINAL_WIDTH = 'terminal_width'
+
+
+class CMD:
+    __slots__ = ()
+    CMD = 'command'
+    NAME = 'name'
+    POOL_SIZE = 'pool-size'
+    NUM_RUNNING = 'num-running'
+    START = 'start'
+    STOP = 'stop'
+    STOP_ALL = 'stop-all'
+    FUNC_NAME = 'func-name'

src/asyncio_taskpool/server.py

@@ -31,74 +31,121 @@ from typing import Optional, Union
 from .client import ControlClient, UnixControlClient
 from .pool import TaskPool, SimpleTaskPool
 from .session import ControlSession
+from .types import ConnectedCallbackT
 
 
 log = logging.getLogger(__name__)
 
 
 class ControlServer(ABC):  # TODO: Implement interface for normal TaskPool instances, not just SimpleTaskPool
+    """
+    Abstract base class for a task pool control server.
+
+    This class acts as a wrapper around an async server instance and initializes a `ControlSession` upon a client
+    connecting to it. The entire interface is defined within that session class.
+    """
     _client_class = ControlClient
 
     @classmethod
     @property
     def client_class_name(cls) -> str:
+        """Returns the name of the control client class matching the server class."""
         return cls._client_class.__name__
 
     @abstractmethod
-    async def get_server_instance(self, client_connected_cb, **kwargs) -> AbstractServer:
+    async def _get_server_instance(self, client_connected_cb: ConnectedCallbackT, **kwargs) -> AbstractServer:
+        """
+        Initializes, starts, and returns an async server instance (Unix or TCP type).
+
+        Args:
+            client_connected_cb:
+                The callback for when a client connects to the server (as per `asyncio.start_server` or
+                `asyncio.start_unix_server`); will always be the internal `_client_connected_cb` method.
+            **kwargs (optional):
+                Keyword arguments to pass into the function that starts the server.
+
+        Returns:
+            The running server object (a type of `asyncio.Server`).
+        """
         raise NotImplementedError
 
     @abstractmethod
-    def final_callback(self) -> None:
+    def _final_callback(self) -> None:
+        """The method to run after the server's `serve_forever` methods ends for whatever reason."""
         raise NotImplementedError
 
     def __init__(self, pool: Union[TaskPool, SimpleTaskPool], **server_kwargs) -> None:
+        """
+        Initializes by merely saving the internal attributes, but without starting the server yet.
+        The task pool must be passed here and can not be set/changed afterwards. This means a control server is always
+        tied to one specific task pool.
+
+        Args:
+            pool:
+                An instance of a `BaseTaskPool` subclass to tie the server to.
+            **server_kwargs (optional):
+                Keyword arguments that will be passed into the function that starts the server.
+        """
         self._pool: Union[TaskPool, SimpleTaskPool] = pool
         self._server_kwargs = server_kwargs
         self._server: Optional[AbstractServer] = None
 
-    def __str__(self) -> str:
-        return f"{self.__class__.__name__} for {self._pool}"
-
     @property
     def pool(self) -> Union[TaskPool, SimpleTaskPool]:
+        """Read-only property for accessing the task pool instance controlled by the server."""
         return self._pool
 
     def is_serving(self) -> bool:
+        """Wrapper around the `asyncio.Server.is_serving` method."""
         return self._server.is_serving()
 
     async def _client_connected_cb(self, reader: StreamReader, writer: StreamWriter) -> None:
+        """
+        The universal client callback that will be passed into the `_get_server_instance` method.
+        Instantiates a control session, performs the client handshake, and enters the session's `listen` loop.
+        """
         session = ControlSession(self, reader, writer)
         await session.client_handshake()
         await session.listen()
 
     async def _serve_forever(self) -> None:
+        """
+        To be run as an `asyncio.Task` by the following method.
+        Serves as a wrapper around the the `asyncio.Server.serve_forever` method that ensures that the `_final_callback`
+        method is called, when the former method ends for whatever reason.
+        """
         try:
             async with self._server:
                 await self._server.serve_forever()
         except CancelledError:
             log.debug("%s stopped", self.__class__.__name__)
         finally:
-            self.final_callback()
+            self._final_callback()
 
     async def serve_forever(self) -> Task:
+        """
+        This method actually starts the server and begins listening to client connections on the specified interface.
+        It should never block because the serving will be performed in a separate task.
+        """
         log.debug("Starting %s...", self.__class__.__name__)
-        self._server = await self.get_server_instance(self._client_connected_cb, **self._server_kwargs)
+        self._server = await self._get_server_instance(self._client_connected_cb, **self._server_kwargs)
         return create_task(self._serve_forever())
 
 
 class UnixControlServer(ControlServer):
+    """Task pool control server class that exposes a unix socket for control clients to connect to."""
     _client_class = UnixControlClient
 
     def __init__(self, pool: SimpleTaskPool, **server_kwargs) -> None:
         self._socket_path = Path(server_kwargs.pop('path'))
         super().__init__(pool, **server_kwargs)
 
-    async def get_server_instance(self, client_connected_cb, **kwargs) -> AbstractServer:
-        srv = await start_unix_server(client_connected_cb, self._socket_path, **kwargs)
+    async def _get_server_instance(self, client_connected_cb: ConnectedCallbackT, **kwargs) -> AbstractServer:
+        server = await start_unix_server(client_connected_cb, self._socket_path, **kwargs)
         log.debug("Opened socket '%s'", str(self._socket_path))
-        return srv
+        return server
 
-    def final_callback(self) -> None:
+    def _final_callback(self) -> None:
+        """Removes the unix socket on which the server was listening."""
         self._socket_path.unlink()
         log.debug("Removed socket '%s'", str(self._socket_path))

src/asyncio_taskpool/session.py

@@ -1,13 +1,14 @@
 import logging
 import json
-from argparse import ArgumentError, ArgumentParser, HelpFormatter, Namespace
+from argparse import ArgumentError, HelpFormatter, Namespace
 from asyncio.streams import StreamReader, StreamWriter
-from typing import Callable, Optional, Type, Union, TYPE_CHECKING
+from typing import Callable, Optional, Union, TYPE_CHECKING
 
-from . import constants
+from .constants import CMD, SESSION_PARSER_WRITER, SESSION_MSG_BYTES, CLIENT_INFO
 from .exceptions import HelpRequested
 from .helpers import get_first_doc_line, return_or_exception, tasks_str
 from .pool import TaskPool, SimpleTaskPool
+from .session_parser import CommandParser, NUM
 
 if TYPE_CHECKING:
     from .server import ControlServer
@@ -15,47 +16,6 @@ if TYPE_CHECKING:
 
 log = logging.getLogger(__name__)
 
-NUM = 'num'
-WIDTH = 'width'
-
-
-class CommandParser(ArgumentParser):
-    @staticmethod
-    def help_formatter_factory(terminal_width: int) -> Type[HelpFormatter]:
-        class ClientHelpFormatter(HelpFormatter):
-            def __init__(self, *args, **kwargs) -> None:
-                kwargs[WIDTH] = terminal_width
-                super().__init__(*args, **kwargs)
-        return ClientHelpFormatter
-
-    def __init__(self, *args, **kwargs) -> None:
-        parent: CommandParser = kwargs.pop('parent', None)
-        self._stream_writer: StreamWriter = parent.stream_writer if parent else kwargs.pop('writer')
-        self._terminal_width: int = parent.terminal_width if parent else kwargs.pop(WIDTH)
-        kwargs.setdefault('formatter_class', self.help_formatter_factory(self._terminal_width))
-        kwargs.setdefault('exit_on_error', False)
-        super().__init__(*args, **kwargs)
-
-    @property
-    def stream_writer(self) -> StreamWriter:
-        return self._stream_writer
-
-    @property
-    def terminal_width(self) -> int:
-        return self._terminal_width
-
-    def _print_message(self, message: str, *args, **kwargs) -> None:
-        if message:
-            self.stream_writer.write(message.encode())
-
-    def exit(self, status: int = 0, message: str = None) -> None:
-        if message:
-            self._print_message(message)
-
-    def print_help(self, file=None) -> None:
-        super().print_help(file)
-        raise HelpRequested
-
 
 class ControlSession:
     def __init__(self, server: 'ControlServer', reader: StreamReader, writer: StreamWriter) -> None:
@@ -65,86 +25,65 @@ class ControlSession:
         self._reader: StreamReader = reader
         self._writer: StreamWriter = writer
         self._parser: Optional[CommandParser] = None
+        self._subparsers = None
 
-    def _add_base_commands(self):
-        subparsers = self._parser.add_subparsers(title="Commands", dest=constants.CMD)
-        subparsers.add_parser(
-            constants.CMD_NAME,
-            prog=constants.CMD_NAME,
-            help=get_first_doc_line(self._pool.__class__.__str__),
-            parent=self._parser,
-        )
-        subparser_pool_size = subparsers.add_parser(
-            constants.CMD_POOL_SIZE,
-            prog=constants.CMD_POOL_SIZE,
-            help="Get/set the maximum number of tasks in the pool",
-            parent=self._parser,
-        )
-        subparser_pool_size.add_argument(
-            NUM,
-            nargs='?',
+    def _add_parser_command(self, name: str, prog: str = None, short_help: str = None, long_help: str = None, 
+                            **kwargs) -> CommandParser:
+        if prog is None:
+            prog = name
+        kwargs.setdefault('help', short_help or long_help)
+        kwargs.setdefault('description', long_help or short_help)
+        return self._subparsers.add_parser(name, prog=prog, parent=self._parser, **kwargs)
+
+    def _add_base_commands(self) -> None:
+        self._subparsers = self._parser.add_subparsers(title="Commands", dest=CMD.CMD)
+        self._add_parser_command(CMD.NAME, short_help=get_first_doc_line(self._pool.__class__.__str__))
+        self._add_parser_command(
+            CMD.POOL_SIZE, 
+            short_help="Get/set the maximum number of tasks in the pool.", 
+            formatter_class=HelpFormatter
+        ).add_optional_num_argument(
+            default=None,
             help=f"If passed a number: {get_first_doc_line(self._pool.__class__.pool_size.fset)} "
                  f"If omitted: {get_first_doc_line(self._pool.__class__.pool_size.fget)}"
         )
-        subparsers.add_parser(
-            constants.CMD_NUM_RUNNING,
-            help=get_first_doc_line(self._pool.__class__.num_running.fget),
-            parent=self._parser,
+        self._add_parser_command(
+            CMD.NUM_RUNNING, short_help=get_first_doc_line(self._pool.__class__.num_running.fget)
         )
-        return subparsers
 
-    def _add_simple_commands(self):
-        subparsers = self._add_base_commands()
-        subparser = subparsers.add_parser(
-            constants.CMD_START,
-            prog=constants.CMD_START,
-            help=get_first_doc_line(self._pool.__class__.start),
-            parent=self._parser,
+    def _add_simple_commands(self) -> None:
+        self._add_parser_command(
+            CMD.START, short_help=get_first_doc_line(self._pool.__class__.start)
+        ).add_optional_num_argument(
+            help="Number of tasks to start."
         )
-        subparser.add_argument(
-            NUM,
-            nargs='?',
-            type=int,
-            default=1,
-            help="Number of tasks to start. Defaults to 1."
+        self._add_parser_command(
+            CMD.STOP, short_help=get_first_doc_line(self._pool.__class__.stop)
+        ).add_optional_num_argument(
+            help="Number of tasks to stop."
         )
-        subparser = subparsers.add_parser(
-            constants.CMD_STOP,
-            prog=constants.CMD_STOP,
-            help=get_first_doc_line(self._pool.__class__.stop),
-            parent=self._parser,
-        )
-        subparser.add_argument(
-            NUM,
-            nargs='?',
-            type=int,
-            default=1,
-            help="Number of tasks to stop. Defaults to 1."
-        )
-        subparsers.add_parser(
-            constants.CMD_STOP_ALL,
-            prog=constants.CMD_STOP_ALL,
-            help=get_first_doc_line(self._pool.__class__.stop_all),
-            parent=self._parser,
-        )
-        subparsers.add_parser(
-            constants.CMD_FUNC_NAME,
-            prog=constants.CMD_FUNC_NAME,
-            help=get_first_doc_line(self._pool.__class__.func_name.fget),
-            parent=self._parser,
+        self._add_parser_command(CMD.STOP_ALL, short_help=get_first_doc_line(self._pool.__class__.stop_all))
+        self._add_parser_command(
+            CMD.FUNC_NAME, short_help=get_first_doc_line(self._pool.__class__.func_name.fget)
         )
 
     def _init_parser(self, client_terminal_width: int) -> None:
-        self._parser = CommandParser(prog='', writer=self._writer, width=client_terminal_width)
+        parser_kwargs = {
+            'prog': '',
+            SESSION_PARSER_WRITER: self._writer,
+            CLIENT_INFO.TERMINAL_WIDTH: client_terminal_width,
+        }
+        self._parser = CommandParser(**parser_kwargs)
+        self._add_base_commands()
         if isinstance(self._pool, TaskPool):
             pass  # TODO
         elif isinstance(self._pool, SimpleTaskPool):
             self._add_simple_commands()
 
     async def client_handshake(self) -> None:
-        client_info = json.loads((await self._reader.read(constants.MSG_BYTES)).decode().strip())
+        client_info = json.loads((await self._reader.read(SESSION_MSG_BYTES)).decode().strip())
         log.debug("%s connected", self._client_class_name)
-        self._init_parser(client_info[WIDTH])
+        self._init_parser(client_info[CLIENT_INFO.TERMINAL_WIDTH])
         self._writer.write(str(self._pool).encode())
         await self._writer.drain()
 
@@ -163,7 +102,7 @@ class ControlSession:
             await self._write_function_output(self._pool.__class__.pool_size.fget, self._pool)
         else:
             log.debug("%s requests setting pool size to %s", self._client_class_name, num)
-            await self._write_function_output(self._pool.__class__.pool_size.fset, self._pool, int(num))
+            await self._write_function_output(self._pool.__class__.pool_size.fset, self._pool, num)
 
     async def _cmd_num_running(self, **_kwargs) -> None:
         log.debug("%s requests number of running tasks", self._client_class_name)
@@ -189,7 +128,7 @@ class ControlSession:
 
     async def _execute_command(self, args: Namespace) -> None:
         args = vars(args)
-        cmd: str = args.pop(constants.CMD, None)
+        cmd: str = args.pop(CMD.CMD, None)
         if cmd is not None:
             method = getattr(self, f'_cmd_{cmd.replace("-", "_")}')
             await method(**args)
@@ -210,7 +149,7 @@ class ControlSession:
 
     async def listen(self) -> None:
         while self._control_server.is_serving():
-            msg = (await self._reader.read(constants.MSG_BYTES)).decode().strip()
+            msg = (await self._reader.read(SESSION_MSG_BYTES)).decode().strip()
             if not msg:
                 log.debug("%s disconnected", self._client_class_name)
                 break

src/asyncio_taskpool/session_parser.py

@@ -0,0 +1,60 @@
+from argparse import Action, ArgumentParser, ArgumentDefaultsHelpFormatter, HelpFormatter
+from asyncio.streams import StreamWriter
+from typing import Type, TypeVar
+
+from .constants import SESSION_PARSER_WRITER, CLIENT_INFO
+from .exceptions import HelpRequested
+
+
+FmtCls = TypeVar('FmtCls', bound=Type[HelpFormatter])
+FORMATTER_CLASS = 'formatter_class'
+NUM = 'num'
+
+
+class CommandParser(ArgumentParser):
+    @staticmethod
+    def help_formatter_factory(terminal_width: int, base_cls: FmtCls = None) -> FmtCls:
+        if base_cls is None:
+            base_cls = ArgumentDefaultsHelpFormatter
+
+        class ClientHelpFormatter(base_cls):
+            def __init__(self, *args, **kwargs) -> None:
+                kwargs['width'] = terminal_width
+                super().__init__(*args, **kwargs)
+        return ClientHelpFormatter
+
+    def __init__(self, *args, **kwargs) -> None:
+        parent: CommandParser = kwargs.pop('parent', None)
+        self._stream_writer: StreamWriter = parent.stream_writer if parent else kwargs.pop(SESSION_PARSER_WRITER)
+        self._terminal_width: int = parent.terminal_width if parent else kwargs.pop(CLIENT_INFO.TERMINAL_WIDTH)
+        kwargs[FORMATTER_CLASS] = self.help_formatter_factory(self._terminal_width, kwargs.get(FORMATTER_CLASS))
+        kwargs.setdefault('exit_on_error', False)
+        super().__init__(*args, **kwargs)
+
+    @property
+    def stream_writer(self) -> StreamWriter:
+        return self._stream_writer
+
+    @property
+    def terminal_width(self) -> int:
+        return self._terminal_width
+
+    def _print_message(self, message: str, *args, **kwargs) -> None:
+        if message:
+            self.stream_writer.write(message.encode())
+
+    def exit(self, status: int = 0, message: str = None) -> None:
+        if message:
+            self._print_message(message)
+
+    def print_help(self, file=None) -> None:
+        super().print_help(file)
+        raise HelpRequested
+
+    def add_optional_num_argument(self, *name_or_flags: str, **kwargs) -> Action:
+        if not name_or_flags:
+            name_or_flags = (NUM, )
+        kwargs.setdefault('nargs', '?')
+        kwargs.setdefault('default', 1)
+        kwargs.setdefault('type', int)
+        return self.add_argument(*name_or_flags, **kwargs)

src/asyncio_taskpool/types.py

@@ -34,4 +34,5 @@ CoroutineFunc = Callable[[...], Awaitable[Any]]
 EndCallbackT = Callable
 CancelCallbackT = Callable
 
+ConnectedCallbackT = Callable[[StreamReader, StreamWriter], Awaitable[None]]
 ClientConnT = Union[Tuple[StreamReader, StreamWriter], Tuple[None, None]]

tests/test_server.py

@@ -0,0 +1,143 @@
+import asyncio
+import logging
+from pathlib import Path
+from unittest import IsolatedAsyncioTestCase
+from unittest.mock import AsyncMock, MagicMock, patch
+
+from asyncio_taskpool import server
+from asyncio_taskpool.client import ControlClient, UnixControlClient
+
+
+FOO, BAR = 'foo', 'bar'
+
+
+class ControlServerTestCase(IsolatedAsyncioTestCase):
+    log_lvl: int
+
+    @classmethod
+    def setUpClass(cls) -> None:
+        cls.log_lvl = server.log.level
+        server.log.setLevel(999)
+
+    @classmethod
+    def tearDownClass(cls) -> None:
+        server.log.setLevel(cls.log_lvl)
+
+    def setUp(self) -> None:
+        self.abstract_patcher = patch('asyncio_taskpool.server.ControlServer.__abstractmethods__', set())
+        self.mock_abstract_methods = self.abstract_patcher.start()
+        self.mock_pool = MagicMock()
+        self.kwargs = {FOO: 123, BAR: 456}
+        self.server = server.ControlServer(pool=self.mock_pool, **self.kwargs)
+
+    def tearDown(self) -> None:
+        self.abstract_patcher.stop()
+
+    def test_client_class_name(self):
+        self.assertEqual(ControlClient.__name__, server.ControlServer.client_class_name)
+
+    async def test_abstract(self):
+        with self.assertRaises(NotImplementedError):
+            args = [AsyncMock()]
+            await self.server._get_server_instance(*args)
+        with self.assertRaises(NotImplementedError):
+            self.server._final_callback()
+
+    def test_init(self):
+        self.assertEqual(self.mock_pool, self.server._pool)
+        self.assertEqual(self.kwargs, self.server._server_kwargs)
+        self.assertIsNone(self.server._server)
+
+    def test_pool(self):
+        self.assertEqual(self.mock_pool, self.server.pool)
+
+    def test_is_serving(self):
+        self.server._server = MagicMock(is_serving=MagicMock(return_value=FOO + BAR))
+        self.assertEqual(FOO + BAR, self.server.is_serving())
+
+    @patch.object(server, 'ControlSession')
+    async def test__client_connected_cb(self, mock_client_session_cls: MagicMock):
+        mock_client_handshake, mock_listen = AsyncMock(), AsyncMock()
+        mock_client_session_cls.return_value = MagicMock(client_handshake=mock_client_handshake, listen=mock_listen)
+        mock_reader, mock_writer = MagicMock(), MagicMock()
+        self.assertIsNone(await self.server._client_connected_cb(mock_reader, mock_writer))
+        mock_client_session_cls.assert_called_once_with(self.server, mock_reader, mock_writer)
+        mock_client_handshake.assert_awaited_once_with()
+        mock_listen.assert_awaited_once_with()
+
+    @patch.object(server.ControlServer, '_final_callback')
+    async def test__serve_forever(self, mock__final_callback: MagicMock):
+        mock_aenter, mock_serve_forever = AsyncMock(), AsyncMock(side_effect=asyncio.CancelledError)
+        self.server._server = MagicMock(__aenter__=mock_aenter, serve_forever=mock_serve_forever)
+        with self.assertLogs(server.log, logging.DEBUG):
+            self.assertIsNone(await self.server._serve_forever())
+        mock_aenter.assert_awaited_once_with()
+        mock_serve_forever.assert_awaited_once_with()
+        mock__final_callback.assert_called_once_with()
+
+        mock_aenter.reset_mock()
+        mock_serve_forever.reset_mock(side_effect=True)
+        mock__final_callback.reset_mock()
+
+        self.assertIsNone(await self.server._serve_forever())
+        mock_aenter.assert_awaited_once_with()
+        mock_serve_forever.assert_awaited_once_with()
+        mock__final_callback.assert_called_once_with()
+
+    @patch.object(server, 'create_task')
+    @patch.object(server.ControlServer, '_serve_forever', new_callable=MagicMock())
+    @patch.object(server.ControlServer, '_get_server_instance')
+    async def test_serve_forever(self, mock__get_server_instance: AsyncMock, mock__serve_forever: MagicMock,
+                                 mock_create_task: MagicMock):
+        mock__serve_forever.return_value = mock_awaitable = 'some_coroutine'
+        mock_create_task.return_value = expected_output = 12345
+        output = await self.server.serve_forever()
+        self.assertEqual(expected_output, output)
+        mock__get_server_instance.assert_awaited_once_with(self.server._client_connected_cb, **self.kwargs)
+        mock__serve_forever.assert_called_once_with()
+        mock_create_task.assert_called_once_with(mock_awaitable)
+
+
+class UnixControlServerTestCase(IsolatedAsyncioTestCase):
+    log_lvl: int
+
+    @classmethod
+    def setUpClass(cls) -> None:
+        cls.log_lvl = server.log.level
+        server.log.setLevel(999)
+
+    @classmethod
+    def tearDownClass(cls) -> None:
+        server.log.setLevel(cls.log_lvl)
+
+    def setUp(self) -> None:
+        self.base_init_patcher = patch.object(server.ControlServer, '__init__')
+        self.mock_base_init = self.base_init_patcher.start()
+        self.mock_pool = MagicMock()
+        self.path = '/tmp/asyncio_taskpool'
+        self.kwargs = {FOO: 123, BAR: 456}
+        self.server = server.UnixControlServer(pool=self.mock_pool, path=self.path, **self.kwargs)
+
+    def tearDown(self) -> None:
+        self.base_init_patcher.stop()
+
+    def test__client_class(self):
+        self.assertEqual(UnixControlClient, self.server._client_class)
+
+    def test_init(self):
+        self.assertEqual(Path(self.path), self.server._socket_path)
+        self.mock_base_init.assert_called_once_with(self.mock_pool, **self.kwargs)
+
+    @patch.object(server, 'start_unix_server')
+    async def test__get_server_instance(self, mock_start_unix_server: AsyncMock):
+        mock_start_unix_server.return_value = expected_output = 'totally_a_server'
+        mock_callback, mock_kwargs = MagicMock(), {'a': 1, 'b': 2}
+        args = [mock_callback]
+        output = await self.server._get_server_instance(*args, **mock_kwargs)
+        self.assertEqual(expected_output, output)
+        mock_start_unix_server.assert_called_once_with(mock_callback, Path(self.path), **mock_kwargs)
+
+    def test__final_callback(self):
+        self.server._socket_path = MagicMock()
+        self.assertIsNone(self.server._final_callback())
+        self.server._socket_path.unlink.assert_called_once_with()