Add cast of message type in command interpreter (#75)

* #74 Add cast of message type in command interpreter

Co-authored-by: Garry O'Donnell <garry.o'donnell@diamond.ac.uk>

* Add type hint patch to command interpreter tests

Co-authored-by: Callum Forrester <29771545+callumforrester@users.noreply.github.com>

Co-authored-by: Garry O'Donnell <garry.o'donnell@diamond.ac.uk>
Co-authored-by: Callum Forrester <29771545+callumforrester@users.noreply.github.com>

tests/adapters/interpreters/command/test_command_interpreter.py

@@ -2,12 +2,16 @@
 from typing import Callable, Optional, Sequence
 
 import pytest
-from mock import AsyncMock, MagicMock
+from mock import AsyncMock, MagicMock, patch
 
 from tickit.adapters.interpreters.command import CommandInterpreter
 from tickit.adapters.interpreters.command.command_interpreter import Command
 from tickit.core.adapter import Adapter
 
+_GET_TYPE_HINTS = (
+    "tickit.adapters.interpreters.command.command_interpreter.get_type_hints"
+)
+
 
 @pytest.fixture
 def command_interpreter():
@@ -33,6 +37,10 @@ def parse(self, data: bytes) -> Optional[Sequence[str]]:
     return TestCommand
 
 
+@patch(
+    _GET_TYPE_HINTS,
+    lambda _: {"arg1": str, "arg2": str},
+)
 @pytest.mark.asyncio
 async def test_command_interpreter_handle_calls_func_with_args(
     command_interpreter: CommandInterpreter,
@@ -51,6 +59,10 @@ async def test_command_interpreter_handle_calls_func_with_args(
     test_adapter.test_method.assert_awaited_once_with("arg1", "arg2")
 
 
+@patch(
+    _GET_TYPE_HINTS,
+    lambda _: {"arg1": str, "arg2": str},
+)
 @pytest.mark.asyncio
 async def test_command_interpreter_handle_returns_iterable_reply(
     command_interpreter: CommandInterpreter,
@@ -70,6 +82,10 @@ async def test_command_interpreter_handle_returns_iterable_reply(
     assert reply == (await command_interpreter.handle(test_adapter, b"\x01"))[0]
 
 
+@patch(
+    _GET_TYPE_HINTS,
+    lambda _: {"arg1": str, "arg2": str},
+)
 @pytest.mark.asyncio
 async def test_command_interpreter_handle_wraps_non_iterable_reply(
     command_interpreter: CommandInterpreter,
@@ -94,6 +110,10 @@ async def test_command_interpreter_handle_wraps_non_iterable_reply(
     )
 
 
+@patch(
+    _GET_TYPE_HINTS,
+    lambda _: {"arg1": str, "arg2": str},
+)
 @pytest.mark.asyncio
 @pytest.mark.parametrize("interrupt", [True, False])
 async def test_command_interpreter_handle_returns_interupt(

tickit/adapters/interpreters/command/command_interpreter.py

@@ -1,6 +1,6 @@
 from abc import abstractmethod
 from inspect import getmembers
-from typing import AnyStr, AsyncIterable, Optional, Sequence, Tuple
+from typing import AnyStr, AsyncIterable, Optional, Sequence, Tuple, get_type_hints
 
 from tickit.core.adapter import Adapter, Interpreter
 from tickit.utils.compat.typing_compat import Protocol, runtime_checkable
@@ -90,6 +90,10 @@ async def handle(
             args = command.parse(message)
             if args is None:
                 continue
+            args = (
+                argtype(arg)
+                for arg, argtype in zip(args, get_type_hints(method).values())
+            )
             resp = await method(*args)
             if not isinstance(resp, AsyncIterable):
                 resp = CommandInterpreter._wrap(resp)