Improve test to include optional parameter

Author: oliwenmandiamond

tests/unit_tests/core/test_context.py

@@ -1,9 +1,10 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
+from inspect import Parameter
 from pathlib import Path
 from types import ModuleType, NoneType
-from typing import Any, Generic, TypeVar, Union
+from typing import Any, Generic, TypeVar, Union, get_args, get_type_hints
 from unittest.mock import ANY, MagicMock, Mock, patch
 
 import pytest
@@ -88,6 +89,10 @@ def has_some_params(foo: int = 42, bar: str = "bar") -> MsgGenerator:
     yield from ()
 
 
+def has_optional_parameter(foo: dict[str, Any] | None = None) -> MsgGenerator:
+    yield from ()
+
+
 def has_typeless_param(foo) -> MsgGenerator:
     yield from ()
 
@@ -169,7 +174,9 @@ def some_configurable() -> SomeConfigurable:
     return SomeConfigurable()
 
 
-@pytest.mark.parametrize("plan", [has_no_params, has_one_param, has_some_params])
+@pytest.mark.parametrize(
+    "plan", [has_no_params, has_one_param, has_some_params, has_optional_parameter]
+)
 def test_add_plan(empty_context: BlueskyContext, plan: PlanGenerator):
     empty_context.register_plan(plan)
     assert plan.__name__ in empty_context.plans
@@ -428,14 +435,25 @@ def test_with_config_passes_mock_to_with_dodal_module(
         mock_with_dodal_module.assert_called_once_with(ANY, mock=mock)
 
 
-def test_function_spec(empty_context: BlueskyContext):
+def test_function_spec_with_some_params(empty_context: BlueskyContext):
     spec = empty_context._type_spec_for_function(has_some_params)
     assert spec["foo"][0] is int
     assert spec["foo"][1].default == 42
     assert spec["bar"][0] is str
     assert spec["bar"][1].default == "bar"
 
 
+def test_function_spec_with_optional_params(empty_context: BlueskyContext):
+    spec = empty_context._type_spec_for_function(has_optional_parameter)
+    types = get_type_hints(has_optional_parameter)
+    arg_type = types.get("foo", Parameter.empty)
+
+    _type = SkipJsonSchema[empty_context._convert_type(arg_type, False)]
+    inner_type, *annotations = get_args(_type)
+    assert spec["foo"][0] == inner_type
+    assert spec["foo"][1].default is None
+
+
 def test_basic_type_conversion(empty_context: BlueskyContext):
     assert empty_context._convert_type(int) is int
     assert empty_context._convert_type(dict[str, int]) == dict[str, int]