feat: reset

src/scverse_misc/_settings.py

@@ -126,6 +126,31 @@ def override(self, **kwargs: object) -> Generator[None]:
             for argname, argval in reversed(oldsettings.items()):
                 setattr(self, argname, argval)
 
+    def reset(self, *args: str) -> AbstractContextManager[frozenset[str]]:
+        """Reset passed settings to their default values.
+
+        Can be used as a context manager to make the resets temporary.
+        On `__enter__`, the context manager returns the settings that have been changed.
+        """
+        prev_values = {arg: getattr(self, arg) for arg in args if arg in self.model_fields_set}
+
+        # since we want to allow using this method imperatively,
+        # eagerly do the reset here instead of returning a context manager with a lazy `__enter__`.
+        for arg in prev_values:
+            default = type(self).model_fields[arg].get_default()
+            setattr(self, arg, default)
+            self.model_fields_set.remove(arg)
+
+        class Cm(AbstractContextManager[frozenset[str]]):
+            def __enter__(_self) -> frozenset[str]:
+                return frozenset(prev_values)
+
+            def __exit__(_self, *_: object) -> None:
+                for arg, value in prev_values.items():
+                    setattr(self, arg, value)
+
+        return Cm()
+
     @classmethod
     def __pydantic_init_subclass__(  # type: ignore[override]
         subcls: type[Self], *, exported_object_name: str, docstring_style: Literal["google", "numpy", "scverse"]

tests/test_settings.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import inspect
+from contextlib import nullcontext
 from pathlib import Path
 from typing import TYPE_CHECKING, Annotated, Literal, cast
 
@@ -87,13 +88,25 @@ def test_override(settings: DummySettings) -> None:
         assert settings.field_bool is True
     assert settings.field_bool is False
 
+
+def test_override_error(settings: DummySettings) -> None:
     with pytest.raises(ValidationError):
         with settings.override(field_int_range=3, field_no_docstring=1.1):
             pass
     assert settings.field_no_docstring == 42
     assert settings.field_int_range == 1
 
 
+@pytest.mark.parametrize("temp", [True, False], ids=["temporary", "permanent"])
+def test_reset(settings: DummySettings, temp: bool) -> None:
+    default = settings.field_bool
+    settings.field_bool = not default
+    undo_reset = settings.reset("field_bool")
+    with undo_reset if temp else nullcontext():
+        assert settings.field_bool is default
+    assert settings.field_bool is (not default if temp else default)
+
+
 @pytest.mark.parametrize("docstring_style", ["google", "numpy", "scverse"], indirect=True)
 def test_docs(docstring_style: Literal["google", "numpy"], settings: DummySettings) -> None:
     parser = GoogleDocstring if docstring_style == "google" else NumpyDocstring