Fix CLI fixture persisting structlog configuration (#53)

* Add fixture to reset structlog configuration after using the CLI fixture

* Remove xfail that is no longer necessary

tests/cli/conftest.py

@@ -1,15 +1,31 @@
-from collections.abc import Callable
+from collections.abc import Callable, Iterator
 
 import pytest
+import structlog
 from anycastd._cli.main import app
 from click.testing import Result
 from typer.testing import CliRunner
 
 
 @pytest.fixture
-def anycastd_cli() -> Callable[..., Result]:
+def reset_structlog_config() -> Iterator[None]:
+    """Reset structlog configuration after running a test.
+
+    This is required for tests that invoke the anycastd CLI, as running it
+    initializes the structlog configuration, adding filters that could affect
+    other tests.
+    """
+    yield
+    structlog.reset_defaults()
+
+
+@pytest.fixture
+def anycastd_cli(reset_structlog_config) -> Callable[..., Result]:
     """A callable that runs anycastd CLI commands.
 
+    To make sure that this fixture does not affect other tests, state that is
+    initialized when running the CLI needs to be reset after using this fixture.
+
     Example:
     ```python
     >>> result = anycastd_cli("run", "--help")

tests/cli/test_main.py

@@ -101,9 +101,6 @@ def test_log_format_configures_structlog(self, anycastd_cli, arg: str, processor
         assert isinstance(last_processor, processor)
 
 
-@pytest.mark.xfail(
-    reason="Above tests configure a persistent log level filter.", strict=False
-)
 def test_reading_configuration_is_logged(mocker):
     """Reading the configuration is logged."""
     path = Path("/path/to/config.toml")