Add tests for switch_working_directory helper

tests/test_helpers.py

@@ -2,8 +2,11 @@
 
 import os
 
+import pytest
+
 from tests.helpers import flatten_dict
 from tests.helpers import isolated_environment
+from tests.helpers import switch_working_directory
 
 
 def test_flatten_dict() -> None:
@@ -44,3 +47,25 @@ def test_isolated_environment_updates_environ() -> None:
     with isolated_environment(environ={"NEW_VAR": "new_value"}):
         assert os.environ["NEW_VAR"] == "new_value"
     assert "NEW_VAR" not in os.environ
+
+
+def test_switch_working_directory_restores_original_cwd_on_error(tmp_path) -> None:
+    original_cwd = os.getcwd()
+
+    with pytest.raises(RuntimeError):
+        with switch_working_directory(tmp_path):
+            assert os.getcwd() == str(tmp_path)
+            raise RuntimeError("boom")
+
+    assert os.getcwd() == original_cwd
+
+
+def test_switch_working_directory_remove_deletes_directory(tmp_path) -> None:
+    temp_dir = tmp_path / "temp-working-dir"
+    temp_dir.mkdir()
+
+    with switch_working_directory(temp_dir, remove=True):
+        assert os.getcwd() == str(temp_dir)
+        assert temp_dir.exists()
+
+    assert not temp_dir.exists()