Address PR comments

docs/notebooks/test_snia.ipynb

@@ -47,7 +47,7 @@
    "source": [
     "from tdastro.astro_utils.opsim import OpSim, oversample_opsim\n",
     "\n",
-    "opsim_name = Path(tdastro._TDASTRO_TEST_DATA_DIR, \"opsim_shorten.db\")\n",
+    "opsim_name = tdastro._TDASTRO_TEST_DATA_DIR / \"opsim_shorten.db\"\n",
     "base_opsim = OpSim.from_db(opsim_name)\n",
     "oversampled_observations = oversample_opsim(\n",
     "    base_opsim,\n",

tests/tdastro/test_graph_state.py

@@ -1,6 +1,3 @@
-import tempfile
-from pathlib import Path
-
 import numpy as np
 import pytest
 from astropy.table import Table
@@ -378,27 +375,26 @@ def test_graph_state_update_multi():
         state.update(state4)
 
 
-def test_graph_to_from_file():
+def test_graph_to_from_file(tmp_path):
     """Test that we can create an AstroPy Table from a GraphState."""
     state = GraphState(num_samples=3)
     state.set("a", "v1", [1.0, 2.0, 3.0])
     state.set("a", "v2", [3.0, 4.0, 5.0])
     state.set("b", "v1", [6.0, 7.0, 8.0])
 
-    with tempfile.TemporaryDirectory() as dir_name:
-        file_path = Path(dir_name, "state.ecsv")
-        assert not file_path.is_file()
+    file_path = tmp_path / "state.ecsv"
+    assert not file_path.is_file()
 
-        state.save_to_file(file_path)
-        assert file_path.is_file()
+    state.save_to_file(file_path)
+    assert file_path.is_file()
 
-        state2 = GraphState.from_file(file_path)
-        assert state == state2
+    state2 = GraphState.from_file(file_path)
+    assert state == state2
 
-        # Cannot overwrite with it set to False, but works when set to True.
-        with pytest.raises(OSError):
-            state.save_to_file(file_path)
-        state.save_to_file(file_path, overwrite=True)
+    # Cannot overwrite with it set to False, but works when set to True.
+    with pytest.raises(OSError):
+        state.save_to_file(file_path)
+    state.save_to_file(file_path, overwrite=True)
 
 
 def test_transpose_dict_of_list():