fix test

src/seismometer/configuration/config_helpers.py

@@ -26,6 +26,8 @@ def generate_dictionary_from_parquet(
         for events section, by default "Type".
     """
     df = pd.read_parquet(inpath)
+    if df.empty:
+        raise ValueError("No data loaded; check the input file")
 
     datadict = None
     match section:
@@ -36,9 +38,6 @@ def generate_dictionary_from_parquet(
         case _:
             raise ValueError(f"Section {section} not recognized; only supports predictions and events")
 
-    if not datadict:
-        raise ValueError("No items generated; check the input file")
-
     write_yaml(datadict.model_dump(), outpath)
 
 
@@ -53,8 +52,12 @@ def _generate_prediction_dictionary(df: pd.DataFrame) -> PredictionDictionary:
 
 def _generate_event_dictionary(df, column="Type") -> EventDictionary:
     """Generates entry for each unique value in the specified column"""
-    items = [
-        DictionaryItem(name=c, dtype="string", definition=f"Placeholder description for {c}")
-        for c in df[column].unique()
-    ]
+    items = (
+        [
+            DictionaryItem(name=c, dtype="string", definition=f"Placeholder description for {c}")
+            for c in df[column].unique()
+        ]
+        if column in df
+        else []
+    )
     return EventDictionary(events=items)

tests/configuration/test_helpers.py

@@ -80,3 +80,11 @@ def test_generate_dict_invalid_section(self, mock_read):
             undertest.generate_dictionary_from_parquet("TESTIN", "out.yml", section=section_type)
 
         assert section_type in str(err.value)
+
+
+# This is intentionally outside the class to NOT use the shared pd patch
+@pytest.mark.parametrize("section_type", ["events", "predictions"])
+@patch.object(undertest.pd, "read_parquet", return_value=pd.DataFrame())
+def test_generate_dict_no_data_raises_error(mock_read, section_type, tmp_as_current):
+    with pytest.raises(ValueError, match="No data loaded"):
+        undertest.generate_dictionary_from_parquet("TESTIN", "out.yml", section=section_type)