Improve test coverage

tests/io/test_hdf.py

@@ -1,6 +1,6 @@
 from pathlib import Path
 
-from pytest import raises
+from pytest import raises, mark
 import numpy as np
 import pandas as pd
 import tables
@@ -28,23 +28,31 @@ def test_store_df(tmpdir):
         assert np.allclose(df_copy['b'], [1., 3.])
 
 
-def test_append(tmpdir):
+@mark.parametrize('prefix', [None, 'a'])
+def test_append(tmpdir, prefix):
     writer = HDF5Writer()
     out_file = Path(tmpdir) / 'example.h5'
 
     # Write the initial data
     with tables.open_file(out_file, mode='w') as file:
-        writer.add_table(file, 'example_table', example_df, ColumnSchema())
+        if prefix is not None:
+            file.create_group(file.root, prefix)
+
+        writer.add_table(file, 'example_table', example_df, ColumnSchema(), prefix)
 
     # Append the data again
     with tables.open_file(out_file, mode='a') as file:
-        writer.append_to_table(file, 'example_table', example_df)
+        writer.append_to_table(file, 'example_table', example_df, prefix)
 
-        table = file.get_node('/example_table')
+        table = file.get_node('/example_table' if prefix is None else f'/{prefix}/example_table')
         df_copy = read_df_from_table(table)
         assert len(df_copy) == len(example_df) * 2
         assert np.allclose(df_copy['a'], [1, 2, 1, 2])
 
         # Test data check
         with raises(ValueError, match='Existing and new'):
-            writer.append_to_table(file, 'example_table', pd.DataFrame({'a': [1., 2.]}))
+            writer.append_to_table(file, 'example_table', pd.DataFrame({'a': [1., 2.]}), prefix)
+
+        # Test bad prefix
+        with raises(ValueError, match='No data available for prefix'):
+            writer.append_to_table(file, 'example_table', pd.DataFrame({'a': [1., 2.]}), prefix='b')