Include stack trace when sampling errors are surfaced (#2329)

sdv/single_table/utils.py

@@ -103,7 +103,7 @@ def handle_sampling_error(output_file_path, sampling_error):
         )
 
     if error_msg:
-        raise type(sampling_error)(error_msg + '\n' + str(sampling_error))
+        raise type(sampling_error)(error_msg) from sampling_error
 
     raise sampling_error
 

tests/unit/single_table/test_base.py

@@ -1546,15 +1546,17 @@ def test__sample_with_progress_bar_without_output_filepath(self):
         instance._fitted = True
         expected_message = re.escape(
             'Error: Sampling terminated. No results were saved due to unspecified '
-            '"output_file_path".\nMocked Error'
+            '"output_file_path".'
         )
         instance._sample_in_batches.side_effect = RuntimeError('Mocked Error')
 
         # Run and Assert
-        with pytest.raises(RuntimeError, match=expected_message):
+        with pytest.raises(RuntimeError, match=expected_message) as exception:
             BaseSingleTableSynthesizer._sample_with_progress_bar(
                 instance, output_file_path=None, num_rows=10
             )
+        assert isinstance(exception.value.__cause__, RuntimeError)
+        assert 'Mocked Error' in str(exception.value.__cause__)
 
     @patch('sdv.single_table.base.datetime')
     def test_sample(self, mock_datetime, caplog):

tests/unit/single_table/test_utils.py

@@ -215,10 +215,13 @@ def test_unflatten_dict():
 def test_handle_sampling_error_temp_file():
     """Test that an error is raised when temp dir is ``False``."""
     # Run and Assert
-    error_msg = 'Error: Sampling terminated. Partial results are stored in test.csv.\nTest error'
-    with pytest.raises(ValueError, match=error_msg):
+    error_msg = 'Error: Sampling terminated. Partial results are stored in test.csv.'
+    with pytest.raises(ValueError, match=error_msg) as exception:
         handle_sampling_error('test.csv', ValueError('Test error'))
 
+    assert isinstance(exception.value.__cause__, ValueError)
+    assert 'Test error' in str(exception.value.__cause__)
+
 
 def test_handle_sampling_error_false_temp_file_none_output_file():
     """Test the ``handle_sampling_error`` function.
@@ -228,9 +231,12 @@ def test_handle_sampling_error_false_temp_file_none_output_file():
     """
     # Run and Assert
     error_msg = 'Test error'
-    with pytest.raises(ValueError, match=error_msg):
+    with pytest.raises(ValueError) as exception:
         handle_sampling_error('test.csv', ValueError('Test error'))
 
+    assert isinstance(exception.value.__cause__, ValueError)
+    assert error_msg in str(exception.value.__cause__)
+
 
 def test_handle_sampling_error_ignore():
     """Test that the error is raised if the error is the no rows error."""