Function test_export_import_exception_reader

python/pyarrow/tests/test_cffi.py:474–504

()

@needs_cffi
def test_export_import_exception_reader():
    # See: https://github.com/apache/arrow/issues/37164
    c_stream = ffi.new("struct ArrowArrayStream*")
    ptr_stream = int(ffi.cast("uintptr_t", c_stream))

    gc.collect()  # Make sure no Arrow data dangles in a ref cycle
    old_allocated = pa.total_allocated_bytes()

    def gen():
        if True:
            try:
                raise ValueError('foo')
            except ValueError as e:
                raise NotImplementedError('bar') from e
        else:
            yield from make_batches()

    original = pa.RecordBatchReader.from_batches(make_schema(), gen())
    original._export_to_c(ptr_stream)

    reader = pa.RecordBatchReader._import_from_c(ptr_stream)
    with pytest.raises(NotImplementedError) as exc_info:
        reader.read_next_batch()

    # inner *and* outer exception should be present
    assert 'ValueError: foo' in str(exc_info.value)
    assert 'NotImplementedError: bar' in str(exc_info.value)
    # Stacktrace containing line of the raise statement
    assert 'raise ValueError(\'foo\')' in str(exc_info.value)

    assert pa.total_allocated_bytes() == old_allocated


@needs_cffi