def test_explain(self):
query = Query(['col1'])
expected = """
Data Source:
<none given> (assuming Selector object)
Execution Plan:
getattr, (<RESULT>, '_select'), {}
<RESULT>, (['col1']), {}
"""
expected = textwrap.dedent(expected).strip()
self.assertEqual(query._explain(file=None), expected)
def test_explain2(self):
query = Query(['label1'])
expected = """
Data Source:
<none given> (assuming Selector object)
Execution Plan:
getattr, (<RESULT>, '_select'), {}
<RESULT>, (['label1']), {}
"""
expected = textwrap.dedent(expected).strip()
# Defaults to stdout (redirected to StringIO for testing).
string_io = io.StringIO()
returned_value = query._explain(file=string_io)
self.assertIsNone(returned_value)
printed_value = string_io.getvalue().strip()
self.assertEqual(printed_value, expected)
# Get result as string.
returned_value = query._explain(file=None)
self.assertEqual(returned_value, expected)
