Old xml.etree.cElementTree versions (python2) reorder the attributes
while recent xml.etree.cElementTree versions (python3) keep the
document order.
Example:
python3:
>>> ET.tostring(ET.fromstring('<foo y="foo" x="bar"/>'))
b'<foo y="foo" x="bar" />'
>>>
python2:
>>> ET.tostring(ET.fromstring('<foo y="foo" x="bar"/>'))
'<foo x="bar" y="foo" />'
>>>
So far, the testsuite compared two serialized XML documents via a simple
string comparison. For instance via,
self.assertEqual(actual_serialized_xml, expected_serialized_xml) where
the expected_serialized_xml is, for instance, a hardcoded str. Obviously,
this would only work for python2 or python3.
In order to support both python versions, we first parse both XML
documents and then compare the corresponding trees (this is OK because
we do not care about comments etc.).
A related issue is the way how the testsuite compares data that is "send"
to the API. So far, this was a plain bytes comparison. Again, this won't
work in case of XML documents (see above). Moreover, we have currently
no notion to "indicate" that the transmitted data is an XML document.
As a workaround, we keep the plain bytes comparison and in case it fails,
we try an xml comparison (see above) as a last resort. Strictly speaking,
this is "wrong" (there might be cases (in the future) where we want to
ensure that the transmitted XML data is bit identical to a fixture file)
but a reasonable comprise for now.
Fixes: #751 ("[python3.8] Testsuite fails")
Importing `cElementTree` has been deprecated since Python 3.3 -
importing `ElementTree` automatically uses the fastest
implementation available - and is finally removed in Python 3.9.
Importing cElementTree directly (not as part of xml) is an even
older relic, it's for Ye Time Before ElementTree Was Added To
Python and it was instead an external module...which was before
Python 2.5.
We still need to work with Python 2.7 for now, so we use a try/
except to handle both 2.7 and 3.9 cases. Also, let's not repeat
this import 12 times in one file for some reason.
Signed-off-by: Adam Williamson <awilliam@redhat.com>
There is no need to compute the request creator, because it is
stored in the request xml. Moreover, the old computation yields
a wrong result (see issue #286).
