Introducing unittest-xml: testing XML in Python

Note, this article was published over 5 years ago and hence the content may be stale. Consume with a pinch of salt.

For some reason, I keep finding myself writing unit tests that need to make assertions about an XML document. To keep things DRY, I've packaged up my custom assertion methods as a PyPi module: unittest-xml. There's a small chance it may be useful to others.

Sample Usage

Enable the additional assert methods using a mixin:

import unittest
from xmltest import XMLAssertions


class SampleTestCase(unittest.TestCase, XMLAssertions):
    ...

Now suppose that the expected XML from some SUT [1] is:

<?xml version="1.0" encoding="UTF-8" ?>
<Response>
    <CardTxn>
        <authcode>060642</authcode>
        <card_scheme>Switch</card_scheme>
        <issuer country="UK">HSBC</issuer>
    </CardTxn>
    <reference>3000000088888888</reference>
    <merchantreference>1000001</merchantreference>
    <mode>LIVE</mode>
    <reason>ACCEPTED</reason>
    <status>1</status>
    <time>1071567305</time>
</Response>

then you can make assertions about the document using 3 additional assertions methods.

self.assertXPathNodeCount(RESPONSE, 1, 'CardTxn/authcode')
self.assertXPathNodeText(RESPONSE, 'LIVE', 'mode')
self.assertXPathNodeAttributes(RESPONSE, {'country': 'UK'}, 'CardTxn/issuer')

The first argument to each method is the XML string, the second is the expected value, while the third is the XPath query.

Installation

The standard way:

pip install unittest-xml

Discussion

Note, the implementation uses ElementTree and so only a subset of the XPath specification is implemented. However the above three assertion methods are sufficient for most scenarios.

The code is on Github, as usual.

[1]System under test