Beautiful Testing

Conclusions

In our quest to create beautiful tests for checking XMPP protocol implementations, we started out by testing simple request-response protocols at the lowest level: the data sent over the network stream. After discovering that this form of testing does not really scale well, we abstracted out the protocol to a higher level, up to the point where the tests used only high-level data structures. By testing protocol behavior on a high level, we were able to write tests for more complex protocols without compromising the clarity of the tests. For the most complex protocols, writing scenarios helped to cover all of the possible situations that can arise in a protocol session. Finally, since XMPP is an open protocol with many different implementations, it’s very important to test an XMPP application on the real network, to ensure interoperability with other implementations. By running small test programs regularly, we were able to test the system in its entirety, and check whether our implementation of the protocol plays together nicely with other entities on the network.

The focus of this chapter has mostly been on testing the protocol functionality in XMPP implementations, as this is probably the most important part of quality control in XMPP. However, many other forms of testing exist in the XMPP world besides protocol tests. For example, performance testing is very crucial in the world of XMPP servers. Simple test scripts or programs like the ones described earlier can ...