lightning_talk.txt   [plain text]

Web Unittesting:

    How to do web unittesting without writing XML or .ini files
    
In charge of QA for an XP project with rapid development

Needed a test framework that would traverse a web application and ensure
correct behavior

This went through several iterations before acheiving some kind of sensible,
stable, trustworthy system.

A proud day when someone asked me how the tests were doing and I said,
"They're failing *correctly*"

Tests are comprised of stan-tag like objects in a list, which wrapped in an
interface and called in order.

     - tags for navigation, form posting, and assertions

This allows for highly-readable code, and since the application navigation is
changing constantly, this is important for making time-critical changes to the
tests.


so, how do we do it?

First, you must do a /tiny/ bit of embedding of attributes in your dom. For
most web-template based systems, I wouldn't imagine that this is all too
difficult. This test relies on having a unique 'id' attribute for each element
you wish to interact with. This is fairly trivial to implement inside nevow,
which is nice because all of the id attributes are auto-generated, and if an
element is added or removed, an id tag will be created for that new element.

The only problem I ran into was that our code is freakin complicated. 

Next, write a halfway decent python web client or get Moshe Zadka to write one
for you.

After you make a request, the client returns the dom, and twisted.web.microdom
parses the tree into a Page class.

One can then make assertions about the page using the familiar PyUnit syntax
(which basically amounts to string-comparisons)

When you want to follow another link, the Page class then pulls out the nodes
that have 'id' attributes into Link and Form classes when a request is made
for a particular object. I did this at request time so I wasn't creating a
whole bunch of objects that no one was going to use.

So, in the end, you wind up with a lightweight, pure-python way of performing
functional testing with an easily-readable test expression syntax.