Skip to main content

Flow Testing - Initial Ideas

I'm toying with the idea of a new way to write tests. This is a cross between state and interaction based testing, and also tries to make setting up the test environments easier. I call it "Flow Testing" as it tests how the various states of the test target flow from one to the next.

The idea is several-fold. We begin on the idea that we are testing names, because everything in Python starts with a name. You will test different things about names, such as type, what attributes or other properties apply to certain conditions, etc.

Flow testing is very tree-oriented. For every name, you define the state you expect to begin, and branch into the state you expect for various properties. For example, you may have a state for the name 'foo' and a branch state for 'foo.bar'. These are branches within one state, while wthere are other branches across states called Interaction Branches. These states define the interactions that lead to them and the states expected.

The example below defines a test for a simple module that should have a simple function. It defines that the name foo should be a module and that the state of its 'bar' attribute should be a callable. It then defines the state of a call to bar, and details it under more specific conditions of the interaction (specific arguments given).

import flowtest

import foo


class test_foo(flowtest.State):
targetType = flowtest.module
targetHasAttributes = ('bar',)

class test_bar(flowtest.State):
targetType = flowtest.callable

class testReturn(flowtest.State):
targetType = basestring

class testReturn(flowtest.State):
flowtest.callArguments()
flowtest.callArguments('hi')

targetContains = u"hello"

class testReturn(flowtest.State):
flowtest.callArguments('bye')

targetType = basestring
targetContains = u"goodbye"


This is just an idea, and does not work or exist yet. Any comments? If it seems solid, I'd like to start working on it.

Comments

fumanchu said…
Hmm. My first reaction to the example code is, "what does it do?" Lots of inner classes (that never get instantiated?!) is off-putting at best. Isn't there a way to implement it so the user writes normal, imperative OO Python?

Also, the string "flowstate." is in there way too many times IMO to be an easy-to-use API. :/ Wouldn't it be cleaner if most of those were replaced with "self." (since you're already subclassing flowstate.State, etc.)?

Popular posts from this blog

CARDIAC: The Cardboard Computer

I am just so excited about this. CARDIAC. The Cardboard Computer. How cool is that? This piece of history is amazing and better than that: it is extremely accessible. This fantastic design was built in 1969 by David Hagelbarger at Bell Labs to explain what computers were to those who would otherwise have no exposure to them. Miraculously, the CARDIAC (CARDboard Interactive Aid to Computation) was able to actually function as a slow and rudimentary computer.  One of the most fascinating aspects of this gem is that at the time of its publication the scope it was able to demonstrate was actually useful in explaining what a computer was. Could you imagine trying to explain computers today with anything close to the CARDIAC? It had 100 memory locations and only ten instructions. The memory held signed 3-digit numbers (-999 through 999) and instructions could be encoded such that the first digit was the instruction and the second two digits were the address of memory to operate on

The Range of Content on Planet Python

I've gotten a number of requests lately to contribute only Python related material to the Planet Python feeds and to be honest these requests have both surprised and insulted me, but they've continued. I am pretty sure they've come from a very small number of people, but they have become consistent. This is probably because of my current habit of writing about NaNoWriMo every day and those who aren't interested not looking forward to having the rest of the month reading about my novel. Planet Python will be getting a feed of only relevant posts in the future, but I'm going to be honest: I am kind of upset about it. I don't care if anyone thinks it is unreasonable of me to be upset about it, because the truth is Planet Python means something to me. It was probably the first thing I did that I considered "being part of the community" when I submitted my meager RSS feed to be added some seven years ago. My blog and my name on the list of authors at Plan

Interrupting Coders Isn’t So Bad

Here’s a hot take: disrupting coders isn’t all that bad. Some disruptions are certainly bad but they usually aren’t. The coder community has overblown the impact. A disruption can be a good thing. How harmful disruption might be a symptom of other problems. There are different kinds of disruptions. They are caused by other coders on your team, managers and other non-coders, or meetings throughout the day. The easiest example to debunk is a question from a fellow developer. Imagine someone walks over to your desk or they ping you on Slack, because they have “one quick question.” Do you get annoyed at the interruption when you were in the middle of something important? You help out your teammate quickly and get back to work, trying to pick up where you left off. That’s a kind of interruption we complain about frequently, but I’m not convinced this is all that bad. You are being disrupted but your team, of which you are only one member of the whole unit, is working smoothly. You u