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 operat...

Statement Functions

At a small suggestion in #python, I wrote up a simple module that allows the use of many python statements in places requiring statements. This post serves as the announcement and documentation. You can find the release here . The pattern is the statement's keyword appended with a single underscore, so the first, of course, is print_. The example writes 'some+text' to an IOString for a URL query string. This mostly follows what it seems the print function will be in py3k. print_("some", "text", outfile=query_iostring, sep="+", end="") An obvious second choice was to wrap if statements. They take a condition value, and expect a truth value or callback an an optional else value or callback. Values and callbacks are named if_true, cb_true, if_false, and cb_false. if_(raw_input("Continue?")=="Y", cb_true=play_game, cb_false=quit) Of course, often your else might be an error case, so raising an exception could be useful...

How To Teach Software Development

How To Teach Software Development Introduction Developers Quality Control Motivation Execution Businesses Students Schools Education is broken. Education about software development is even more broken. It is a sad observation of the industry from my eyes. I come to see good developers from what should be great educations as survivors, more than anything. Do they get a headstart from their education or do they overcome it? This is the first part in a series on software education. I want to open a discussion here. Please comment if you have thoughts. Blog about it, yourself. Write about how you disagree with me. Write more if you don't. We have a troubled industry. We care enough to do something about it. We hark on the bad developers the way people used to point at freak shows, but we only hurt ourselves but not improving the situation. We have to deal with their bad code. We are the twenty percent and we can't talk to the eighty percent, by definition, so we need to impro...