lettuce 0.1 official release

Gabriel Falcão — Tue, 08 Jun 2010 04:40:41 +0000

27 days after its first release candidate, lettuce is now much mature and also got new features.

Lettuce is a BDD tool written in python, 100% based on cucumber.

There are two reasons for the name:

Lettuce is a green vegetable, just like cucumber the idea is that your tests must be always green.
Letuce is the name of a brazillian band that I pretty much like

Hands on!

There are links to lettuce’s official documentation at the end of this post, but there is a sneak peak:

Features are described in files with .feature extension and must be, by defaul within your project, in a folder called “features“.

Features are described like this:

In order to define steps all you need to do is write a new python file wihin features folder, Lettuce will import them all, recursively.

Example:

# -*- coding: utf-8 -*-
from lettuce import step, world, before
from some_module import NameJoiner

# setup
@before.each_scenario
def set_joined(scenario):
world.joined = []

# steps
@step('I have the following names')
def set_names(step):
world.people = step.hashes

@step('join them')
def join_names(step):
for person in world.people:
joiner = NameJoiner(
name=person["name"],
surname=person["surname"]
)
world.joined.append(joiner.join())

@step('I see the data')
def check_names(step):
for name, data in zip(world.joined, step.hashes):
assert name == data['joined']

(the full example is available here aqui)

Motivation

Since I started with TDD in Python I had many experiences, I’ve tested many mock mock libraries and test techniques.
In web projects I’ve used Pyccuracy, so that I could both describe behaviour of the application and make automated acceptance tests.

Althrough, I had a chance to try Cucumber with Django here at globo.com, and the result was: I fell in love with it, and had incredibly productive features, such as step tables which allows drawing a ascii table and map it into a list of hashes, and the scenario outlines.

From there I had THE inspiration: to implement a tool that works exactly like Cucumber, but in python.

Why ?

Python programmers it’s easier and frictionless to use libraries written in Python. I personally avoid mixing programming languages in a single project, some technologies can suit perfectly in the project, no matter in what language, but if there is a Python option, I will give it a go.

Cucumber IMHO one lib to make ruby even more “sexy”
Build a robust application, well tested required patience, what about turn it into fun ! ?
It’s easier to package python modules for debian/ubuntu.

Besides, even considering the fact that Cucumber already supports, would be more interesting to user pure python within step definitions.
Supposing that a web application will be written with Django and Cucumber, would be very useful to manipulate models within step definitions. However turning it possible, would need efforts to run rubypython, which the latest release dates october 2009.

Examples of similar libraries between python and ruby

Web framework:

ruby: rails
python: django

Micro web framework:

ruby: sinatra
python: cherrypy

Automated deploy:

ruby: capistrano
python: fabric

Behaviour-driven development:

ruby: cucumber
python: lettuce ?! (maybe ?! Who knows ?!  )

New projects + agile = releases

Gabriel Falcão — Sun, 05 Jul 2009 20:50:31 +0000

When I lived in Belo Horizonte/MG, I used to make hack parties with some friends of mine (nothing to say about all those pizzas and beer).

The hack parties had no specific goal, but a main idea: Hack some free software, and share the knowledge.

Many of us, but specifically Lincoln and I, used to create new projects in every hack party,but only a handful of those were actually released. It was often matter for jokes like: “Oh, you are up to raise the “too many projects” exception”.

I have two words for that fact: “not agile”.

Our projects were often POCs, and we had no culture of TDD, short releases and so on.

But since I started to work at Globo.com, I learned so much about agile, specially Scrum. And some months ago I’ve just accomplished what I call as “agile feeling”.

I mean, it’s a feeling that I can deliver software with quality in a short period of time.

But how ?

The idea is quite simple, you just have to follow some principles:

Think simple

This basically means focusing at the problem at hand, never trying to solve future problems you don’t have. Most of the time the problems your foresaw will never happen, yet you spent a lot of time preparing for them.

Test before programming

Write tests for small parts of your software, they will be very modular, and you will get a trust-able software, and I can assure you that you will be 100% able to embrace the changes.

Release fully functional versions, with simple features

As human beings, we want to embrace all possibilities and solve all possible problems at once.

But this is not agile at all. Talk to your client, be pragmatic, he will like to listen the truth: “You can not ship a full-featured final version of software within the term. But you can totally ship a primary version, fully functional, with all the basic needs of the client. Keep improving the software in next releases”

I tried to summarize those thoughts, but I need blog posts for each one.

Applying those thoughts to personal projects

As I said, I have unfinished projects, and they are still unfinished, mostly because were started with a non-agile approach, and I can’t get interested to finish them.

But there are a few projects I worked in, and others I am the creator. For instance:

Dead Parrot, a pythonic RESTFul framework django-based. Is on release 0.1-hellopolly, being used within some globo.com projects.
Ma-Chérie, a simple filesystem-based web application to navigate through pictures. Current release: 0.1
Sponge, a tiny web framework built on top of CherryPy and used Genshi as default template language. Sponge is the base of Ma-Chérie. Current release: 0.1
Pyccuracy, s BDD acceptance testing tool. Heynemann started that project, as a comitter, I worked in the biggest refactoring. Current release 1.0.3-viagra
Sleepy, is a crude, slow and rough template language, 100% based in regular expressions (which mades sleepy so slow). Actually I do not plan release it by now, I am just having some proofs of concept of how possible is to write a template language 100% regex based, just with TDD.

All projects above, except Sleepy, were released as well, all them were developed with TDD and have a good code coverage.

But the big deal is that, actually they will never get finished, for a simple reason. They will be in continuous development and continuous released as well.

By the way, if you want to contribute, just go to my github profile and check them out.

Agile Hacking » Free Software