Skip to main content

Cucumber - my perspective

I have been using Cucumber (http://cukes.info/) at my current gig for about a year now. My initial reaction was that I absolutely hated it. It didn't seem to make sense for a programmer to write out tests (features) in plain English and then write out a bunch of regular expressions to turn that plain English into runnable code. What a palaver!

The other problem, is that the Cucumber tests were extremely fragile. Even making text and/or HTML changes would break things in lots of random places.

Anyways, as it turns out, I don't really hate Cucumber, I just hate the way it is implemented in my current gig. Here are some lessons I learnt on the way...

1) Features are not supposed to be written by programmers.
You can write features as a programmer, but you are not the intended audience. The reason why features are written in plain text is that they are supposed to be written by business owners. As a programmer though, you can use features to organize your thoughts in plain English.

For example

Given I am a shopper
When I add something to the cart
Then I should see it in the cart

2) Keep all implementation details out of the features.
The features are not for you (the programmer). They are for the business owners. You are just supposed to make them pass and use them as a guide.

3) Don't aim to re-use features
Testing is about the one place where DRY (Do not Repeat Yourself) does not apply. When you re-use the same tests/step definitions in multiple places, you are creating hidden dependencies between 2 sections of code which probably don't need to be there. A lot of developers also fall into this trap with CSS. As developers we are trained to look for similar behaviours and abstract them out into their own methods, but unless the business owner really decides the two features are linked, they should be kept separate. The one area where I don't agree with Cucumber is that all the step definitions are shared globally (I personally think each feature should have its own step definition file).

4) Features are not supposed to cover every possible edge case
Specs are used to make sure all your edge cases are covered. Features should only cover what is asked for by the business owners.

5) Do not tie your step definitions to HTML elements
This makes it impossible to do any redesign. It is a bit annoying that copy (or text) changes can break your tests, but at the end of the day, business owners are the ones who are in charge of copy and they should be aware that copy changes will come at a cost.

So at the end of the day, keep your features concise, don't reuse steps and write them like you are not a programmer and then you should be happy with Cucumber.

Comments

Popular posts from this blog

Freezing Gems

What is a gem and why would you want to freeze it?

In Ruby, there are times when you want to access pieces of functionality that other people of written (3rd party libraries) and you normally have 2 options. You can install a plug in or install a gem. Normally the method you use is determined by which ever is made available by the author.

Gems are installed on the host machine and are pretty handy when you want to run things in the command line or else across lots of projects, but their downside is that if you use a gem in a Rails project there is no automatic publishing mechanism when you deploy your site. You will need to log onto the remote host machine and install the gem manually.

Plugins are specific to Rails and are similar to gems in that they are also 3rd party libraries. However they are associated with your Rails project as opposed to your machine so they will get posted to the server on a regular deploy.

Freezing a gem is the process of transforming a gem into a plug in. Essen…

Unit/Functional Testing RubyAMF

One of my current projects is using RubyAMF to communicate with Flash (http://rubyforge.org/projects/rubyamf/). On the whole this is really nice because it allows you to transfer Ruby objects directly to ActionScript ones (as opposed to translating the object into XML, sending the XML and then recreating the object in ActionScript).
However, Rails does not provide a built in transport mechanism for AMF, so we cannot run functional testing directly on the data call (as we could for an XML or HTML transport layer). This is a show stopper for a lot of people (Rails w/o Unit testing = a big mess of trouble when something goes wrong).
We can though serve both the HTML and the AMF formats depending on the request format. This means that we can test the object instantiation logic and make sure there are no errors in the controllers (though we cannot check the actual format of the data being served). In the controller, instead of rendering AMF alone, do the following respond_to do |format|

Responsive Web Design

I wanted to go over Responsive Web Design using CSS.

In the old days of web development, we had to code to common screen sizes (i.e. 800 X 600, 1024 X 768) and we patiently waited for people to upgrade their computers to have a decent amount of screen real estate so we could design things the way we really wanted. We also took on semi stretchy web layouts etc to expand and contract appropriately.

Then about 2 or 3 years ago, Apple released this little device called an iPhone with a 320 X 480 resolution which took the world by storm and suddenly a lot of people were viewing your website on a tiny screen again...

Anyways, as it can be difficult to design a site which looks good on 320 X 480 AND 1680 X 1050, we need to come up with some kind of solution.

One way is to sniff the client and then use an appropriate stylesheet, but then you are mixing CSS with either JavaScript or server side programming and also potentially maintaining a list of appropriate clients and stylesheets. Also, you ca…