Richard Lawrence » Ruby

Cucumber Tip: IRB From Inside a Step Definition

Richard Lawrence — Wed, 07 Dec 2011 20:05:35 +0000

Most Ruby programmers know about Ruby’s interactive console, IRB. (If you don’t, stop right here, open up a command window and run irb. Type some Ruby code. See how it returns the result of each line right away.) IRB is great for poking around with unfamiliar libraries.

Suppose you’re using Capybara with Cucumber for the first time. It would be nice to use IRB to experiment with what Capybara can do on a particular page. You could launch an IRB session and duplicate all the Capybara setup from your Cucumber support/env.rb file. But wouldn’t it be nice if you could just fire up IRB in the context of a step definition so you know everything in your IRB session matches what you’d get in the step def? Turns out you can. Here’s how…

Install the ruby-debug gem. If you’re using Ruby 1.9 like me, you need the ruby-debug19 gem. In Rails 3, just add gem ruby-debug19 to your Gemfile, probably in the test group, and run bundle install.

Require ruby-debug in support/env.rb.

Add breakpoint where you want to jump into IRB. For example:

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Given /^I am on the advanced search page$/ do
visit 'http://http://www.google.com/advanced_search'
breakpoint
0
end

(Note the extra line after breakpoint with 0 on it. breakpoint breaks before executing the next line, so if it’s the last thing in a block, you won’t jump into the debugger in the context you expect; 0 is a dummy line to keep us in the right context.)

Run Cucumber like normal. When it reaches breakpoint, ruby-debug will take over, and you’ll see a prompt like this: (rdb:1).

You can do a lot of different things at this prompt, but we only care about one right now: type irb and hit Enter. Now you should see a an IRB prompt. You’re in the context of a Cucumber step definition. Type self and hit Enter. You’ll see that self is an instance of Cucumber’s World with various things mixed in. From here, you can do anything you would do inside that step definition.

When you’re done, run quit to get out of IRB and continue to get out of the debugger. Cucumber execution will continue like normal. Keep in mind, though, that if you change the state of your system from IRB, you might not get the test results you expect.

Enhancements and variations for you to explore:

Make IRB nicer to use with gems such as irbtools
Create a step definition just for launching the debugger
Create a tagged scenario just for launching the debugger

Getting Started with Ruby, Cucumber, and Capybara on Windows

Richard Lawrence — Sat, 20 Aug 2011 15:23:20 +0000

The Ruby version of Cucumber isn’t just for Rails developers. If you have a .NET or Java web or service app, Ruby can be a great language for testing. With libraries like Capybara for driving web apps and JSON, RestClient, SOAP, and others for interacting with service apps, you’ll find testing in Ruby requires much less code than in C# or Java.

It can be hard to find instructions for setting up Ruby and Cucumber on Windows, though, so I’ve compiled these to help my clients get started, and I thought they might be useful to others. I’ve tested this on a clean Windows 7 VM, and everything works. Your mileage may vary, but let me know if you have any issues.

You’re going to be working in a command window quite a bit with Cucumber. You may want to customize your command window to make it more pleasant to use. I like the following settings (right click on the top left corner of the command window and choose Properties to set these):
Font: Consolas, 20pt
Screen Buffer: 120×3000
Window Size: 120×60

On a smaller screen, you’ll of course want a smaller window size and screen buffer. If you’re on an earlier version of Windows, you won’t be able to choose Consolas for the font, but Lucida Console is still better than the default.

I also like to set a PROMPT environment variable to $P$_$+$G (right click on My Computer and choose Properties, then Advanced, then Environment Variables).
Download and install Ruby. For Windows, http://rubyinstaller.org/ is the best option. Install the latest release of version 1.9.2. Make sure you check the option to “Add Ruby executables to your PATH.”
Also install the Ruby Development Kit from the same place, which will allow Ruby to build native extensions for libraries. Instructions are available here: https://github.com/oneclick/rubyinstaller/wiki/Development-Kit.
Confirm that the installation worked by opening a command window and running ruby -v. You should see a description of the Ruby version installed. If you see an error, something went wrong with the installation.
Make sure you have RubyGems installed by running gem -v on a command line. RubyGems is the package manager for Ruby and should come with the standard Ruby installation.
Run gem install cucumber to download and install Cucumber. Run cucumber --help to confirm that it worked.
Cucumber complains that you need ANSICON to get console colors because Windows doesn’t understand ANSI color escape sequences. Download ANSICON from http://adoxa.110mb.com/ansicon/index.html. Extract it somewhere (I put it in c:\utils\). In your command window, cd to either the x86 or x64 directory where you extracted ANSICON, depending on your OS, and run ansicon -i. Exit that command window and open a new one. Now, when you run cucumber --help, you should no longer see the message in the output about needing ANSICON.
Run gem install capybara to download and install the Capybara web automation library.
Run gem install rspec to download and install a nice library for readable assertions (among other things).
You’ll want Firefox with the Firebug plugin to do UI-related tests. If you haven’t already, install those.
You can edit Cucumber tests and automation code in Notepad, Visual Studio, or any other text editor. But I like having an editor that knows about Cucumber and provides Cucumber-oriented features, so I use JetBrains RubyMine to work with my Cucumber tests. There’s a free 30 day trial available.
To make sure Cucumber and Capybara are working nicely together, download and extract this Ruby, Cucumber, and Capybara Starter Project somewhere on your machine. Open a command window at the root of the folder (if you run dir or ls there, you should see a “features” folder). Run cucumber, and you should see all the tests run and pass.

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Another Look at WatiN

Richard Lawrence — Sat, 24 Jan 2009 16:29:50 +0000

At my current client, we’ve decided to use WatiN, largely for the C# vs. Ruby reason I discussed earlier this week. After spending a week working with WatiN (following a year of rarely using it), I’m impressed. Ruby and the active Watir community still have their advantages. But WatiN has really come into its own with C# 3.0 features like lambdas. I’m pleased with the test code we’re producing in terms of readability, speed, flexibility, and maintainability. I’ve proposed an Agile 2009 tutorial session on the patterns I’m using to get those results, and I’ll post more on that topic here soon. (Which will hopefully help with one of WatiN’s shortcomings—documentation.)

Web Testing for .NET Teams: WatiN or Watir?