Make cucumber open the browser with the current page

The Cucumber Book describes a really nifty trick when testing web-pages: open the browser when a step fails. This is a feature provided by cucumber itself.

Add a support file features/support/debugging.rb:

After do |scenario|
  save_and_open_page if scenario.failed?
end

And add launchy to your gemfile, and bundle install. (or install it with whatever else you use).

group :test do
   #...
   gem "launchy", "~> 2.1.2"
end

This will save the page that cucumber is looking at, then open it in your browser. Works fine, untill you have a large suite of features and some refactoring breaks many features. Having to close twenty tabs in your browser after each run is counterproductive and often really frustrating.

I solved this with a flag that allows me to fire this debugging-trick only when I need it. When I have a failing scenario, and I want to investigate it by inspecting the page, I run my cucumber with an additional environment-variable:

$ cucumber debug=open
After do |scenario|
  save_and_open_page if scenario.failed? and (ENV["debug"] == "open")
end

The debug= syntax allows for more simple tricks too. Like debug=pp:

require "pp"
After do |scenario|
  save_and_open_page if scenario.failed? and (ENV["debug"] == "open")
  pp(page) if ENV["debug"] == "pp"
end

Simple trick, works like a charm.

Woodcut from Doré. Purely illustrative
Doré Woodcut. Its only function is to make the layout look better. And these images are really nice themselves

About the author: Bèr Kessels is an experienced webdeveloper with a great passion for technology and Open Source. A golden combination to implement that technology in a good and efficient way. Follow @berkes on Twitter. Or read more about Bèr.

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