Using this gem, whenever a Capybara test in Cucumber, Rspec or Minitest fails, the HTML for the failed page and a screenshot (when using capybara-webkit, Selenium or poltergeist) is saved into $APPLICATION_ROOT/tmp/capybara.
This is a huge help when trying to diagnose a problem in your failing steps as you can view the source code and potentially how the page looked at the time of the failure.
gem install capybara-screenshot
or update your Gemfile to include capybara-screenshot at the bottom (order respected as of Bundler 0.10):
gem 'capybara-screenshot', :group => :test
If you require more control, you can generate the screenshot on demand rather than on failure. This is useful if the failure occurs at a point where the screen shot is not as useful for debugging a rendering problem. This can be more useful if you disable the auto-generate on failure feature with the following config
Capybara::Screenshot.autosave_on_failure = false
Anywhere the Capybara DSL methods (visit, click etc.) are available so too will are the screenshot methods.
screen_shot_and_save_page
Or for screenshot only, which will automatically open the image.
screen_shot_and_open_image
These are just calls on the main library methods.
Capybara::Screenshot.screen_shot_and_save_page
Capybara::Screenshot.screen_shot_and_open_image
The gem supports the default rendering method for Capybara to generate the screenshot, which is:
page.driver.render(path)
There are also some specific driver configurations for Selenium, Webkit, and Poltergeist. See [https://github.com/mattheworiordan/capybara-screenshot/blob/master/lib/capybara-screenshot.rb](the definitions here). The Rack::Test driver, Rails' default, does not allow rendering, so it has a driver definition as a noop.
If a driver is not found the default rendering will be used. If this doesn't work with your driver, then you can add another driver configuration like so
# The driver name should match the Capybara driver config name.
Capybara::Screenshot.register_driver(:exotic_browser_driver) do |driver, path|
driver.super_dooper_render(path)
end
If you want to control the screenshot filename for a specific test libarary, to inject the test name into it for example, you can override how the basename is generated for the file like so
Capybara::Screenshot.register_filename_prefix_formatter(:rspec) do |example|
"screenshot-#{example.description.gsub(' ', '-')}"
end
end
A simple Rails 3.1 example application has been set up at https://github.com/mattheworiordan/capybara-screenshot-test-rails-3.1
Git clone the app, and then run Cucumber rake cucumber, RSpec rspec spec/**/*_spec.rb and Minitest rake test and expect intentional failures.
Now check the $APPLICATION_ROOT/tmp/capybara folder for the automatic screen shots generated from failed tests.
If you find that screen shots are not automatically being generated, then it's possible the capybara-screenshot gem is loading before your testing framework is loading, and thus unable to determine which framework to hook into. Make sure you include capybara-screenshot gem last in your Gemfile (order is respected by Bundler as of 0.10). Alternatively, manually require capybara-screenshot using one of the following based on your framework:
require 'capybara-screenshot/cucumber' # For Cucumber support
require 'capybara-screenshot/rspec' # For RSpec support
require 'capybara-screenshot/minitest' # For MiniSpec support
Raise an issue on the Capybara-Screenshot issue tracker if you are still having problems.
Please fork, submit patches or feedback at https://github.com/mattheworiordan/capybara-screenshot
The gem details on RubyGems.org can be found at https://rubygems.org/gems/capybara-screenshot
This gem was written by Matthew O'Riordan
Copyright © 2012 Matthew O'Riordan, inc. It is free software, and may be redistributed under the terms specified in the LICENSE file.