motion-screenspecs

Test your RubyMotion app regressions using screenshot comparison (similar to Huxley and Wraith):

$ rake spec

AppScreenshots
  - should take screenshots

AppScreenshots.menu
  - should be <= 5.0% difference

AppScreenshots.timeline
  - should be <= 5.0% difference [FAILED - was 10.75%]

Bacon::Error: was 10.75%
    spec.rb:698:in `satisfy:': AppScreenshots.timeline - should be <= 5.0% difference
    spec.rb:438:in `execute_block'
    spec.rb:402:in `run_postponed_block:'
    spec.rb:397:in `resume'

3 specifications (3 requirements), 1 failures, 0 errors

(calculated diffs are truer than visual representation)

Add this line to your application's Gemfile:

gem 'motion-screenspecs'

And then execute:

$ bundle

Or install it yourself as:

$ gem install motion-screenspecs

motion-screenspecs works in unison with motion-screenshots. Here are the steps you need to get everything working:

1. Create a subclass of Motion::Screenshots::Base (see the motion-screenshots README).

2. Create the following directory structure:

   spec/
     screenshots/
       [YourScreenshotSubclass]
         expectations/
           [title of your screenshot].png
           [title of your other screenshot].png
           [etc].png
   

   The images in expectations are known values for your app. You can take these screenshots manually or using motion-screenshots' rake screenshots.

   Failing image diffs will be saved in spec/screenshots/[YourScreenshotSubclass]/failures. All results from the latest test are saved to spec/screenshots/[YourScreenshotSubclass]/results.

3. Add a call to tests_screenshots in your specs:

   describe "Screenshots" do
     tests_screenshots AppScreenshots
   end

The sample app is a complete example with a failing test.

Hats off to Jeff Kreeftmeijer for the image diffing help!

There's a couple of configuration options you can use:

Motion::Project::App.setup do |app|
  # Set your tolerance % for image differences
  Motion::Screenspecs.set_tolerance(5.0, app)

  # Set how long the tests will wait for your screenshots to finish
  Motion::Screenspecs.set_screenshot_timeout(120, app)

  # Set how long the tests will wait for a given image to finish diffing
  Motion::Screenspecs.set_diff_timeout(20, app)

  # Set whether or not your failed diffs will open in Finder upon finishing tests
  Motion::Screenspecs.open_failures_at_exit = true
end

rake spec

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Clay Allsopp @clayallsopp