Wraith

• Website: http://responsivenews.co.uk
• Source: http://github.com/bbc-news/wraith

Wraith is a screenshot comparison tool, created by developers at BBC News.

What is it?

Wraith uses either PhantomJS or SlimerJS to create screenshots of different environments and then creates a diff of the two images, the affected areas are highlighted in blue

Requirements

You'll need either PhantomJS or SlimerJS, ImageMagick & Ruby 1.9.3 or greater. It's up to you to decide which browser engine you want to run it against.

On Mac OS X, the install script will install PhantomJS & ImageMagick for you, assuming you have homebrew installed, otherwise it'll tell you to install them.

Also install the image_size gem:

gem install image_size

Then, to ensure gem dependencies are installed:

bundle

On Ubuntu 12.04, you will need to apt-get the following packages:

• libicu-dev
• imagemagick
• rake

And then download the PhantomJS binary package from http://phantomjs.org/.

Installation

curl -fsSL https://raw.github.com/bbc-news/wraith/go/install | bash
cd wraith
bundle install

Config

All config will be placed in config.yaml. You can specify the snap file name, this could be used in a situation where you have a large amount of config files. You can set domains of the 2 sites you are comparing, URL paths, screen widths & HTTP headers.

#If you want to have multiple snapping files, set the file name here
snap_file: "snap.js"

# Type the name of the directory that shots will be stored in
directory:
  - 'shots'

# Add only 2 domains, key will act as a label
domains:
  english: "http://www.live.bbc.co.uk/news"
  russian: "http://www.live.bbc.co.uk/russian"

#Type screen widths below, here are a couple of examples
screen_widths:
  - 320
  - 600
  - 768
  - 1024
  - 1280

#Type page URL paths below, here are a couple of examples
paths:
  home: /
  uk_index: /uk

You can also specify PhantomJS command line options in config.yaml.

For example to tell PhantomJS to ignore SSL errors:

phantomjs_options: "--ignore-ssl-errors=true"

Using Wraith

There are two ways of using Wraith, the fastest is to simply type rake.

rake

You may want to deal with multiple config files though, different pages, different sites or different viewports. In order to handle this, you can pass in a different config file by typing the following into terminal. The default is config.yaml, so even if you dont pass a file in, it will still run.

rake config[config_name]

Output

After each screenshot is captured, the compare task will run, this will output a diff.png and a data.txt. The data.txt for each file will show the number of pixels that have changed. There is a main data.txt which is in the root of the output folder that will combine all of these values to easier view all the pixel changes.

Gallery

A gallery is available to view each of the images and the respective diff images located in the shots folder once all the images have been compared.

Contributing

If you want to add functionality to this project, pull requests are welcome.

• Create a branch based off master and do all of your changes with in it.
• If you have to pause to add a 'and' anywhere in the title, it should be two pull requests.
• Make commits of logical units and describe them properly
• Check for unnecessary whitespace with git diff --check before committing.
• If possible, submit tests to your patch / new feature so it can be tested easily.
• Assure nothing is broken by running all the test
• Please ensure that it complies with coding standards.

Please raise any issues with this project as a GitHub issue.

Running Tests

rspec

## Changelog - updated 22/9/13 Merge pull request #46 from BBC-News/different_snap_file Merge pull request #41 from BBC-News/new-config Merge pull request #40 from tiemevanveen/master Merge pull request #36 from thingsinjars/patch-1 Merge pull request #37 from thingsinjars/patch-2 Merge pull request #34 from malengrin/master Merge pull request #33 from hoguej/feature/point_directly_at_install_script Merge pull request #22 from doryphores/phantomjs_options Merge pull request #27 from reggieb/code_tidy Merge pull request #24 from hoguej/feature/unit_tests Merge pull request #21 from doryphores/sort_files_before_compare Merge pull request #13 from BBC-News/crop-images Merge pull request #18 from ecometrica/gallery Merge pull request #15 from timabell/move-data-file Merge pull request #14 from timabell/unnamed-paths Merge pull request #5 from BBC-News/typekit-fix Merge pull request #8 from jaredly/patch-1 Merge pull request #2 from Kami/fix_ruby_compatibility Merge pull request #1 from BBC-News/freedom

License

Wraith is available to everyone under the terms of the Apache 2.0 open source licence. Take a look at the LICENSE file in the code.

Credits

• Dave Blooman
• John Cleveley
• Simon Thulbourn