scribble-math/dockers/Screenshotter
Martin von Gagern 2e002ff37a Use jspngopt and pako to create reproducible PNG files for Chrome as well
The combination of jspngopt and pako should eliminate possible causes for
different PNG encodings, although the core reason for #325 remains unknown.
Pako has poorer compression rates than native libz, but optimization can
counter that effect, and actually reduce the size of the screenshots.

The screenshots for LimitControls and UnsupportedCmds on Firefox used to
exhibit subpixel rendering before, for reasons unknown.  The regenerated
versions don't exhibit this.  See #324 for a discussion.
2015-08-30 02:12:55 +02:00
..
README.md Automatically start a development server 2015-07-15 15:41:29 +02:00
screenshotter.js Use jspngopt and pako to create reproducible PNG files for Chrome as well 2015-08-30 02:12:55 +02:00
screenshotter.sh Use jspngopt and pako to create reproducible PNG files for Chrome as well 2015-08-30 02:12:55 +02:00

How to generate screenshotter images

Automatic generation of screen shots

Now you too can generate screenshots from your own computer, and (hopefully) have them look mostly the same as the current ones! Make sure you have docker installed and running. If all you want is (re)create all the snapshots for all the browsers, then you can do so by running the screenshotter.sh script:

dockers/Screenshotter/screenshotter.sh

It will fetch all required selenium docker images, and use them to take screenshots.

Manual generation

If you are creating screenshots on a regular basis, you can keep the docker containers with the selenium setups running. Essentially you are encouraged to reproduce the steps from screenshotter.sh manually. Example run for Firefox:

container=$(docker run -d -P selenium/standalone-firefox:2.46.0)
node dockers/Screenshotter/screenshotter.js -b firefox -c ${container}
# possibly repeat the above command as often as you need, then eventually
docker stop ${container}
docker rm ${container}

For Chrome, simply replace both occurrences of firefox with chrome.

Use without docker

It is possible to run screenshotter.js without the use of Docker:

npm install selenium-webdriver
node dockers/Screenshotter/screenshotter.js

This will generate screenshots using the Firefox installed on your system. Browsers other than Firefox can be targeted using the --browser option. For a complete list of options pass --help as an argument to screenshotter.js. Using these it should be possible to have the script connect to almost any Selenium web driver you might have access to.

Note that screenshots taken without Docker are very likely to disagree from the ones stored in the repository, due to different versions of various software components being used. The screenshots taken in this fashion are well suited for visual inspection, but for exact binary comparisons it would be neccessary to carefully set up the environment to match the one used by the Docker approach.

Choosing the list of test cases

Both screenshotter.js and screenshotter.sh will accept an --include option (short -i) which can be used to specify a list of test cases to be processed, as a comma separated list. Conversely, the --exclude option (short -x) can be used to specify a list of cases which are not being processed.

Examples:

node dockers/Screenshotter/screenshotter.js -i Sqrt,SqrtRoot
dockers/Screenshotter/screenshotter.sh --exclude=GreekLetters