KaTeX/dockers/Screenshotter/README.md

How to generate screenshotter images

Automatic generation of screenshots

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:

npm run test:screenshots:update

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.

You can also verify and generate screenshots online using a CI(continuous integration) service. Fork the project, enable CircleCI on your repository, and push your changes. Diffs and generated screenshots are available at build artifacts.

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

How to run screenshotter tests

You can verify screenshots by running:

npm run test:screenshots

or passing --verify option to screenshotter.js or screenshotter.sh. See above for more details.