We are currently in the process of converting the Math renderer from
JS to PHP. In this context, we deal with large (50Mb) files for
testing https://phabricator.wikimedia.org/T315223. While the test file
was part of the JS source code repo, we are unsure if this is also the
best practice for PHP code, as I don't remember having seen that in
other repositories such as core.
If you have experience with this, please let me know.