> I would maybe be interested in Git allowing you to plug in your own diff generators for different file types.
This is already supported.
This is already supported.
- MS Office: https://github.com/lcnittl/DMFO - SQLite: https://github.com/cannadayr/git-sqlite - Jupyter notebooks: https://nbdime.readthedocs.io/en/latest/vcs.html#git-integra...
One big caveat of this is that since git doesn't really store just a stack of diffs, despite the fact it presents itself as such to the user, a custom merge driver will not make your .git grow any less than it would normally.
>a custom merge driver will not make your .git grow any less than it would normally.
You can go a long way with simple homespun methods. SQL dumps delta-compress in Git very well - especially if you tweak the dump options a bit so that the row order is mostly stable.
The same most probably goes for any other textual dump - if the (unchanged) content is largely ordered in stable fashion, it will delta-compress very well, even without any explicit, specialized support in Git itself.
Note that git does support using deltas for storage. But according to docs, custom diff drivers aren't used for those, instead it's a instruction based format.
https://git-scm.com/docs/pack-format#_deltified_representati...
https://docs.unity3d.com/Manual/SmartMerge.html
Configuring it to work with Git and others is a little ways down the page, but would apply the same for other diff tools.
Here's a proof of concept python merge driver I bashed together at the time to auto-merge JSON objects: https://github.com/fcostin/jsonmerge_git_merge_driver
This never went anywhere near production, but it was very easy to put together something basic.
One complication with using a custom merge driver, as discussed by https://github.com/Praqma/git-merge-driver , is that they need to be configured inside the `.git/config` of the repo, which itself is not version controlled. So there's an additional config management overhead to rolling that out to everyone in a machine. Additionally, if outsourcing hosting for git repos, it may not be supported to install and configure a custom merge driver for merges conducted by the hosting platform (e.g. merges created by github.com pull request workflow).
One idea I had at the time was using external schema files (e.g. JSON schema for JSON files) to help guide/constrain the result of the merge. I never implemented it, but it should be possible. If the schemas were also version controlled in the same git repo that stores the data, you'd need to figure out which one (and which version) to load when resolving a merge conflict of a data file. There doesn't seem to be a well-supported robust way for a merge driver script to discover the source and destination branches, but there are some potentially fragile ways of doing it that work some of the time.