rails-schema-merge-driver

A basic Git merge driver for Rails' db/schema.rb top-version conflicts.

This is inspired by this gist, and slightly improved upon.

Installing

1. Grab the merge driver file and save it someplace. This is a Ruby script intended to run in POSIX environments that support hashbang syntaxes and the /usr/bin/env command. In particular, this will not work straight from Cmd or Powershell as-is.
2. Make it executable (e.g. chmod a+x merge-db-schemas-top-version).
3. In a relevant Git attributes file (e.g. $HOME/.config/git/attributes or your project's .git/attributes), add the following:

db/schema.rb merge=railsschema

4. In a relevant Git config file (e.g. $HOME/.gitconfig or your project's .git/config), add the following:

[merge "railsschema"]
  name = Rails schema.db merge driver
  driver = "path/to/the/file" %O %A %B %L %P

(For instance, if you saved the merge driver in /home/tdd/perso/bin, this would read driver = /home/tdd/perso/bin/merge-db-schemas-top-version %O %A %B %L %P).

There! Now you should benefit from this merging for merges and rebases. It likely b0rks on stash applies, tho. Contributions welcome!

Learning more

• git merge-file
• Git attributes
• Custom merge drivers