Git checkout - autocomplete local branches only

Having Git autocomplete branch names when doing a checkout is super useful. Having the autocomplete hang for 30 seconds because it has to look up all 3000 of the remote branches in a massive repo is not so useful. It's actually pretty frustrating.

My solution: changing the git checkout autocomplete to only look at local branches, while using a git checkoutr alias to preserve the original behaviour (because sometimes it's actually needed).

How it's done:

Define an alias for checkout

We're going to use the same checkout command for the remote checkout, but need to have a different command so the script can differentiate between them. Making an alias does exactly this.

Create the alias by running git config --global alias.checkoutr checkout

Change the autocompletion function

The checkout autocomplete behaviour is defined in a function called _git_checkout in the git autocompletion file. We're going to override the function with our own version that has different autocomplete logic in it.

The location of the file varies over different operating systems and configurations, but here are a few spots to look:

• /etc/bash_completion.d/git
• /usr/share/bash-completion/completions/git

For a brew-installed git autocomplete on macOS, the file will probably be $(brew --prefix)/etc/bash_completion.d/git-completion.bash

Once you've found the file, copy the entire _git_checkout function into your .bashrc (or equivalent non-login shell startup script). Now look for the line

__git_complete_refs $track_opt

We're going to replace that line with:

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if [ "$command" = "checkoutr" ]; then
    __git_complete_refs $track_opt
else
    __gitcomp_direct "$(__git_heads "" "$cur" " ")"
fi

After saving and re-sourcing your .bashrc file, git will autocomplete local branches and tags when using git checkout, but will go back to the default behaviour of autocompleting all references when using git checkoutr.

Credits to a combination of answers on this StackOverflow post.

EDIT 2017-10-02: Updated to work with git v2.13.0 thanks to Alexander Ko's comment.
EDIT 2018-03-24: Updated to speed up branch and tag completion.