Pair harmoniously! Working in a pair doesn't mean you've both lost your identity. git-duet helps with blaming/praising by using stuff that's already in git without littering your repo history with fictitous user identities. It does so by utilizing gits commit committer attributes to store the identity of the second pair.

Example:

$ cat <<-EOF > ~/.git-authors
authors:
  jd: Jane Doe; jane
  fb: Frances Bar
email:
  domain: awesometown.local
EOF

$ git duet jd fb
GIT_AUTHOR_NAME='Jane Doe'
GIT_AUTHOR_EMAIL='jane@awesometown.local'
GIT_COMMITTER_NAME='Fraces Bar'
GIT_COMMITTER_EMAIL='f.bar@awesometown.local'

$ touch foo

$ git duet-commit -a -m 'initial commit'
[master (root-commit) ce78563] initial commit
 Author: Jane Doe <jane@awesometown.local>
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 foo

$ git show --format=full
commit ce7856371e3e3a6d05f1b66af96f086df071e783
Author: Jane Doe <jane@awesometown.local>
Commit: Fraces Bar <f.bar@awesometown.local>

    initial commit

    Signed-off-by: Fraces Bar <f.bar@awesometown.local>

diff --git a/foo b/foo
new file mode 100644
index 0000000..e69de29

Options:

0. See releases page for binary downloads, place in your $PATH.
1. Install using Homebrew from the git-duet homebrew tap
2. Build from source (see Building)

Make an authors file with email domain, or if you're already using git pair, just symlink your ~/.pairs file over to ~/.git-authors.

authors:
  jd: Jane Doe; jane
  fb: Frances Bar
email:
  domain: awesometown.local

git duet will use the git pair YAML structure if it has to (the difference is the top-level key being pairs instead of authors) e.g.:

pairs:
  jd: Jane Doe; jane
  fb: Frances Bar
email:
  domain: awesometown.local

If you want your authors file to live somewhere else, just tell git-duet about it via the GIT_DUET_AUTHORS_FILE environmental variable, e.g.:

export GIT_DUET_AUTHORS_FILE=$HOME/.secret-squirrel/git-authors
# ...
git duet jd am

Set two authors (pairing):

git duet jd fb

Set one author (soloing):

git solo jd

Committing (needed to set --signoff and export environment variables):

$ git duet-commit -v [any other git options]

Reverting (needed to set --signoff and export environment variables):

git duet-revert -v [any other git options]

Merging (needed to set --signoff and export environment variables):

git duet-merge -v [any other git options]

Rebasing (needed to set --signoff and export environment variables):

git duet-rebase [any other git options]

Cherry-picking (needed to set --signoff and export environment variables):

git duet-cherry-pick [any other git options]

Suggested aliases:

dci = duet-commit
drv = duet-revert
dmg = duet-merge
drb = duet-rebase
dcp = duet-cherry-pick

Note: git-duet only sets the configuration to use via git duet-commit, git duet-revert, git duet-merge, git duet-rebase and git duet-cherry-pick. Using git solo (or git duet) will not effect the configured user.name and user.email. This allows git commit to be used normally outside of git-duet.

If you're jumping between projects and don't want to think about managing them all individually, you can operate on the global git config:

git solo -g jd
git duet --global jd fb

If you do this habitually, you can set the GIT_DUET_GLOBAL environment variable to true to always operate on the global git config:

export GIT_DUET_GLOBAL=true # consider adding this to your shell profile
git solo jd

You can also set it to false to always operate on the local config, even if the global flag is used.

Sometimes while pairing you want to share the authorship love between the pairs. If you set GIT_DUET_ROTATE_AUTHOR=1 it will swap the author and committer (if there is one) on every git duet-commit (after the commit).

This operates on whichever config the authorship was drawn from (e.g. if the author/committer was set in the repository git config, it will rotate these even if GIT_DUET_GLOBAL is specified).

By default, email addresses are constructed from the first initial and last name ( or optional username after a ;) plus email domain, e.g. with the following authors file:

pairs:
  jd: Jane Doe; jane
  fb: Frances Bar
email:
  domain: eternalstench.bog.local

After invoking:

git duet jd fb

Then the configured email addresses will show up like this:

git config user.email
# -> jane@eternalstench.bog.local
git config duet.env.git-author-email
# -> jane@eternalstench.bog.local
git config duet.env.git-committer-email
# -> f.bar@eternalstench.bog.local

A custom email template may be provided via the email_template config variable. The template should be a valid Go template string (see http://golang.org/pkg/text/template/). The object passed in has .Name, .Username, and .Initials.

Additional functions available to template:

• toLower(s): lowercases string
• toUpper(s): uppercases string
• split(s, d): splits string on delimiter
• replace(s, old, new, n): replaces old in s with new n times (set n to -1 to replace all)

If you need more complex logic, consider using the lookup function described below and awk.

Example:

pairs:
  jd: Jane Doe
  fb: Frances Bar
email_template: '{{with replace .Name " " "-" -1}}{{toLower .}}{{end}}@hamster.local'

After invoking:

git duet jd fb

Then the configured email addresses will show up like this:

git config user.email
# -> jane-doe@hamster.local
git config duet.env.git-author-email
# -> jane-doe@hamster.local
git config duet.env.git-committer-email
# -> frances-bar@hamster.local

If there are any exceptions to either the default format or a provided email_template config var, explicitly setting email addresses by initials is supported.

pairs:
  jd: Jane Doe; jane
  fb: Frances Bar
email:
  domain: awesometown.local
email_addresses:
  jd: jane@awesome.local

Then Jane Doe's email will show up like this:

git solo jd
# ...
git config user.email
# -> jane@awesome.local

Alternatively, if you have some other preferred way to look up email addresses by initials, name or username, just use that instead:

export GIT_DUET_EMAIL_LOOKUP_COMMAND="$HOME/bin/custom-ldap-thingy"
# ... do work
git duet jd fb
# ... observe emails being set via the specified executable

The initials, name, and username will be passed as arguments to the lookup executable. Anything written to standard output will be used as the email address:

$HOME/bin/custom-ldap-thingy 'jd' 'Jane Doe' 'jane'
# -> doej@behemoth.company.local

If nothing is returned on standard output, email construction falls back to the decisions described above.

Since there are multiple ways to determine an author or committer's email, it is important to note the order of precedence used by git-duet:

1. Email lookup executable configured via the GIT_DUET_EMAIL_LOOKUP_COMMAND environmental variable
2. Email lookup from email_addresses in your configuration file
3. Custom email address from Go template defined in email_template in your configuration file (see http://golang.org/pkg/text/template/)
4. The username after the ;, followed by @ and the configured email domain
5. The lower-cased first letter of the author or committer's first name, followed by . followed by the lower-cased last name of the author or committer, followed by @ and the configured email domain (e.g. f.bar@baz.local)

If you'd like to regularly remind yourself to set the solo or duet initials, use git duet-pre-commit in your pre-commit hook:

(in $REPO_ROOT/.git/hooks/pre-commit)

#!/bin/bash
exec git duet-pre-commit

The duet-pre-commit command will exit with a non-zero status if the cached author and committer settings are missing or stale. The default staleness cutoff is 20 minutes, but may be configured via the GIT_DUET_SECONDS_AGO_STALE environmental variable, which should be an integer of seconds, e.g.:

export GIT_DUET_SECONDS_AGO_STALE=60
# ... do work for more than a minute
git commit -v
# ... pre-commit hook fires

If you want to use the default hook (as shown above), install it while in your repo like so:

git duet-install-hook

Don't worry if you forgot you already had a pre-commit hook installed. The git duet-install-hook command will refuse to overwrite it.

In order to have the author and committer properly set when committing via RubyMine, a git wrapper executable may be used to override any executions of git commit. Such an executable is available in the Git Duet repository, and may be installed somewhere in your $PATH like so:

\curl -Ls -o ~/scripts/rubymine-git-wrapper https://raw.github.com/git-duet/git-duet/master/scripts/rubymine-git-wrapper
chmod +x ~/bin/rubymine-git-wrapper

Given an install location of ~/bin/rubymine-git-wrapper as shown above, you would then update your RubyMine setting in Preferences => Version Control => Git to set Path to Git executable to the full path of ~/bin/rubymine-git-wrapper (with the ~ expanded). See issue #8 for more details.

• Running git solo or git duet with no initials outputs configuration in same format as when setting (env variables)
• Does not set user.name and user.email (instead only sets namespaced variables) so that git commit continues to work as normal
• Template format is now Go's text/template

Uses gb for building and vendor management.