Git, TargetProcess and Hashtags

At $job, we're using TargetProcess for our user story and task management. One of the neat things you can do in TP is tag commits to a code repository in such a way that they will link to the task associated with that commit:

#123 This commit is linked to task number 123

In order to get this to work, the hashtag has to be the first thing on the first line of the commit message. Anyone using `git` as their source control should immediately see the problem with this...

...In git commit messages, any line starting with # is considered a comment and is stripped out of the commit message. Quite annoyingly, there's no way to change git's default comment delimiter. Since $job is using Subversion, this isn't a problem except for myself, the lowly git user hobbling along with git-svn.

The solution I've come up with is a two-pronged approach involving changing a default and adding a git-hook.

Firstly, the default --cleanup option on a `git-commit` command strips trailing and leading whitespace lines and all commentary (lines starting with #). So I aliased `git commit` to only worry about the whitespace lines, by adding this to my .gitconfig:

[alias]
    cmt = "commit --cleanup=whitespace""

So now git will leave lines starting with "#" alone. This means I have strip them out myself. This is accomplished with a git commit-msg hook that looks like this:

# Use TargetProcess hashtags to link commits to tasks
# use this in conjunction with --cleanup=whitespace
sed -e 's/^#.*//' -e 's/^@\(#.*\)/\1/' -i $1

The first sed expression strips out comment lines. The second one translates any line that starts with "@#" into one starting with "#". The trick is that it does it after the comment line stripping. So now I can do commits that look like this:

git cmt

# The editor opens and I can type:

@#123 This commit is linked to task number 123
# This is a comment line that will get stripped out
#  So it this

When the commit goes through, voila! A commit message starting with a hashtag that can be picked up by TargetProcess.

Edit 2010-12-16: After experimentation and verification, it turns out the TP can pick up the task id hashtag anywhere in the commit message. So all the above is not really necessary. It's interesting from an educational perspective, though.