If you are using Subversion/CVS, you might have come across the issue where multiple developers working on a set of files are committing without any comments.
Subversion’s hook scripts provide a powerful way to associate actions with repository events. For example, the pre-commit hook allows you to check — and possibly abort — a transaction before it actually gets committed. I will provide you now two easy Unix bash scripts that avoid bad developer behaviors:
- The first one “checkCommentNotEmpty.sh” is for checking that nobody submit an empty SVN commit comment
- The second one “checkCommentSyntax.sh” is able to enforce SVN commit comment pattern using regular expressions
Creating and Installing a Hook Script
Your Subversion repository already has some template hook scripts. For example, the pre-commit template is in PATH_TO_REPOS/hooks/pre-commit.tmpl. These templates contain instructions on what the hook script does and what parameters it can expect.
You can hook your own script on the following events
- start-commit Before the commit transaction starts
- pre-commit After the commit transaction starts but before the transaction is committed
- post-commit After the commit transaction completes
- pre-revprop-change Before a revision property is changed Repository Path,
- post-revprop-change: After a revision property is changed Repository Path
- pre-lock: Before the lock being acquired
- post-lock: After the lock being acquired
You’ll find examples in the hook directory named
- post-commit.tmpl
- pre-unlock.tmpl
- post-lock.tmpl
- pre-commit.tmpl
- start-commit.tmpl
- post-revprop-change.tmpl
- pre-lock.tmpl
- post-unlock.tmpl
- pre-revprop-change.tmpl
If you cant find them, brute force your server to locate them
# find / –name pre-commit
or
# locate pre-commit
On Debian you will find them at
/data/svn-repos/{yourRepository}/hooks
Create a file pre-commit with that content, nothing force you to put a huge bash script in pre-commit. In my example below, I prefer to divide pre-commit checks in multiple files. The pre-commit hook gives you a way to catch the transaction before it becomes a revision. Subversion passes this hook two parameters:
- the path to the root of the repository
- the transaction identifier
#!/bin/sh
set -e
/data/svn-repos/{yourRepository}/hooks/checkCommentNotEmpty.sh "$1" "$2"
/data/svn-repos/{yourRepository}/hooks/checkCommentSyntax.sh "$1" "$2" Note that after installation, every commit will run these two scripts. Check your permissions, scripts have to be runnable for the user (www-data on debian)
Avoid empty comment in SVN commits
Save this file in /data/svn-repos/{yourRepository}/hooks/checkCommentNotEmpty.sh
#!/bin/sh
REPOS="$1"
TXN="$2"
SVNLOOK=/usr/bin/svnlook
if [`$SVNLOOK log -t $TXN $REPOS` != ""]; then
echo "" 1>&2
echo "*** Your commit has been blocked because you did not give any log message or your log message was too short." 1>&2
echo "Please write a log message describing the purpose of your changes and then try committing again." 1>&2
exit 1
else
exit 0
fi
Example in Eclipse, if you break the rule
Enforce SVN commit comment pattern using regular expressions
Save this file in /data/svn-repos/{yourRepository}/hooks/checkCommentSyntax.sh
This script use Bash script REGEX capabilities, I check against what could be a typical JIRA issues entry
If any developer try to use a commit statement not starting with for example PRODUCT-xxxx, the commit will be blocked.
#!/bin/sh
REPOS="$1"
TXN="$2"
SVNLOOK=/usr/bin/svnlook
regex="PRODUCT-[0-9]*"
if [[ `$SVNLOOK log -t $TXN $REPOS` =~ ${regex} ]]; then
exit 0
else
echo "" 1>&2
echo "*** Your commit has been blocked because you give an invalid commit comment" 1>&2
echo "Please make your commit comment start with PRODUCT-XXX" 1>&2
exit 1
fi Example in Eclipse, if you break the rule
Want more?
You can automated code reviews with Checkstyle using pre-commit script and so Stop rule-breaking code before it enters your code base!
References
hook_scripts" target="_blank">http://subversion.tigris.org/tools_contrib.htmlhook_scripts List of some Hook scripts examples written in python/bash
