Kore Nordmann - PHP / Projects / Politics
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

:Author: 		Kore Nordmann
:Date:			Wed, 16 Sep 2009 17:12:05 +0200
:Revision: 		4
:Copyright:		CC by-sa


================
SVN commit hooks
================

:Description:
  Thomas moderated a discussion during the PHP-Unconference-Hamburg on SVN
  commit hooks. It showed that there is interest in my commit message parser,
  so that I make it available now…

Thomas__ moderated a discussion__ during the `PHP-Unconference-Hamburg`__ on
SVN commit hooks. It showed that there is interest in my commit message parser,
so that I make it available now under New-BSD-license.

I created a SVN repository which contains the commit message parser, a lint
checker and the basic infrastructure for more commit hooks, with the discussed
reporting facilities.

The basic idea
==============

The basic idea is to ensure that all developers in your team follow certain
standards, when contributing code to your project. In some cases some
developers continue to write code which does not follow your coding standards,
sometimes even accidentally commit code, which does not compile, or do not pay
enough attention to their commit messages.

One way to keep your developers thinking about this are commit hooks, for
example in SVN, which reject commits which do not follow the defined standards,
or inform the developer itself, the project manager, or some public list about
violations in a recent commit.

The checks
==========

There are several possible checks, which have been developed and proved
valuable in different projects:

- Simple lint checking

  It ensures that the committed files actually compile. This should be a hard
  criteria for accepting commits, as this might break the checkouts of all
  other developers and thus decrease the productivity.

- Commit message verification

  For arbit__ I implemented a validator for commit messages, which ensures the
  commit messages follow a `defined standard`__. This not only ensures the
  commit messages are parseable later on, but also causes the developers
  paying more attention to the contents of their commit messages. It showed 
  that such checks can noticeably increase the quality of commit messages in 
  projects.

- Code sniffer checks

  Code sniffer can ensure that your code follows your coding standards, each
  method is documented, and so on. It is arguable if you want to prevent code
  from being committed if it does not follow the coding standards, but I think
  you should at least inform the developer in a post-commit-hook.

The implementation
==================

After the discussion on the unconf I quickly hacked together the basic
infrastructure for such checks, so that it fulfills the following goals:

1) Checks should be pluggable and easily configurable

2) The checks should be possible to configure for pre-commit and post-commit
   hooks.

3) For proper reporting on post- and pre-commit-hooks it should be possible to
   configure the reporting accordingly to either send mails, or echo the errors
   to STDOUT for pre-commit-hooks – with future possible custom reporters, of
   course.

The code is available in the following SVN repository, including tests::

    svn://kore-nordmann.de/php-commit-hooks

I also configured a mailing list for the discussion and future deveopment of
those standards – you can subscribe at pch-subscribe@kore-nordmann.de (the ML
itself resides under pch@kore-nordmann.de).

Please test the yet available stuff and join a discussion on the mailing list.
This is at a very early stage of publishing, but I am sure you can deal with
that. :)

__ http://www.a-basketful-of-papayas.net/
__ http://www.php-unconference.de/wiki//index.php?title=PhpUnconf2009SundaySessionA4
__ http://www.php-unconference.de/wiki//index.php?title=Hauptseite
__ http://arbitracker.org/news.html
__ http://tracker.arbitracker.org/arbit/development_wiki/view/CodingGuidelines#commit_messages


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Trackbacks
==========


Comments
========

- Paul at Wed, 23 Sep 2009 18:49:29 +0200

  Hello,

  This project looks interesting.  Can you please contrast it with what can be
  accomplished using a Continuous Integration server such as Xinc
  (http://xinc.googlecode.com)?

  Thanks!

  Paul

- Basilio Vera at Tue, 29 Sep 2009 13:18:50 +0200

  Paul, with this hooks you can forbid commits, with a CI server you are able
  to use the same rules once have been accepted in the repository, and here's
  a subtle difference... With several developers it's very common to have a
  lot of code in repository that violates the rules. ;)

  In our company we are even using Pre-Commit Client hooks (feature providen
  by TortoiseSVN) to check if the UnitTesting is good enough (min asserts
  number, code coverage of 70%) to every class you are trying to commit. ;)

- ornela @ cheap host at Thu, 22 Jul 2010 16:44:05 +0200

  it is very important for larger projects that all developers follow the
  standards. Interesting project.

- Palace 24 at Fri, 27 Aug 2010 11:17:31 +0200

  Thanks for sharing this application here. I needed it for my project. The
  reason i liked it because it is very simple and easy as you told above. I
  admire you for making very simple and useful application..

- Daniel at Tue, 31 Aug 2010 10:41:12 +0200

  Hey Kore, were do I get systemProcess.php from?

- Kore at Tue, 31 Aug 2010 12:17:53 +0200

  The git repository at http://github.com/kore/php-commit-hooks contains a
  makefile, which checks out all dependencies, just type `make init` and
  systemProcess will be automatically fetched.

  Check the Makefile for the repository URL.

- Adam at Mon, 13 Sep 2010 09:03:42 +0200

  very interesting.although as you said,its still early stages,i surely can
  deal with it and needless to say,its gonna be of great help to make sure
  that all developers maintain standards.

- shingles symptoms at Fri, 17 Sep 2010 17:58:45 +0200

  Paul, with this hooks you can forbid commits, with a CI server you are able
  to use the same rules once have been accepted in the repository, and here's
  a subtle difference. With several developers it's very common to have a lot
  of code in repository that violates the rules

- Lupus symptoms at Fri, 24 Sep 2010 15:46:41 +0200

  Thanks for sharing this application here. I needed it for my project. The
  reason i liked it because it is very simple and easy as you told above. I
  admire you for making very simple and useful application

- resignation letter sample at Mon, 01 Nov 2010 11:34:27 +0100

  it is very important for larger projects that all developers follow the
  standards. Interesting project.

- chad weber at Mon, 08 Nov 2010 20:41:17 +0100

  It is really a nice post,although as you said,its still early stages,i
  surely can deal with it and needless to say,its gonna be of great help to
  make sure that all developers maintain standards.

- Sarcoidosis at Fri, 03 Dec 2010 14:06:43 +0100

  I am just making a report for my MBA about SVN commit hooks implementation
  and I was just surfing the internet to find a good reliable source. This is
  a good method described here and fits my project perfectly. Thanks in
  advance.

- Proxy at Mon, 03 Jan 2011 18:57:04 +0100

  I liked the post, the implementation is quite interesting, any updates on
  this?

- Rift Guide at Fri, 04 Mar 2011 22:55:47 +0100

  How does fare against something like xinc or any other Continuous
  Integration server?

- telugu songs at Sun, 06 Mar 2011 17:35:41 +0100

  When Subversion calls the .bat file it does so with no environmental
  variables set, you will therefore have to manually set PATH= so that you do
  not receive "XYZ is not recognised as an internal or external command"
  errors.

- Fatty Liver Cure at Tue, 31 May 2011 11:49:02 +0200

  Very interesting - Kudos ! :)

  For as long as I can remember me and my team had issues with how to prohibit
  tabs from C++ files. At the end we found our solution in a simple Python
  hook script.

  Usually the solutions are right in front of us and we can't see them there
  on teh surface because we are digging to deep...like damping red wine stains
  with white wine to eliminate stains (still can't believe that works :))...

  Anyway, we used a pre-commit hook and then tested it by doing two things:

     1. By setting up a throw away temporary repository as a sandbox 2.
  Finding a way to live test the hook script on teh repository befre it's
  actually installed

  Anyway, some interesting idease in your post...

- Mohan at Wed, 23 Nov 2011 16:16:35 +0100

  Paul, with this hooks you can forbid commits, with a CI server you are able
  to use the same rules once have been accepted in the repository, and here's
  a subtle difference... With several developers it's very common to have a
  lot of code in repository that violates the rules. ;)  
  http://www.staphinfectiononline.com

- Gucci pas cher femme at Tue, 29 Nov 2011 07:19:13 +0100

  jour surpasser son idole et de gagner son Championnat WWE quatrième femme
  en moins de trois years.Yet, le recul, qui est vraiment surpris

- shagu at Mon, 19 Dec 2011 08:07:25 +0100

  here is my script

  #!/bin/sh REPOS=”$1" TXN=”$2" # Make sure that the log message contains
  some text. SVNLOOK=/usr/local/bin/svnlook $SVNLOOK log -t “$TXN”
  “$REPOS” | grep “[A-z a-z]” && exit 0 echo “Please write a log
  message describing the purpose of your changes and then try c ommitting
  again.” 1>&2 exit 1

  (if i need to make or force commands only for cpp files,what logic i should
  follow?)