How to use Git Hooks to save some time

Who am I?

Marian HackMan Marinov

@OpenFest
@турнето
Chairman of Open Projects Foundation
CEO & Co-founder of 1H Ltd.
Part time lecturer at FMI and Telerik


What is git?

                 [ my repo ] <-----> [ central ]
                    |   \
                    |    \ <----> [ stefan ]
   [ github ] <---> /

What is a git hook?

 A simple script

And what types of hooks do we have?
  pre-commit
  prepare-commit-msg
  commit-msg [--no-verify]
  post-commit
  post-checkout
  post-merge
  pre-receive
  post-receive


My pre-commit
#!/bin/bash

change=($(git diff --name-status --cached))
st=${change[0]}
name=${change[1]}

function err() {
	echo -n "\nThere is an issue with the committed"
	echo -e "file: \e[31m$1\e[0m\n"
	echo "Please fix it before trying to commit again."
	exit 1
}

######
# Handle only files that are changed or newly added
######
if [ "$st" != 'M' ] && [ "$st" != 'A' ];  then
	exit 0
fi

######
# Bash syntax checks
######
if [[ "$name" =~ \.sh$ ]] && ( ! bash -n $name ); then
	err $name
fi

######
# Perl handling
######
if [[ "$name" =~ \.pl$ ]]; then
	# Syntax checks
	if ( ! perl -c $name ); then
		err $name
	fi
	# Indentify the code
	# -syn   - syntax checks
	# -dws   - remove trailing white spaces
	# -et=4  - replace every 4 spaces with one tab
	# -bbs   - blank lines before subs and packages
	# -ce    - cuddled else; } else {
	if ( ! perltidy -syn -dws -et=4 -bbs -ce $name ); then
		err $name
	fi
	if [ -f ${name}.tdy ] && ( ! diff $name ${name}.tdy > /dev/null ); then
		/bin/mv -f ${name}.tdy $name
	fi
	# Produce some major critics about the code
	if ( ! perlcritic -2 $name ); then
		err $name
	fi
fi

######
# PHP handling
######
if [[ "$name" =~ \.pl$ ]]; then
	# Syntax checks
	if ( ! php -l $name ); then
		err $name
	fi
fi

exit 0

What else can I do with hooks:
* prepare-commit-msg / commit-msg
 - Auto format your commit messages
 - Add additional information into the commit, 
	like signatures
 - Add third party CC for the patch(to be used 
	by post-receive-email)

* post-commit
 - auto generate patches or patch sets
 - auto push to default and non default remotes

* post-checkout
 - fast deployment
	deploy everything in a separate branch and 
	switch to it later
 - reconfigure your local copy

* pre-receive
 - check the incoming data 
  verify that there is no malicious code
  syntax checks

* post-receive
 - Run code tests
  have a separate directory and make a pull in that 
  dir and start test
 - Upload your project to the live environment
  pull the uploaded data directly into the live 
  environment 
 - Very fast deploy to live
  pull the new changes in a separate branch and 
  switch to it
 - Update changes to your database
 - Use post-receive-email to send e-mail notifications
 - Auto push to other remotes

 /usr/share/git-core/contrib/hooks/post-receive-email
 [hooks]
	mailinglist = mm@1h.com
	emailprefix = [GIT]  
 project/description

How can you make use of the hooks for different languages:
* Do syntax checks
 - bash -n
 - perl -c
 - ruby -c
 - php -l
 - python -m py_compile

* Do Indentation
 - beautify_bash
 - Perl::Tidy
 - PHP Tidy
 - PythonTidy, untabify.py, reindent.py

* Do sanity checks
 - Bash - checkbashisms
 - Perl::Critic
 - Python - pep8, pyflakes