Good code is like well-built Lego creations - it's strong, looks good, and is easy to change if you need to. The importance of good coding standards is especially high when you're coding in a team, working on a scalable project, or participating in an open-source community like Drupal.  

As with any other open-source project, Drupal has thousands of developers working on the project. And each of them comes with their own level of expertise. How do you ensure everyone on your team or in the community follows good coding practices? Git Hooks!

Git Hooks are an easy and automated way of ensuring your code always meets Drupal’s coding standards. Implementing Drupal Coding Standards with Git hook will help developers to commit and push the code with proper coding standards as declared by the Drupal community. It can also help improve your project management skills and allows developers to commit code with proper commit message standards. Learn more about Git hooks and how to put them into action.

git hooks

What is a Git Hook

Git Hooks are scripts that will run automatically every time a Git command is invoked. Just as you would use hook_form_alter to alter the forms in Drupal, you can have separate pre-defined hooks for every Git action.

git hook

The Pictorial Representation of Git hook

Finding Git hooks

You can find Git hooks within your project folder (provided Git is initialized) under .git/hooks.  There, you will find all the hooks with .sample extension to prevent them from executing by default.

To make use of the required hooks, you need to remove the .sample extension and edit your code for the execution.

There are many Git hooks available but we are going to use pre-commit Git hooks for initiating Drupal coding standards. 

Pre-commit Git hooks are hooks that will run before the code gets committed. It checks for the line of code that's getting committed.

Implementing Git Hooks

Before you start, make sure you have these basic requirements ready:

  • Composer
  • Git
  • Php-code-sniffer
  • drupal/coder:8.3.13

The below procedure is for installing it in Mac devices. You can find the reference link here for installing instructions on other devices.

  • brew install php-code-sniffer
  • composer global require drupal/coder:8.3.13
  • phpcs --config-set installed_paths ~/.composer/vendor/drupal/coder/coder_sniffer
  • phpcs -i  → Will give you installed coding standards.

Let's begin!

I am creating a new Drupal project called demo. You can use it in your existing project as well.

drupal project demo


→ Using cd command we got into the project folder.
     cd demo

→ initializing git into the project
    Git init

→ Adding and making my first commit.
    git commit -m “Initial commit”

Initial commit


→ Installing php code sniffer using below command for Mac.
    brew install php-code-sniffer

auto updated


→ Installing Drupal coder using composer
composer global require drupal/coder:8.3.13

→ Once the coder and its path are defined you will get the following output as shown below image. 
phpcs --config-set installed_paths ~/.composer/vendor/drupal/coder/coder_sniffer

→ phpcs -i
The above command will give you Drupal and DrupalPractice


→ Now you can commit your code. If you have any syntax or coding standard error, you will be notified in the display and your commit process will be aborted.

commit code

→ Below is the code to fix the error automatically

phpcbf --standard=Drupal --extensions=php,module,inc,install,test,profile,theme,css,info,txt,md,yml web/modules/custom/demo

Any other issues will need to be fixed manually. Commit your code once done.

fix error code

Once your code is clean it will allow you to commit the code

test code

Just copy and paste the code in pre-commit.sample within .git/hooks. Don’t forget to remove sample extensions.

Pre-commit code sample:


# Redirect output to stderr.

exec 1>&2

# Color codes for the error message.

redclr=`tput setaf 1`
greenclr=`tput setaf 2`
blueclr=`tput setaf 4`
reset=`tput sgr0`

# Printing the notification in the display screen.

echo  "${blueclr}"
echo "................................. Validating your codes  ……..…………....."
echo "-----------------------------------------------------------${reset}"

# Mentioning the directories which should be excluded.


# Checking for the debugging keyword in the commiting code base.

keywords=(ddebug_backtrace debug_backtrace dpm print_r var_dump  dump console\.log)

keywords_for_grep=$(printf "|%s" "${keywords[@]}")

# Flags for the counter.


# Checking for PHP syntax errors.

changed_files=`git diff-index --diff-filter=ACMRT --cached --name-only HEAD -- | egrep '\.theme$|\.module$|\.inc|\.php$'`
if [ -n "$changed_files" ]
  for FILE in $changed_files; do
  php -l $FILE > /dev/null 2>&1
  if [ $compiler_result -eq 255 ]
    if [ $synatx_error_found -eq 0 ]
      echo "${redclr}"
      echo "# Compilation error(s):"
      echo "=========================${reset}"
    `php -l $FILE > /dev/null`

# Checking for debugging functions.

files_changed=`git diff-index --diff-filter=ACMRT --cached --name-only HEAD -- | egrep -v $dir_exclude`
if [ -n "$files_changed" ]
  for FILE in $files_changed ; do
    for keyword in "${keywords[@]}" ; do

      resulted_files=`git diff --cached $FILE | egrep -x "$pattern"`
      if [ ! -z "$resulted_files" ]
        if [ $debugging_function_found -eq 0 ]
          echo "${redclr}"
          echo "Validating keywords"
          echo "================================================${reset}"
        echo "Debugging function" $keyword
        git grep -n $keyword $FILE | awk '{split($0,a,":");
          printf "\found in " a[1] " in line " a[2] "\n";

# Checking for Drupal coding standards

changed_files=`git diff-index --diff-filter=ACMRT --cached --name-only HEAD -- | egrep -v $dir_exclude | egrep '\.php$|\.module$|\.inc$|\.install$|\.test$|\.profile$|\.theme$|\.js$|\.css$|\.info$|\.txt$|\.yml$'`
if [ -n "$changed_files" ]
    phpcs_result=`phpcs --standard=Drupal --extensions=php,module,inc,install,test,profile,theme,css,info,txt,md,yml --report=csv $changed_files`
  if [ "$phpcs_result" != "File,Line,Column,Type,Message,Source,Severity,Fixable" ]
    echo "${redclr}"
    echo "# Hey Buddy, The hook found some issue(s)."
    echo "---------------------------------------------------------------------------------------------${reset}"
    phpcs --standard=Drupal --extensions=php,module,inc,install,test,profile,theme,css,info,txt,md,yml $changed_files
    echo "<=======> Run below command to fix the issue(s)"
    echo "# phpcbf --standard=Drupal --extensions=php,module,inc,install,test,profile,theme,css,info,txt,md,yml your_custom_module_or_file_path"
    echo “<====================================================>"
    echo "# To skip the Drupal Coding standard issue(s), Please use this commands << git commit -m your commit Message --no-verify >>"
    echo "-----------------------------------------------------------------------------------------------------------------------------------------${reset}"

# Checking for merge conflict markers.

files_changed=`git diff-index --diff-filter=ACMRT --cached --name-only HEAD --`
if [ -n "$files_changed" ]
  for FILE in $files_changed; do

    resulted_files=`egrep -in "$pattern" $FILE`
    if [ ! -z "$resulted_files" ]
      if [ $merge_conflict -eq 0 ]
        echo "${redclr}"
        echo "-----------------------Unable to commit the file(s):------------------------"
        echo "-----------------------------------${reset}"
      echo $FILE

# Printing final result

if [ $errors_found -eq 0 ]
  echo "${greenclr}"
  echo "Wow! It is clean code"
  echo "${reset}"
  echo "${redclr}"
  echo "Please Correct the errors mentioned above. We are aborting your commit."
  echo "${reset}"
  exit 1


Final Thoughts

I hope you found this article interesting and that it helps you write better code because better code means a better web! Liked what you just read? Consider subscribing to our weekly newsletter and get tech insights like this one delivered to your inbox!

E. PrabuMay 23, 2023