Setting Up A PHP CodeSniffer For WordPress using Composer

A PHP CodeSniffer is a program that helps developers keep code clean and uniform or in sync across teams. In PHP, you can easily set up a code sniffer program to help lint and watch your files while you work and ensure that you keep to standards with everyone in the team.

Let’s get started.

Step 1. Install Composer

The first thing would be to ensure you have Composer installed on your computer. No point going forward if you don’t have that installed. You can install Composer on your computer using Homebrew like so:

brew install composer        

Step 2.?Install PHPCS

Next would be to install PHPCS (PHP CodeSniffer) globally on your Computer terminal using Composer like so:

composer global require squizlabs/php_codesniffer        

Step 3. Expose PHPCS to system $PATH

To ensure you can access PHPCS globally or anywhere on your computer, you need to expose it to the PATH environment variable on your computer by adding the following line to the .zshrc or .bashrc file found on your root folder:

export PATH="$PATH:$HOME/.composer/vendor/squizlabs/php_codesniffer/bin"        

If you're not sure where to find your .zshrc or .bashrc file, you can type the following command on your terminal:

cd ~ && ls -al        

It will take you to your root folder and display all the files in your root folder (including the hidden ones).

Step 4. Confirm PHPCS

Once the above step is completed, we need to ensure that the PHPCS is installed properly and accessible on your terminal, type in the following command:

phpcs -i        

You should see something similar to this:

The installed coding standards are MySource, PEAR, PSR1, Squiz, Zend        

Step 5. Install WP Coding Standard

Next, we install WP Coding standards as a global dependency. This will enable us get access to the WP coding standards package via composer like so:

composer global require wp-coding-standards/wpcs        

Step 6. Clone PHP Compatibility Git Repo

We'll also need to clone the PHP Compatibility Git repo into our .composer vendor bin folder like so:

cd ~/.composer/vendor && git clone https://github.com/wimg/PHPCompatibility.git        

Step 7. Configure PHPCS Paths

Now that you have WP Coding Standards and PHP Comptability installed successfully, all that's left is to configure the PHPCS paths like so:

phpcs --config-set installed_paths $HOME/.composer/vendor/PHPCompatibility, $HOME/.composer/vendor/wp-coding-standards/wpcs        

Now run the following command on your terminal:

phpcs -i        

You should see something similar to this:

The installed coding standards are MySource, PEAR, Zend, Squiz, PSR1, PHPCompatibility, WordPress-VIP, WordPress, WordPress-Extra, WordPress-Docs and WordPress-Core        

Congratulations!!!

You're now all set up to start using PHPCS to lint your PHP files in your WordPress projects.

How to use PHPCS

To use PHPCS in your WP plugin or theme repo, you have to ensure your WP plugin or theme repo has a phpcs.xml set up with WP rulesets defined.

Here's an example of an Auttomatic's phpcs.xml with WP rulesets defined:

https://github.com/Automattic/_s/blob/master/phpcs.xml.dist        

Copy the code in the above XML file and save it into your own phpcs.xml file in the root path of your WP project. Now, you are ready to run your PHPCS and PHPCBF commands.

To sniff for errors in your WP project, run the following command on your terminal like so:

phpcs        

To fix errors in your PHP files you can type the following command on your terminal like so:

phpcbf        

Hope this helps in your WP projects. Please leave a comment below, thanks.