Using PHPCompatibilityWP, you can analyse the codebase of a WordPress-based project for PHP cross-version compatibility.

A ruleset for PHP_CodeSniffer to check for PHP cross-version compatibility issues in projects based on the WordPress CMS.

This WordPress specific ruleset prevents false positives from the PHPCompatibility standard by excluding back-fills and poly-fills which are provided by WordPress.

This project needs funding.

The project team has spend thousands of hours creating and maintaining the PHPCompatibility packages. This is unsustainable without funding.

If you use PHPCompatibility, please fund this work by setting up a monthly contribution to the PHP_CodeSniffer Open Collective.

• PHP > 5.4
• PHP_CodeSniffer >= 3.13.3. Use the latest stable release of PHP_CodeSniffer for the best results.
• PHPCompatibility 10.0.0+.
• PHPCompatibilityParagonie 2.0.0+.

The only supported installation method is via Composer.

Composer will automatically install the project dependencies and register the external rulesets with PHP_CodeSniffer using the Composer PHPCS plugin.

Run the following from the root of your project:

composer config allow-plugins.dealerdirect/phpcodesniffer-composer-installer true
composer require --dev phpcompatibility/phpcompatibility-wp:"^3.0@dev"

Next, run:

vendor/bin/phpcs -i

If all went well, you will now see that the PHPCompatibility, PHPCompatibilityWP and some more PHPCompatibility standards are installed for PHP_CodeSniffer.

To upgrade this package, run the following command:

composer update --dev phpcompatibility/phpcompatibility-wp --with-dependencies

You can now use the following command to inspect your code:

vendor/bin/phpcs -p . --standard=PHPCompatibilityWP

By default, you will only receive notifications about deprecated and/or removed PHP features.

To get the most out of the PHPCompatibilityWP standard, you should specify a testVersion to check against. That will enable the checks for both deprecated/removed PHP features as well as the detection of code using new PHP features.

The WordPress minimum PHP requirement was 5.2.4 up to WP 5.1.

• As of WP 5.2, the new minimum PHP requirement is PHP 5.6.20.
• As of WP 6.3, the new minimum PHP requirement is PHP 7.0.0.
• As of WP 6.6, the new minimum PHP requirement is PHP 7.2.24.
• As of WP 7.0, the new minimum PHP requirement is PHP 7.4.0.

To enforce for PHPCompatibility to run against the PHP version you want to support, add --runtime-set testVersion 7.4- to your command-line command or add <config name="testVersion" value="7.4-"/> to your custom ruleset, replacing 7.4- with a testVersion of your choice.

For example:

# For a project which should be compatible with PHP 5.6 and higher:
vendor/bin/phpcs -p . --standard=PHPCompatibilityWP --runtime-set testVersion 5.6-

For more detailed information about setting the testVersion, see the README of the generic PHPCompatibility standard.

By default PHP_CodeSniffer < 4.0 will analyse PHP, JavaScript and CSS files. As the PHPCompatibility sniffs only target PHP code, you can make the run slightly faster by telling PHP_CodeSniffer to only check PHP files, like so:

vendor/bin/phpcs -p . --standard=PHPCompatibilityWP --extensions=php --runtime-set testVersion 5.6-

All code within the PHPCompatibility organisation is released under the GNU Lesser General Public License (LGPL). For more information, visit https://www.gnu.org/licenses/lgpl-3.0.html.