WordPress Coding Standards for PHP_CodeSniffer

• Introduction
• Minimum Requirements
• Installation
  • Composer Project-based Installation
  • Composer Global Installation
  • Updating your WordPressCS install to a newer version
  • Using your WordPressCS install
• Rulesets
  • Standards subsets
  • Using a custom ruleset
  • Customizing sniff behaviour
  • Recommended additional rulesets
• How to use
  • Command line
  • Using PHPCS and WordPressCS from within your IDE
• Running your code through WordPressCS automatically using Continuous Integration tools
• Fixing errors or ignoring them
  • Tools shipped with WordPressCS
• Contributing
• Funding
• License

Introduction

This project is a collection of PHP_CodeSniffer rules (sniffs) to validate code developed for WordPress. It ensures code quality and adherence to coding conventions, especially the official WordPress Coding Standards.

This project needs funding. Find out how you can help.

Minimum Requirements

The WordPress Coding Standards package requires:

• PHP 5.4 or higher with the following extensions enabled:
  • Filter
  • libxml
  • Tokenizer
  • XMLReader
• Composer

For the best results, it is recommended to also ensure the following additional PHP extensions are enabled:

• iconv
• Multibyte String

Installation

As of WordPressCS 3.0.0, installation via Composer using the below instructions is the only supported type of installation.

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

If you are upgrading from an older WordPressCS version to version 3.0.0, please read the Upgrade guide for ruleset maintainers and end-users first!

Composer Project-based Installation

Run the following from the root of your project:

composer config allow-plugins.dealerdirect/phpcodesniffer-composer-installer true
composer require --dev wp-coding-standards/wpcs:"^3.0"

Composer Global Installation

Alternatively, you may want to install this standard globally:

composer global config allow-plugins.dealerdirect/phpcodesniffer-composer-installer true
composer global require --dev wp-coding-standards/wpcs:"^3.0"

Updating your WordPressCS install to a newer version

If you installed WordPressCS using either of the above commands, you can upgrade to a newer version as follows:

# Project local install
composer update wp-coding-standards/wpcs --with-dependencies

# Global install
composer global update wp-coding-standards/wpcs --with-dependencies

Using your WordPressCS install

Once you have installed WordPressCS using either of the above commands, use it as follows:

# Project local install
vendor/bin/phpcs -ps . --standard=WordPress

# Global install
%USER_DIRECTORY%/Composer/vendor/bin/phpcs -ps . --standard=WordPress

Pro-tip: For the convenience of using phpcs as a global command, use the Global install method and add the path to the %USER_DIRECTORY%/Composer/vendor/bin directory to the PATH environment variable for your operating system.

Rulesets

Standards subsets

The project encompasses a super-set of the sniffs that the WordPress community may need. If you use the WordPress standard you will get all the checks.

You can use the following as standard names when invoking phpcs to select sniffs, fitting your needs:

• WordPress - complete set with all of the sniffs in the project
  • WordPress-Core - main ruleset for WordPress core coding standards
  • WordPress-Docs - additional ruleset for WordPress inline documentation standards
  • WordPress-Extra - extended ruleset with recommended best practices, not sufficiently covered in the WordPress core coding standards
    • includes WordPress-Core

Using a custom ruleset

If you need to further customize the selection of sniffs for your project - you can create a custom ruleset file.

When you name this file either .phpcs.xml, phpcs.xml, .phpcs.xml.dist or phpcs.xml.dist, PHP_CodeSniffer will automatically locate it as long as it is placed in the directory from which you run the CodeSniffer or in a directory above it. If you follow these naming conventions you don't have to supply a --standard CLI argument.

For more info, read about using a default configuration file. See also the provided WordPressCS phpcs.xml.dist.sample file and the fully annotated example ruleset in the PHP_CodeSniffer documentation.

Customizing sniff behaviour

The WordPress Coding Standard contains a number of sniffs which are configurable. This means that you can turn parts of the sniff on or off, or change the behaviour by setting a property for the sniff in your custom [.]phpcs.xml[.dist] file.

You can find a complete list of all the properties you can change for the WordPressCS sniffs in the wiki.

WordPressCS also uses sniffs from PHPCSExtra and from PHP_CodeSniffer itself. The README for PHPCSExtra contains information on the properties which can be set for the sniff from PHPCSExtra. Information on custom properties which can be set for sniffs from PHP_CodeSniffer can be found in the PHP_CodeSniffer wiki.

Recommended additional rulesets

PHPCompatibility

The PHPCompatibility ruleset and its subset PHPCompatibilityWP come highly recommended. The PHPCompatibility sniffs are designed to analyse your code for cross-version PHP compatibility.

The PHPCompatibilityWP ruleset is based on PHPCompatibility, but specifically crafted to prevent false positives for projects which expect to run within the context of WordPress, i.e. core, plugins and themes.

Install either as a separate ruleset and run it separately against your code or add it to your custom ruleset, like so:

<config name="testVersion" value="7.0-"/>
<rule ref="PHPCompatibilityWP">
    <include-pattern>*\.php$</include-pattern>
</rule>

Whichever way you run it, do make sure you set the testVersion to run the sniffs against. The testVersion determines for which PHP versions you will receive compatibility information. The recommended setting for this at this moment is 7.0- to support the same PHP versions as WordPress Core supports.

For more information about setting the testVersion, see:

• PHPCompatibility: Sniffing your code for compatibility with specific PHP version(s)
• PHPCompatibility: Using a custom ruleset

VariableAnalysis

For some additional checks around (undefined/unused) variables, the VariableAnalysis standard is a handy addition.

VIP Coding Standards

For those projects which deploy to the WordPress VIP platform, it is recommended to also use the official WordPress VIP coding standards ruleset.

How to use

Command line

Run the phpcs command line tool on a given file or directory, for example:

vendor/bin/phpcs --standard=WordPress wp-load.php

Will result in following output:

--------------------------------------------------------------------------------
FOUND 6 ERRORS AND 4 WARNINGS AFFECTING 5 LINES
--------------------------------------------------------------------------------
  36 | WARNING | error_reporting() can lead to full path disclosure.
  36 | WARNING | error_reporting() found. Changing configuration values at
     |         | runtime is strongly discouraged.
  52 | WARNING | Silencing errors is strongly discouraged. Use proper error
     |         | checking instead. Found: @file_exists( dirname(...
  52 | WARNING | Silencing errors is strongly discouraged. Use proper error
     |         | checking instead. Found: @file_exists( dirname(...
  75 | ERROR   | Overriding WordPress globals is prohibited. Found assignment
     |         | to $path
  78 | ERROR   | Detected usage of a possibly undefined superglobal array
     |         | index: $_SERVER['REQUEST_URI']. Use isset() or empty() to
     |         | check the index exists before using it
  78 | ERROR   | $_SERVER['REQUEST_URI'] not unslashed before sanitization. Use
     |         | wp_unslash() or similar
  78 | ERROR   | Detected usage of a non-sanitized input variable:
     |         | $_SERVER['REQUEST_URI']
 104 | ERROR   | All output should be run through an escaping function (see the
     |         | Security sections in the WordPress Developer Handbooks), found
     |         | '$die'.
 104 | ERROR   | All output should be run through an escaping function (see the
     |         | Security sections in the WordPress Developer Handbooks), found
     |         | '__'.
--------------------------------------------------------------------------------

Using PHPCS and WordPressCS from within your IDE

The wiki contains links to various in- and external tutorials about setting up WordPressCS to work in your IDE.

Running your code through WordPressCS automatically using Continuous Integration tools

• Running in GitHub Actions
• Running in Travis

Fixing errors or ignoring them

You can find information on how to deal with some of the more frequent issues in the wiki.

Tools shipped with WordPressCS

Since version 1.2.0, WordPressCS has a special sniff category Utils.

This sniff category contains some tools which, generally speaking, will only be needed to be run once over a codebase and for which the fixers can be considered risky, i.e. very careful review by a developer is needed before accepting the fixes made by these sniffs.

The sniffs in this category are disabled by default and can only be activated by adding some properties for each sniff via a custom ruleset.

At this moment, WordPressCS offer the following tools:

• WordPress.Utils.I18nTextDomainFixer - This sniff can replace the text domain used in a code-base. The sniff will fix the text domains in both I18n function calls as well as in a plugin/theme header. Passing the following properties will activate the sniff:
  • old_text_domain: an array with one or more (old) text domain names which need to be replaced;
  • new_text_domain: the correct (new) text domain as a string.

Contributing

See CONTRIBUTING, including information about unit testing the standard.

Funding

If you want to sponsor the work on WordPressCS, you can do so by donating to the PHP_CodeSniffer Open Collective.

License

See LICENSE (MIT).