Chance Digital coding standards

v0.2.0 2018-08-18 22:01 UTC


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This is a codified version of the Chance Digital style guide. We include phpcs and ESLint rules. It is a fork of the similar repository from Human Made.


  1. composer require chancedigital/wp-coding-standards
  2. Run the following command to run the standards checks:
vendor/bin/phpcs --standard=vendor/chancedigital/wp-coding-standards .

The final . here specifies the files you want to test; this is typically the current directory (.), but you can also selectively check files or directories by specifying them instead.

You can add this to your Travis YAML file as a test:

	- phpunit
	- vendor/bin/phpcs --standard=vendor/chancedigital/wp-coding-standards .

Excluding Files

This standard includes special support for a .phpcsignore file (in the future, this should be built into phpcs itself). Simply place a .phpcsignore file in your root directory (wherever you're going to run phpcs from).

The format of this file is similar to .gitignore and similar files: one pattern per line, comment lines should start with a #, and whitespace-only lines are ignored:

# Exclude our tests directory.

# Exclude any file ending with ".inc"

Note that the patterns should match the PHP_CodeSniffer style: * is translated to .* for convenience, but all other characters work like a regular expression.

Patterns are relative to the directory that the .phpcsignore file lives in. On load, they are translated to absolute patterns: e.g. */tests/* in /your/dir/.phpcsignore will become /your/dir/.*/tests/.* as a regular expression. This differs from the regular PHP_CodeSniffer practice.


If you want to add further rules (such as VIP-specific rules), you can create your own custom standard file (e.g. phpcs.ruleset.xml):

<?xml version="1.0"?>
	<!-- Use Chance Digital Coding Standards -->
	<rule ref="vendor/chancedigital/wp-coding-standards" />

	<!-- Add VIP-specific rules -->
	<rule ref="WordPress-VIP" />

You can then reference this file when running phpcs:

vendor/bin/phpcs --standard=phpcs.ruleset.xml .

Excluding/Disabling Checks

You can also customise the rule to exclude elements if they aren't applicable to the project:

<rule ref="vendor/chancedigital/wp-coding-standards">
	<!-- Disable short array syntax -->
	<exclude name="ChanceDigital.Debug.ForceShortArray" />

Rules can also be disabled inline. phpcs rules can be disabled with a // @codingStandardsIgnoreLine comment, and ESLint rules can be disabled with a /* eslint disable ... */ comment.

To find out what these codes are, specify -s when running phpcs, and the code will be output as well. You can specify a full code, or a partial one to disable groups of errors.

Custom ESLint Configuration

This repo comes with an eslintrc.yml file matching the Chance Digital coding standards. While checks can be disabled using the <exclude /> rules, you can't add additional checks this way. Instead, you can create your own ESLint config file.

To enable checking ESLint via phpcs, you need to add the ESLint rule to your custom ruleset:

<rule ref="ChanceDigital.Debug.ESLint" />

ESLint configuration files (.eslintrc.js, .eslintrc.yaml, .eslintrc.yml, .eslintrc.json) will be autodetected by phpcs and used automatically if they exist. Inside your configuration file, you can extend the coding standards lint file by referencing it by a path:

- vendor/chancedigital/wp-coding-standards/.eslintrc.yml

You can also use a custom path and reference this in your ruleset:

<rule ref="ChanceDigital.Debug.ESLint">
		<property name="configFile" value="your/lint/config.yml"/>

Important Note: This must come after the vendor/chancedigital/wp-coding-standards rule, and be a direct child of <ruleset />.

If you're using the ESLint configuration without phpcs, you can simply use chancedigital, as the configuration is published on npm. You can also install this globally (npm install -g @chancedigital/eslint-config-wp) and then use directly on the command line via eslint -c chancedigital .

Included Checks

The phpcs standard is based upon the WordPress-VIP standard from WordPress Coding Standards, with customisation and additions to match our style guide.

phpcs also includes ESLint checking based upon the eslint:recommended standard (checks from this page marked with a check mark), with customisation and additions to match our style guide.

Note: ESLint checks are mapped from ESLint codes to phpcs codes by prefixing with ChanceDigital.Debug.ESLint. e.g. the no-unused-vars ESLint code becomes You need to use the phpcs code when excluding specific rules.


Running tests

To run the tests locally, you'll need the source version of PHP CodeSniffer.

If you haven't already installed your Composer dependencies:

composer install --prefer-source --dev

If you already have, and need to convert the phpcs directory to a source version:

rm -r vendor/squizlabs/php_codesniffer
composer install --prefer-source --dev
composer dump-autoload

Writing sniff tests

To add tests you should mirror the directory structure of the sniffs. For example a test for ChanceDigital/Sniffs/Layout/OrderSniff.php would require the following files:

ChanceDigital/Tests/Layout/OrderUnitTest.php # Unit test code
ChanceDigital/Tests/Layout/ # Code to be tested

Effectively you are replacing the suffix Sniff.php with UnitTest.php.

A basic unit test class looks like the following:


namespace ChanceDigital\Tests\Layout;

use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;

 * Class name must follow the directory structure to be autoloaded correctly.
class OrderUnitTest extends AbstractSniffUnitTest {

	 * Returns the lines where errors should occur.
	 * @return array <int line number> => <int number of errors>
	public function getErrorList() {
		return [
			1  => 1, // line 1 expects 1 error

	 * Returns the lines where warnings should occur.
	 * @return array <int line number> => <int number of warnings>
	public function getWarningList() {
		return [];


Fixture Tests

Rather than testing sniffs individually, FixtureTests.php also tests the files in the tests/fixtures directory and ensures that whole files pass.

To add an expected-pass file, simply add it into tests/fixtures/pass in the appropriate subdirectory/file.

To add an expected-fail file, add it into tests/fixtures/fail in the appropriate subdirectory/file. You then need to add the expected errors to the JSON file accompanying the tested file (i.e. the filename with .json appended). This file should contain a valid JSON object keyed by line number, with each item being a list of error objects:

	"1": [
			"source": "ChanceDigital.Files.FunctionFileName.WrongFile",
			"type": "error"

An error object contains:

  • source: Internal phpcs error code; use the -s flag to phpcs to get the code.
  • type: One of error or warning, depending on the check's severity.