Adding a phpcs.xml file

[dawehner]

It would be kind of nice to ship with a phpcs.xml file. Ideally this would be default at least have the rules be available in core by default, and point to just code running in modules/custom, themes/custom

[gergelypap]

+1

We can use core's ruleset as a starting point: https://github.com/drupal/drupal/blob/8.4.x/core/phpcs.xml.dist

[AlexSkrypnyk]

Since this projects provides tooling via drupal/core-dev, supporting of the configs for that tooling does make sense.

If we decide to do so, we would need to:

1. Add PHPCS configuration to support Coder rules with custom locations as targets.
2. Update CI config to include code standards check using PHPCS

[AlexSkrypnyk]

Config for core development contains a lot of core-specific rules that are not useful for consumer sites.

Here is an example of the config file that can be used in this project (taken from 🌀Vortex Drupal project template and currently used on consumer sites):

<?xml version="1.0"?>
<ruleset name="custom">
    <description>Custom PHPCS Standard, based on Drupal standards.</description>

    <file>web/modules/custom</file>
    <file>web/themes/custom</file>
    <file>web/sites/default/settings.php</file>
    <file>web/sites/default/includes</file>
    <file>tests</file>

    <rule ref="Drupal"/>
    <rule ref="DrupalPractice"/>
    <rule ref="Generic.PHP.RequireStrictTypes" />
    <rule ref="Generic.Debug.ESLint"/>
    <rule ref="PHPCompatibility"/>

    <arg name="extensions" value="inc,info,install,module,php,profile,test,theme,js,css"/>
    <arg name="colors"/>
    <arg value="sp"/>
    <arg name="parallel" value="75"/>

    <!-- Lint code against platform version specified in composer.json key "config.platform.php". -->
    <config name="testVersion" value="8.3"/>

    <!-- Exclude theme assets. -->
    <exclude-pattern>web\/themes\/custom\/.*\/build\/.*</exclude-pattern>
    <exclude-pattern>web\/themes\/custom\/.*\/fonts\/.*</exclude-pattern>
    <exclude-pattern>web\/themes\/custom\/.*\/images\/.*</exclude-pattern>
    <exclude-pattern>web\/themes\/custom\/.*\/node_modules\/.*</exclude-pattern>
    <exclude-pattern>*\.min\.*</exclude-pattern>

    <!-- Force no empty lines after function opening brace. -->
    <rule ref="Squiz.WhiteSpace.FunctionOpeningBraceSpace">
        <type>warning</type>
    </rule>

    <!-- Force no empty lines before control structure closing. -->
    <rule ref="Squiz.WhiteSpace.ControlStructureSpacing.SpacingBeforeClose">
        <type>warning</type>
    </rule>

    <!-- Force no empty lines after control structure closing. -->
    <rule ref="Squiz.WhiteSpace.ControlStructureSpacing.LineAfterClose">
        <type>warning</type>
    </rule>

    <!-- Allow long array lines in tests. -->
    <rule ref="Drupal.Arrays.Array.LongLineDeclaration">
        <exclude-pattern>*.Test\.php</exclude-pattern>
        <exclude-pattern>*.TestCase\.php</exclude-pattern>
        <exclude-pattern>*.test</exclude-pattern>
    </rule>

    <!-- Ignore prefixing of class names with project name in Behat tests. -->
    <rule ref="DrupalPractice.General.ClassName.ClassPrefix">
        <exclude-pattern>*\/tests\/behat\/bootstrap/*\.php</exclude-pattern>
    </rule>
</ruleset>