drupal-coding-standards

Drupal Coding Standards

Always run PHPCS before committing. Never skip static analysis. Use declare(strict_types=1) in every PHP file. Prefer final classes unless explicitly designed for extension. Avoid deep nesting — use guard clauses and early returns.

Validation Commands

# Check coding standards.
./vendor/bin/phpcs --standard=Drupal,DrupalPractice web/modules/custom/my_module/

# Auto-fix standards issues.
./vendor/bin/phpcbf --standard=Drupal web/modules/custom/my_module/

# Static analysis.
./vendor/bin/phpstan analyse web/modules/custom/my_module/

# Deprecation check.
drupal-check web/modules/custom/my_module/

# Security audit.
composer audit

Required Code Patterns

File Headers

<?php

declare(strict_types=1);

namespace Drupal\my_module;

Class Declaration

/**
 * Manages content operations.
 */
final class ContentManager implements ContentManagerInterface {

Constructor

public function __construct(
  private readonly EntityTypeManagerInterface $entityTypeManager,
  private readonly LoggerInterface $logger,
) {}

Naming Conventions

Element	Convention	Example
Local variables	$snake_case	$user_name
Class properties	$lowerCamelCase	$this->entityManager
Classes	PascalCase	ContentManager
Interfaces	PascalCase + Interface	ContentManagerInterface
Constants	UPPER_SNAKE_CASE	MAX_RETRY_COUNT
Services	module.service_name	my_module.content_manager
Hooks	module_hook_name	my_module_form_alter

Anti-Patterns to Report

Anti-Pattern	Fix
foreach with nested if/break/continue	array_filter/array_map/array_reduce
Deep nesting (3+ levels)	Guard clauses, early returns
Non-final classes without reason	Declare final by default
Getters/setters where public readonly works	Use public readonly
\Drupal:: calls in classes	Constructor dependency injection
PHP json_encode/decode	\GuzzleHttp\Utils::jsonDecode/jsonEncode
"Service" namespace	Use logical groupings
Catching \Exception	Catch narrowest exception type

PHPDoc Standards

/**
 * Loads articles by category.
 *
 * @param int $category_id
 *   The taxonomy term ID.
 * @param int $limit
 *   Maximum number of results.
 *
 * @return \Drupal\node\NodeInterface[]
 *   Array of article nodes.
 *
 * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
 */
public function loadByCategory(int $category_id, int $limit = 10): array {

Module Structure

modules/custom/my_module/
  my_module.info.yml
  my_module.module
  my_module.services.yml
  my_module.routing.yml
  my_module.permissions.yml
  config/
    install/
    schema/
  src/
    Controller/
    Form/
    Plugin/
      Block/
    EventSubscriber/
  tests/
    src/
      Unit/
      Kernel/
      Functional/