Symfony Coding Practices

Symfony Coding Practices

Application skill for Symfony official coding standards ingest (awesome-guidelines). Generic PHP: php-coding-practices. PSR layout overlap shared; Symfony adds Yoda, service ids, and exception prose rules.

Core Principle

Symfony PHP reads uniformly, PSR-12 via PHP CS Fixer, Yoda identical compares, strict naming matrix, FQCN service ids, and formatted exception/deprecation messages with MIT headers.

When to Use / NOT

• Symfony components, bundles, apps, and Symfony-style OSS libraries.
• Configuring PHP CS Fixer with Symfony rule set.
• PR review on Symfony contribution or internal bundle.

NOT when:

• Generic PHP without Symfony conventions, php-coding-practices.
• Laravel/WordPress-specific style, stack capsules in skills/*-foundation.
• Runtime Symfony architecture (DI tags, events), framework docs/foundation.

Workflow

1. Structure, spacing, Yoda, control flow, class order (symfony-style-structure-control.md).
2. Naming/services, case matrix, FQCN ids (symfony-style-naming-services.md).
3. PHPDoc/errors, docs, exceptions, license (symfony-style-phpdoc-exceptions.md).
4. Verify, PHP CS Fixer + tests (symfony-style-verify.md).

Red Flags

• php-cs-fixer diff on changed PHP
• Loose == without documented reason
• Literal on RHS in comparisons ($x === 'foo' not Yoda)
• else/elseif after return/throw branch
• break after return in switch case
• Spaces inside array offset brackets
• Missing use import for namespaced class
• camelCase config parameter or route name
• Twig template not snake_case
• Abstract class without Abstract prefix (new code)
• Primary service id not FQCN
• Backticks in exception message
• Exception message missing terminal period
• $obj::class in exception string (use get_debug_type)
• One-line PHPDoc block
• Missing MIT license header before namespace
• void return type on PHPUnit test method

Verification

• vendor/bin/php-cs-fixer fix -v --dry-run on changed paths
• PHPUnit on touched components
• License header on new files
• debug:container for new service ids
• Capsule checklist on exceptions and Yoda compares

References

• awesome-guidelines/references/symfony-style-learning-note.md
• awesome-guidelines/references/symfony-style-structure-control.md
• awesome-guidelines/references/symfony-style-naming-services.md
• awesome-guidelines/references/symfony-style-phpdoc-exceptions.md
• awesome-guidelines/references/symfony-style-verify.md

Related skills

• php-coding-practices, PSR-12, strict_types, DI baseline
• api-design-practices, HTTP API adjacent to Symfony routes
• webappsec-coding-practices, web security on Symfony apps