# PHP Standard

> Activate when writing, reviewing, or testing PHP code to enforce clean code, strict typing, and PHPUnit standards.

- Skill: `didacrios/php-standard` (Agent Skill)
- Install (CLI): `npx skillmds@latest add didacrios/php-standard`
- Raw SKILL.md: https://api.skillmd.com/api/skills/didacrios/php-standard/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: didacrios (https://skillmd.com/u/didacrios)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/didacrios/php-standard

---


# PHP & Testing Standards

Language-specific rules for PHP projects covering strict typing, PSR compliance, clean architecture, and PHPUnit testing conventions.

## When to Activate
- Writing or modifying PHP code (>= 8.2)
- Creating or updating PHPUnit tests
- Reviewing PHP code for standards compliance
- Setting up PHP project architecture

## Core Concepts
- **Strict typing everywhere** — `declare(strict_types=1)` in every file
- **PSR compliance** — PSR-12 coding style, PSR-4 autoloading
- **Value Objects** — domain concepts modeled as immutable objects
- **TDD flow** — one test at a time, written before the implementation

## Detailed Guidance

### Environment & Constraints
- **PHP Version:** Target >= 8.2. Use modern features (Readonly properties, Enums, Constructor Promotion) where applicable.
- **Strict Typing:** Always include `declare(strict_types=1);` at the top of every file.
- **PSR Standards:** Adhere strictly to PSR-12 (Coding Style) and PSR-4 (Autoloading).

### Clean Code & Architecture
- **Method Size:** Methods must be between 10 and 20 lines max.
- **Abstractions:** Use Value Objects for domain concepts (Email, Price, Id).
- **Inversion of Control:** Dependencies must be injected via constructor, preferably using promoted properties.

### Testing Protocol (PHPUnit)
- **Framework:** PHPUnit.
- **TDD Flow:** Create exactly one test before implementing the logic.
- **Naming:** `test[FunctionName]_[Scenario]_[ExpectedResult]`.
- **Structure:** Use **Given-When-Then** comments.

### Test Maintainability
- **Object Mother:** Use for complex entities.
- **Data Providers:** Use `@dataProvider` to keep tests DRY when testing multiple cases.
- **Location:** `tests/` mirroring `src/`.

### Recursive Verification
- **Autoloading:** Check `composer.json` or directory structure to ensure correct namespaces.
- **Type Tracing:** If a method returns a class, peek into that class to understand its structure before using the return value.

## Examples

**Test structure:**
```php
public function testCreateUser_WithValidData_ReturnsUser(): void
{
    // Given
    $email = EmailMother::random();
    // When
    $user = $this->service->create($email);
    // Then
    $this->assertEquals($email, $user->email());
}
```

## Guidelines
1. `declare(strict_types=1)` in every PHP file — no exceptions
2. PSR-12 coding style and PSR-4 autoloading
3. Methods between 10-20 lines; extract if longer
4. Value Objects for domain concepts (Email, Price, Id)
5. Constructor injection with promoted properties
6. One test before one implementation — no batch writing
7. Test naming: `test[Function]_[Scenario]_[Expected]`
8. Object Mother pattern for complex test entities
9. `@dataProvider` for multi-case tests

## Integration
- Related: `recursive-exploration` (reasoning model), `refactor` (cleanup workflow), `code-review` (review checklist)

## Skill Metadata
- Created: 2025-06-01
- Last Updated: 2025-07-01
- Author: didacrios
- Version: 1.0.0