php-testing

name	php-testing
promoted_to	php
description	PHP testing patterns: PHPUnit, test doubles, database testing.
user-invocable	false
context	fork
agent	php-general-engineer
routing	{"triggers":["php testing","phpunit","pest php","php mock"],"category":"php","pairs_with":["php-quality","test-driven-development"]}

PHP Testing Skill

Overview

Apply PHPUnit testing patterns for PHP projects: unit tests with data providers, test doubles (stubs, mocks, Prophecy), database testing (Laravel/Symfony), HTTP testing, and coverage configuration.

See references/patterns.md for full code examples, the failure modes table, and the commands reference.

Reference Loading Table

Signal	Load These Files	Why
writing PHPUnit tests: data providers, mocks/stubs, database or HTTP tests, coverage config	patterns.md	Loads detailed guidance from patterns.md.

Instructions

Phase 1: IDENTIFY

Determine what needs testing:

• Unit logic: use PHPUnit TestCase with test prefix or @test annotation
• Table-driven cases: use @dataProvider static methods
• Collaborator behavior: use stubs (return values only) or mocks (assert interactions)
• Database state: use DatabaseTransactions (Laravel) or KernelTestCase (Symfony)
• HTTP endpoints: use Laravel HTTP helpers or Symfony WebTestCase

Phase 2: WRITE

Write tests following these rules:

• Call parent::setUp() first in every setUp() method
• Use assertSame() instead of assertTrue($a === $b) for meaningful failure messages
• Mock only collaborators and dependencies, never the class under test
• Keep tests independent -- do not use @depends chains
• Extract repetitive cases to @dataProvider rather than duplicating test methods

For test doubles: use createStub() when you only need return values, createMock() when asserting method calls, and Prophecy (phpspec/prophecy-phpunit) for more expressive interaction assertions.

For database tests: use DatabaseTransactions (Laravel) or DoctrineTestBundle (Symfony) to roll back state after each test.

Phase 3: VERIFY

Run the test suite and confirm all tests pass:

./vendor/bin/phpunit

For coverage enforcement:

XDEBUG_MODE=coverage ./vendor/bin/phpunit --coverage-text --coverage-min=80

GATE: All tests pass. Coverage threshold met if configured. No failure modes from references/patterns.md introduced.