php-testing-patterns

name	php-testing-patterns
description	Use when writing or reviewing PHP tests - PHPUnit assertions, WordPress test utilities (WP_UnitTestCase, factories), WooCommerce test patterns, and Brain Monkey isolation.

PHP Testing Patterns

PHPUnit, WordPress, and WooCommerce testing patterns. For shared test quality principles (philosophy, smells, mocking decisions), see testing-patterns.

Reference Routing

Need	Reference File	Sections to Read
PHPUnit + WordPress + WooCommerce patterns	${CLAUDE_SKILL_DIR}/../testing-patterns/references/phpunit-patterns.md	Full file (~422L, manageable)
Behavior vs implementation	${CLAUDE_SKILL_DIR}/../testing-patterns/references/test-philosophy.md	## The Fundamental Shift + ## Four Core Principles
Flaky/brittle tests	${CLAUDE_SKILL_DIR}/../testing-patterns/references/test-smells.md	## The Six Major Test Smells (relevant subsection)
Mock usage decisions	${CLAUDE_SKILL_DIR}/../testing-patterns/references/mocking-strategies.md	## The Mocking Decision Framework
AAA pattern/naming	${CLAUDE_SKILL_DIR}/../testing-patterns/references/test-structure.md	## The AAA Pattern + ## Test Naming Conventions
Test data strategy	${CLAUDE_SKILL_DIR}/../testing-patterns/references/test-data.md	## Factories + ## Builders

How to read sections: Grep for heading to find line number, Read with offset+limit.

PHP Assertion Quick Reference

Use	Instead Of	Why
assertSame($expected, $actual)	assertEquals()	Strict type comparison — assertEquals('1', 1) passes silently
assertCount(3, $items)	assertSame(3, count($items))	Better failure messages
assertInstanceOf(Foo::class, $obj)	assertTrue($obj instanceof Foo)	Better failure messages
assertStringContainsString()	assertTrue(strpos(...) !== false)	Readable, descriptive
@dataProvider	Duplicated test methods	DRY, parameterized, each case is a named data set
$this->factory->post->create()	wp_insert_post()	WordPress factory handles cleanup
expectException(E::class)	try/catch + fail()	PHPUnit native exception testing

PHP Red Flags

Pattern	Why Harmful	Fix
assertTrue(true)	No assertion at all	Add meaningful assertion
assertEquals over assertSame	Type coercion hides bugs	Use assertSame
Missing @dataProvider	Duplicated test logic	Extract data provider
Direct DB queries in unit tests	Slow, fragile	Use WordPress factories
setUp() without parent::setUp()	WP state not initialized	Add parent::setUp()
Mocking owned classes	Design smell	Refactor for loose coupling
Missing tearDown() cleanup	State leaks	Restore globals, remove filters
wp_insert_post() in unit tests	No automatic cleanup	Use $this->factory->post->create()

WordPress Test Utilities

• WP_UnitTestCase — base class with DB transactions, factory access, assertion helpers
• Factories — $this->factory->post, ->user, ->term, ->comment with create() and create_and_get()
• Brain Monkey — isolate WordPress functions in true unit tests (Functions\when('get_option')->justReturn('value'))
• WC_Unit_Test_Case — WooCommerce base class with product/order helpers