phpunit

PHPUnit

Test behavior, not implementation. Tests are executable documentation — if the test name doesn't explain what the code does, rewrite it.

PHPUnit is PHP's standard testing framework. It uses test case classes extending TestCase, setUp()/tearDown() for fixtures, and a full assertion API. All patterns target PHPUnit 11+ on PHP 8.5+. Use PHP 8 attributes exclusively — annotations are deprecated in 11, removed in 12.

References

• Assertion catalog, constraints, exception expectations → [${CLAUDE_SKILL_DIR}/references/assertions.md] — Full assertion API grouped by category, constraint system, custom assertions
• Test doubles — stubs, mocks, MockBuilder → [${CLAUDE_SKILL_DIR}/references/mocking.md] — createStub vs createMock, return config, invocation matchers, argument constraints, MockBuilder
• Data providers — static, named, generators → [${CLAUDE_SKILL_DIR}/references/data-providers.md] — #[DataProvider], #[TestWith], named datasets, generator providers, external providers
• phpunit.xml structure, test suites, source config → [${CLAUDE_SKILL_DIR}/references/configuration.md] — XML elements, strict settings, source element, coverage reports, execution order

Test Structure

Discovery and Naming

• Files: *Test.php in configured test directories. Mirror source structure: src/Service/PaymentService.php → tests/Unit/Service/PaymentServiceTest.php.
• Classes: final class PaymentServiceTest extends TestCase. Always final.
• Methods: test prefix or #[Test] attribute. Describe the behavior: testReturnsEmptyCollectionWhenNoResults not testSearch.
• One test class per production class. Split into Unit/Integration directories.

Arrange-Act-Assert

Structure every test in three phases:

public function testUserCreationSetsDefaults(): void
{
    // Arrange
    $data = ['name' => 'Alice', 'email' => '[email protected]'];

    // Act
    $user = User::fromArray($data);

    // Assert
    $this->assertSame('Alice', $user->getName());
    $this->assertTrue($user->isActive());
    $this->assertSame([], $user->getRoles());
}