PHP Testing

Priority: P1 (HIGH)

Structure

tests/
├── Unit/
├── Integration/
└── Feature/

Implementation Guidelines

• Standards: Use

  PHPUnit

  (9/10+) or

  Pest

  . Organize into

  Unit/

  ,

  Integration/

  , and

  Feature/

  . Class names should extend

  TestCase

  (e.g.,

  class OrderServiceTest extends TestCase

  ).
• TDD Workflow: Follow Red-Green-Refactor. Red: write failing test first for

  createOrder()

  , then Green: implement minimal logic to pass, then Refactor.
• Mocking: Use

  createMock(PaymentService::class)

  for dependencies. Define behavior with

  expects($this->once())

  and

  method('charge')

  with

  with(100)->willReturn(true)

  . DO NOT mock simple Data Objects.
• Fluent Assertions:

  assertSame checks type + value

  (

  ===

  ) — use

  assertSame('Test', $result->title)

  over

  assertEquals

  to avoid type coercion surprises. Also use

  assertCount()

  and

  assertMatchesRegularExpression()

  .
• Data Providers: Use

  #[DataProvider('statusProvider')]

  (PHPUnit 10+) with a

  public static function statusProvider(): array

  or

  dataset

  (Pest).
• Isolation: Ensure tests are Independent and Repeatable. DB tests must use

  Transactions

  or

  SQLite :memory:

  .
• Pest syntax: Use

  it('creates an order', function() { ... })

  and

  expect($result->title)->toBe('Test')

  for cleaner, more readable tests.
• Coverage: Aim for

  80%+

  line coverage. Use

  phpunit.xml

  to whitelist specific directories.
• Automation: Run tests on every PR using GitHub Actions or GitLab CI.

Anti-Patterns

• No testing private methods: Test through public interfaces only.
• No over-mocking internals: Mock only external boundaries.
• No real network/DB in unit tests: Use in-memory databases or mocks.
• No coverage-metric chasing: Prioritize meaningful assertions.

References

• Testing Patterns & Mocks