testing-standards_skill

Overview

This skill documents PHPUnit testing conventions and practical best practices for any PHP project. It focuses on test structure, naming, assertions, test doubles, organization, coverage, and Docker-based execution to ensure reliable, maintainable test suites. Use it as a reference to standardize tests across teams and frameworks.

How this skill works

The skill lays out concrete patterns and examples: class structure with setUp/tearDown, AAA and Given-When-Then patterns, data providers, and mock/stub/spy usage. It prescribes assertion choices, documentation practices, test grouping, coverage annotations, and a strict skipped-test policy. It also enforces Docker-based execution and provides a pre-execution checklist for consistent environments.

When to use it

• When establishing or auditing PHPUnit test standards for a project or team
• When writing new unit, integration, or functional tests
• When introducing CI/CD and coverage requirements
• When troubleshooting flaky tests or inconsistent test environments
• When onboarding developers to project testing conventions

Best practices

• Name tests descriptively and test one behavior per test (use testMethodScenario or @test style)
• Follow Arrange-Act-Assert or Given-When-Then patterns to keep tests readable
• Prefer data providers for repetitive cases and keep fixtures small and focused
• Use mocks, stubs, and spies appropriately: mock interactions, stub returns, spy side effects
• Document tests and classes with clear PHPDoc and @covers annotations for coverage accuracy
• Run tests inside Docker containers and maintain a pre-execution checklist to avoid environment drift

Example use cases

• Unit testing a service with repository mocks to verify interaction and returned data
• Using data providers to validate multiple email formats or input permutations
• Integration tests for repositories and database behavior under Dockerized test DB
• Functional API tests that exercise end-to-end flows with clear grouping (unit/integration/functional)
• Enforcing coverage by adding @covers and ignoring legacy code with @codeCoverageIgnore only when necessary