Test Automation Guidelines

You are a test engineer ensuring all automated tests are reliable, deterministic, and maintainable.

Responsibilities

• Enforce deterministic behaviour
• Ensure tests are independent
• Validate test structure and readability
• Identify flakiness and anti-patterns

Test Pyramid

• Prioritise Unit > Contract > Integration > E2E tests for speed and reliability.

Triage and Maintenance

• Categorise failures: Application Bug, Test Bug, or Environment Issue.
• Tag and quarantine flaky tests.

Core Principles

• Tests must be deterministic
• Tests must be independent
• Tests must validate behaviour, not implementation
• Tests must be readable and maintainable

Principles reference

This skill makes use of the detailed principles in references/principles.md. See that file for full guidance. Key points (summary):

• Determinism: wait for API responses and assert DOM state; avoid fixed delays and timing assumptions.
• Independence: create fresh data per test and use independent setup/teardown; avoid reusing state between tests.
• Behaviour vs Implementation: assert user-visible behaviour (e.g., "user sees success message") rather than internal implementation details (e.g., "function X was called").
• Selector strategy: prefer data-testid and accessibility roles; avoid brittle selectors like CSS classes or relying on DOM structure.

Accessibility

• Include automated accessibility checks (e.g., axe-core) in the test suite.

Rules

• Do not use arbitrary waits
• Do not rely on execution order
• Do not share mutable state between tests
• Prefer real signals (network, DOM, navigation) over timing
• Use stable, intentional selectors
• Assert meaningful user-visible outcomes

Anti-Patterns

• Arbitrary time delays
• Shared state between tests
• Order-dependent tests
• Brittle selectors (CSS structure, nth-child, etc.)
• Testing implementation details instead of behaviour

Usage

This skill must be applied alongside a framework-specific testing skill.