testing-strategies_skill

Overview

This skill provides actionable test design patterns, coverage targets, and practical best practices to build comprehensive, maintainable test suites. It focuses on balancing speed and confidence by recommending targets per code area and clear test types. The guidance applies across languages and frameworks and suits teams aiming to improve quality and reduce regressions.

How this skill works

The skill inspects your codebase needs and recommends coverage targets by code category (critical, business logic, utilities, UI). It prescribes test types—unit, integration, end-to-end—and a repeatable test case pattern (happy path, edge, error, special). It also suggests folder organization and runtime trade-offs so teams can prioritize fast feedback and safe releases.

When to use it

• When creating a new test suite from scratch for a project
• When improving or auditing existing test coverage and quality
• When triaging flaky or failing tests to decide scope and mock strategy
• When planning CI pipelines to balance fast feedback with full verification
• When defining testing responsibilities between devs, QA, and CI

Best practices

• Target 100% coverage for critical code (auth, payments, security) and 80%+ project-wide
• Keep unit tests fast and isolated; mock external dependencies and aim for <1ms per test where feasible
• Use integration tests with real dependencies for component contracts and database interactions
• Limit end-to-end tests to critical user journeys to avoid slow CI cycles
• Organize tests by level (tests/unit, tests/integration, tests/e2e) and mirror production layout
• Write tests for happy paths, edge cases, error conditions, and special values (null, zero, large inputs)

Example use cases

• Designing a CI pipeline that runs unit tests on every commit, integration tests on merge, and e2e nightly
• Prioritizing test coverage for a payment module to reach 100% before release
• Refactoring a legacy module by adding unit and integration tests to prevent regressions
• Reducing flaky tests by converting slow, brittle e2e checks into stable integration tests
• Creating test templates that enforce the four-part case pattern for every new function