Testing Strategy

Overview

This skill guides agents in selecting and applying appropriate testing strategies for any deliverable. The right testing approach depends on what's being tested, its criticality, and the available time and resources.

When to Use

• Before starting development to define testing approach upfront
• When planning how to verify a deliverable works correctly
• When deciding what types of tests to write and in what order
• When test coverage or quality is questioned
• When introducing a new feature, change, or fix
• Don't use when: Building throwaway prototypes or exploratory proofs of concept

Core Procedures

Step 1: Determine Testing Scope

Ask:

• What is the complexity of the deliverable? (simple/moderate/complex)
• What is the criticality? (low/medium/high/critical)
• Who will use it? (internal team/cross-company/end users)
• What are the failure consequences? (inconvene/degraded/blocked/harmful)

Step 2: Select Testing Layers

Based on scope, select applicable testing layers:

Deliverable Type	Required Testing	Optional
Single function/method	Unit tests	Property-based tests
Module/component	Unit + integration tests	Performance tests
API/Service	Unit + integration + contract tests	Load/security tests
UI/Feature	Unit + E2E tests	Accessibility/usability tests
System/Platform	Integration + E2E + load tests	Security/chaos tests
Data/Analytics	Data validation tests	Accuracy/privacy tests
Prompt/AI output	Functional tests + evaluation tests	Bias/safety tests
Infrastructure	Integration + smoke tests	Chaos/disaster recovery tests

Step 3: Define Test Cases

For each testing layer, define cases covering:

1. Happy Path: Expected inputs produce expected outputs
2. Edge Cases: Boundary conditions, empty/null inputs, maximum values
3. Error Cases: Invalid inputs, missing dependencies, failure modes
4. Regression Cases: Previously discovered bugs, known issues

Step 4: Prioritize Test Execution

Order:

1. Unit tests first (fast, cheap, isolate problems)
2. Integration tests second (verify component interaction)
3. E2E/system tests third (verify full workflow)
4. Performance/security tests as applicable
5. Manual/acceptance tests last

Step 5: Set Coverage Targets

Criticality	Minimum Coverage	Target Coverage
Low	50%	70%
Medium	70%	85%
High	85%	95%
Critical	95%	100%

Quality Checklist

• Testing scope appropriate for complexity and criticality
• All required testing layers included
• Happy path, edge cases, and error cases covered
• Tests are automated where possible
• Coverage targets defined and tracked
• Tests are maintainable (clear, independent, documented)

Error Handling

• Error: Cannot automate a test case Response: Document manual test, explore automation alternatives, flag for future automation
• Error: Tests are too slow to run regularly Response: Separate into fast/slow suites, run fast suite on every change, slow suite on schedule
• Error: Tests are flaky (intermittent failures) Response: Fix or quarantine flaky tests immediately - they undermine confidence in test suite

Cross-Team Integration

Related Skills: test-driven-development, testing-verification, output-validation-checklist, edge-case-analysis Used By: ALL agents writing code or deliverables, especially testing agents (QA teams, Code Reviewers)