Skill: Test Strategy

What This Skill Does

Creates a test strategy document that answers: what should we test, how, and in what priority? Analyzes the codebase to produce a structured testing plan rather than ad-hoc test writing.

When to Use

• Before starting a testing initiative
• When the user says "we need better test coverage"
• As input for add-tests (which tests to generate first)
• When onboarding a project with poor test coverage

Execution Model

• Phase 1: primary agent analyzes codebase structure, existing tests, and coverage.
• Phase 2: primary spawns doc-explorer to write the strategy document to docs/test-strategy.md.

Workflow

Step 1: Inventory Existing Tests

Map what tests exist:

# Count test files vs source files
find . -name "*.test.*" -o -name "*.spec.*" -o -name "test_*" | wc -l
find . -name "*.ts" -o -name "*.py" -o -name "*.go" | grep -v test | grep -v node_modules | wc -l

For each module, check if a corresponding test file exists.

Step 2: Categorize Modules by Risk

Assess each module's testing priority:

Risk Factor	Weight
Handles user input / external data	High
Has complex business logic	High
Manages state / data persistence	High
Has many dependents (widely imported)	Medium
Performs I/O (file, network, DB)	Medium
Is pure utility / helper	Low

Step 3: Identify Coverage Gaps

For each module:

• Does it have any tests? (binary check)
• Do tests cover happy path? Error cases? Edge cases?
• Are integration points tested?

Step 4: Recommend Test Types

Per module, recommend the appropriate test types:

Module Type	Recommended Tests
Business logic	Unit tests with edge cases
API endpoints	Integration tests
UI components	Component/snapshot tests
Data layer	Integration tests with test DB
Utilities	Unit tests
CLI	Integration tests

Step 5: Generate Strategy Document

Write to docs/test-strategy.md:

# Test Strategy

## Current State
- Source files: N
- Test files: N
- Coverage ratio: N%

## Priority Matrix
| Module | Risk | Current Coverage | Recommended Tests | Priority |
|--------|------|-----------------|-------------------|----------|

## Testing Approach
### Unit Tests
### Integration Tests
### E2E Tests

## Recommended Order
1. <highest priority module>
2. <next>

## Test Infrastructure Needs
- Fixtures needed
- Mocks needed
- CI integration

Rules

1. Analysis, not implementation: this skill produces a strategy document. It does not write tests (use add-tests for that).
2. Risk-based prioritization: not all code needs the same level of testing. Focus on high-risk, high-impact areas.
3. Be pragmatic: 80% coverage of critical paths beats 100% coverage of trivial code.
4. Respect existing patterns: recommend test types and tools that align with the project's existing test infrastructure.
5. No built-in explore agent: do NOT use the built-in explore subagent type.