Testing Strategy Skill

Build production-grade test suites with clear purpose at every layer. Assess what exists, recommend what's missing, implement with precision.

Workflow

1. Audit — scan codebase for existing tests, coverage, gaps
2. Recommend — propose test strategy (which types, priorities, ratios)
3. Implement — write tests following the patterns below

Testing Pyramid

Each layer has a job. Don't test the same thing twice at different layers.

Unit Tests

Pure functions, calculations, transformations. No I/O, no state. Fast.

• Domain rules, validators, formatters, parsers
• Edge cases: empty input, boundary values, overflow, unicode
• One assertion per logical concept