Test Coverage Skill

Understand and use the test coverage registry system.

Overview

The registries are files that document what exists in the system and its test coverage state.

When to Use This Skill

• Evaluating current test coverage
• Identifying coverage gaps
• Planning testing priorities
• Generating coverage reports
• Understanding test distribution

Registry Structures

FEATURE_REGISTRY

Lists all system features with coverage state:

FEATURE_REGISTRY = {
  'checkout': {
    name: 'Checkout',
    description: 'Purchase process',
    entities: ['orders', 'payments'],
    tests: ['checkout.cy.ts'],
    coverage: 'full'  // full | partial | none
  },
  'inventory': {
    name: 'Inventory Management',
    description: 'Stock management',
    entities: ['inventory', 'warehouses'],
    tests: [],
    coverage: 'none'
  }
}

FLOW_REGISTRY

Lists user flows with coverage state:

FLOW_REGISTRY = {
  'login': {
    name: 'User Login',
    steps: ['Visit login', 'Enter credentials', 'Submit', 'Redirect'],
    entities: ['users', 'sessions'],
    tests: ['auth/login.cy.ts'],
    coverage: 'full'
  },
  'returns': {
    name: 'Process Returns',
    steps: ['Find order', 'Request return', 'Approve', 'Refund'],
    entities: ['orders', 'returns', 'payments'],
    tests: [],
    coverage: 'none'
  }
}

A flow without coverage means no automated tests verify that user path end-to-end.

TAGS_REGISTRY

Lists all test tags with distribution:

TAGS_REGISTRY = {
  '@smoke': { count: 15, files: ['login.cy.ts', 'products.cy.ts'] },
  '@uat': { count: 52, files: [...] },
  '@api': { count: 75, files: [...] },
  '@entity-products': { count: 20, files: ['products.cy.ts'] }
}

COVERAGE_SUMMARY

Aggregated coverage metrics:

COVERAGE_SUMMARY = {
  features: {
    total: 25,
    covered: 20,
    partial: 3,
    none: 2,
    percentage: 80
  },
  flows: {
    total: 15,
    covered: 10,
    percentage: 67
  },
  entities: {
    total: 12,
    withApiTests: 12,
    withUatTests: 10,
    percentage: 100
  }
}

Technical vs Functional Coverage

Critical Distinction

Why This Matters

Feature: Products
Tests: 10
Technical coverage: 100% ✓

But...
- Do tests verify validations?
- Do tests cover edge cases?
- Do tests check permissions?

Functional coverage: ??? (requires manual analysis)

IMPORTANT: Registry coverage metrics are TECHNICAL. They don't indicate test quality.

Using Coverage Metrics

To Identify Gaps

1. Find features with coverage: 'none'
2. Find flows without tests
3. Find entities with gaps

To Prioritize

Metrics help identify areas without tests, but prioritization must consider:

For Reporting

## Coverage Status - Sprint 15

- Features covered: 80% (20/25)
- Flows covered: 67% (10/15)
- Critical gaps identified:
  - Feature: inventory (no tests)
  - Flow: returns (no tests)

File Locations

DevTools Pages

• Features: /devtools/features
• Flows: /devtools/flows
• Tags: /devtools/tags

Registry Files

• apps/dev/.nextspark/registries/testing-registry.ts

Commands

Common Questions

Does 100% coverage mean we're good?

Not necessarily. 100% technical coverage means tests exist, not that they're good or complete.

Does 0% coverage mean it's bad?

Not necessarily. Some areas may not need automated tests, or may be covered by manual testing.

How do I improve coverage?

1. Identify gaps with /coverage:gaps
2. Prioritize by business criticality
3. Create tests for most critical areas
4. Verify tests check the right things

Important Notes

1. Technical ≠ Functional - Having tests doesn't mean they test the right things
2. Metrics guide, don't decide - Use business context to prioritize
3. Quality over quantity - 10 good tests beat 100 bad ones
4. Living documentation - Registries should stay updated

YOU decide how to interpret these metrics and what to prioritize based on business context.