Husky Test Coverage
Set up or verify Husky git hooks to ensure tests run and coverage thresholds are enforced on every commit.
Purpose
This skill automates the setup of:
Husky git hooks for pre-commit testing Test runner detection (Jest, Vitest, Mocha) Coverage configuration with thresholds (default: 80%) Pre-commit hook that runs tests with coverage Configurable coverage enforcement (block or warn) When to Use
This skill should be used when:
Setting up test coverage enforcement for the first time Verifying existing Husky/test setup is correctly configured Ensuring coverage thresholds are met before commits Configuring pre-commit hooks for test coverage Adapting coverage setup to different test runners Project Context Discovery
Before setting up test coverage, discover the project's context:
Check package.json:
Review existing test scripts Detect test runner from dependencies (jest, vitest, mocha) Check for existing Husky installation Review existing coverage configuration
Identify Test Runner:
Jest: Check for jest in dependencies, look for jest.config.js or jest.config.json Vitest: Check for vitest in dependencies, look for vitest.config.ts or vitest.config.js Mocha: Check for mocha in dependencies, check for coverage tool (nyc, c8)
Check Coverage Configuration:
Jest: Look for coverageThreshold in jest.config. Vitest: Look for coverage.thresholds in vitest.config. Mocha: Look for .nycrc.json or coverage config in package.json
Verify Existing Husky Setup:
Check if .husky/ directory exists Review existing pre-commit hook Check if Husky is in package.json dependencies
Detect Test Files:
Scan for .test. or .spec. files Verify tests exist before enforcing coverage Quick Start
Basic setup (80% coverage threshold, blocks commits below threshold)
python3 ~/.claude/skills/husky-test-coverage/scripts/setup-husky-coverage.py \ --root /path/to/project
Custom threshold (85%)
python3 ~/.claude/skills/husky-test-coverage/scripts/setup-husky-coverage.py \ --root /path/to/project \ --threshold 85
Warn only (don't block commits)
python3 ~/.claude/skills/husky-test-coverage/scripts/setup-husky-coverage.py \ --root /path/to/project \ --no-fail-on-below
Skip if no tests found
python3 ~/.claude/skills/husky-test-coverage/scripts/setup-husky-coverage.py \ --root /path/to/project \ --skip-if-no-tests
Dry run to preview changes
python3 ~/.claude/skills/husky-test-coverage/scripts/setup-husky-coverage.py \ --root /path/to/project \ --dry-run
What Gets Configured Husky Setup Installs Husky if not already present Initializes Husky (npx husky install) Creates .husky/pre-commit hook that runs tests with coverage Adds prepare script to package.json (if missing) Test Runner Detection
The skill automatically detects:
Jest: Uses jest --coverage --watchAll=false in pre-commit hook Vitest: Uses vitest --coverage --run in pre-commit hook Mocha: Uses nyc or c8 with mocha test command Coverage Configuration
Jest:
Creates or updates jest.config.json with coverageThreshold Default thresholds: 80% lines, 75% branches, 80% functions, 80% statements
Vitest:
Creates or updates vitest.config.ts/js with coverage thresholds Configures v8 coverage provider Sets same default thresholds as Jest
Mocha + nyc:
Creates or updates .nycrc.json with coverage thresholds Configures text, html, and lcov reporters Pre-commit Hook
The created hook:
Runs tests with coverage before every commit
Fails the commit if coverage is below threshold (configurable)
Can skip if no test files are found (optional)
Configuration Options
Command Line Arguments
--root
Create .husky-test-coverage.json in project root:
{ "coverageThreshold": { "lines": 80, "branches": 75, "functions": 80, "statements": 80 }, "failOnCoverageBelowThreshold": true, "skipIfNoTests": false }
Package.json Configuration
Alternatively, add to package.json:
{ "huskyTestCoverage": { "threshold": 80, "failOnBelow": true } }
Tech Stack Adaptation Jest Projects
Detection:
Checks for jest in dependencies Looks for jest.config.js or jest.config.json
Configuration:
Updates or creates jest.config.json with coverage thresholds Pre-commit hook: npm test -- --coverage --watchAll=false
Example jest.config.json:
{ "coverageThreshold": { "global": { "lines": 80, "branches": 75, "functions": 80, "statements": 80 } } }
Vitest Projects
Detection:
Checks for vitest in dependencies Looks for vitest.config.ts or vitest.config.js
Configuration:
Updates or creates Vitest config with coverage thresholds Pre-commit hook: npm test -- --coverage --run
Example vitest.config.ts:
import { defineConfig } from 'vitest/config'
export default defineConfig({ test: { coverage: { provider: 'v8', reporter: ['text', 'json', 'html'], thresholds: { lines: 80, branches: 75, functions: 80, statements: 80 } } } })
Mocha Projects
Detection:
Checks for mocha in dependencies Checks for coverage tool (nyc or c8)
Configuration:
Creates or updates .nycrc.json for nyc Pre-commit hook: nyc --reporter=text --reporter=html npm test
Example .nycrc.json:
{ "check-coverage": true, "lines": 80, "branches": 75, "functions": 80, "statements": 80, "reporter": ["text", "text-summary", "html", "lcov"] }
Package Manager Support
The skill automatically detects and uses:
npm: npm run test yarn: yarn test pnpm: pnpm run test bun: bun run test Workflow
When using this skill:
Discover Project Context:
Scan package.json for test runner and dependencies Check existing Husky configuration Review existing coverage config files Verify test files exist
Detect Test Runner:
Identify Jest, Vitest, or Mocha Detect coverage tool (built-in or nyc/c8) Determine package manager
Setup or Verify Husky:
Install Husky if missing Initialize Husky hooks Add prepare script if needed
Configure Coverage:
Create or update coverage configuration Set coverage thresholds (default 80%) Configure appropriate reporters
Create Pre-commit Hook:
Generate hook script with test command Configure to run tests with coverage Set enforcement behavior (block or warn)
Verify Setup:
Review generated configuration Test hook with a commit Adjust thresholds if needed Integration with Other Skills
This skill works alongside:
Skill How It Works Together fullstack-workspace-init Automatically invoked after scaffolding to set up 80% coverage threshold linter-formatter-init Both configure Husky; this skill focuses on test coverage, linter-formatter-init focuses on linting/formatting testing-expert Uses testing patterns and coverage targets from testing-expert skill Automatic Setup with fullstack-workspace-init
When using fullstack-workspace-init to scaffold a new project, this skill is automatically applied with:
Vitest as the test runner 80% coverage threshold Pre-commit hooks enabled GitHub Actions CI/CD integration
You don't need to run this skill separately if you used fullstack-workspace-init.
Manual Integration
If adding to an existing project:
python3 ~/.claude/skills/husky-test-coverage/scripts/setup-husky-coverage.py \ --root /path/to/project \ --threshold 80
Troubleshooting Pre-commit hook not running
Reinstall Husky
npx husky install chmod +x .husky/pre-commit
Coverage not being checked Verify test command includes coverage flag Check coverage configuration file exists and is correct Ensure coverage tool is installed (nyc/c8 for Mocha) Hook fails even when tests pass Check coverage thresholds are achievable Review coverage report to see what's below threshold Consider adjusting thresholds or improving test coverage Tests run but coverage not enforced Verify coverage configuration file has correct thresholds Check test runner supports coverage (Jest/Vitest have built-in, Mocha needs nyc/c8) Review pre-commit hook script for correct command Multiple test runners detected
The skill uses the first detected runner in priority order: Vitest > Jest > Mocha
Best Practices Start with reasonable thresholds: Begin with 80% and adjust based on project needs Monitor coverage trends: Use coverage reports to identify gaps Incremental improvement: Gradually increase thresholds as coverage improves Consider context: Some files (utilities, configs) may not need high coverage Use with CI/CD: Pre-commit hooks catch issues early, but CI/CD provides final gate Team alignment: Ensure team understands coverage requirements and goals Resources Husky Documentation: https://typicode.github.io/husky/ Jest Coverage: https://jestjs.io/docs/configuration#coveragethreshold-object Vitest Coverage: https://vitest.dev/config/#coverage nyc (Istanbul): https://github.com/istanbuljs/nyc
When this skill is active, Claude will:
Discover project test setup and configuration Detect test runner and coverage tool Set up or verify Husky installation Configure coverage thresholds appropriately Create pre-commit hook that enforces coverage Provide troubleshooting guidance when needed