How AI describes nyc

nyc is Istanbul's command-line tool that instruments ES5 and ES2015+ JavaScript code with line counters to measure how well unit tests exercise your code. It works with most JavaScript test runners (such as mocha, AVA, and tap) and can be installed as a dev dependency or run via npx, though Jest or Tap already include IstanbulJS coverage, so nyc may not be needed in those cases. It generates coverage reports (lcov and text-summary) and supports configuration via command-line options or config files (e.g., .nycrc, nyc.config.js, package.json), with presets for Babel and TypeScript projects.