nyc
the Istanbul command line interface observed · 2026-10-17
Health v2 · maintenance only
64/100
- Activity 74
- Release rhythm 32
- Longevity 100
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-10-21. Adoption (stars, forks) is never an input.
- gap_med: n/a
- age_days: 4183
- days_rel: 240
- days_push: 156
- n_releases_24m: 1
Adoption not part of the score
5759 stars · 362 forks observed · 2026-10-17
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded
nyc is the official command-line interface for Istanbul, a JavaScript code coverage tool that instruments ES5 and ES2015+ code with line counters. It wraps test runners like mocha, AVA, and tap to collect and report coverage, including source-mapped coverage for Babel and TypeScript projects.
Use cases
- measure code coverage of my mocha tests
- generate lcov and html coverage reports for a JavaScript project
- get coverage for TypeScript or Babel code
- instrument subprocesses spawned during tests
- track how well unit tests exercise the codebase
When to choose
- you need coverage for a Node.js project using mocha, AVA, or a runner without built-in coverage
- you need source-mapped coverage for Babel or TypeScript
- you need to instrument subprocesses spawned by your tests
When to avoid
- you use Jest or node-tap, which already bundle Istanbul coverage
- you prefer V8-native coverage via c8 without instrumentation
Facets
cli-tool · maturity stable
testing cli developer-tools testing developer-tools cli cross-platform code-coverage istanbul javascript instrumentation test-coverage mocha source-maps nodejs
5 sources
- readme: https://github.com/istanbuljs/nyc · fetched 2026-10-17 · 2d7e255ac0bc
- homepage: https://istanbul.js.org/ · fetched 2026-08-29 · fd7d4665a956
- site_page: https://istanbul.js.org/docs/tutorials · fetched 2026-08-29 · e230905c262a
- site_page: https://istanbul.js.org/docs/advanced · fetched 2026-08-29 · 95604956c652
- site_page: https://istanbul.js.org/integrations · fetched 2026-08-29 · 814122882865
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| istanbuljs/nyc | main | 64 |
| istanbuljs/istanbuljs | infra | 53 |
| istanbuljs/babel-plugin-istanbul | plugin | 73 |
| istanbuljs/puppeteer-to-istanbul | plugin | 23 |
For agents
Data as of 2026-10-19T08:05:51.212177+00:00 · Report a problem