nyc
Metrics as of , from the GitHub or GitLab API of each repository. Refreshed monthly.
What nyc is
nyc is the command-line client for Istanbul, which measures JavaScript test coverage. Istanbul instruments ES5 and ES2015+ code with line counters to track how thoroughly unit tests exercise a codebase. nyc supports applications that spawn subprocesses. It produces source-mapped coverage for Babel and TypeScript projects. It wraps test runners such as tap, mocha and AVA, usually through an npm script. Options live in package.json, .nycrc files in JSON or YAML, or nyc.config.js. Reporters include lcov, HTML and text summaries. Coverage thresholds fail a run when branch, line, function or statement coverage drops below set values. The nyc merge command combines results from several test runs into one raw coverage file.
Written from the project's README, read .
- Category
- CI and reporting
- License
- ISC
- Language
- JavaScript
- Changelog
- Releases on GitHub
Repository metrics
Status
slowLast commit 91 to 365 days before the fetch date.Computed from the last commit date and the archive flag on the fetch date. See the status rules.
Alternatives
Listed CI and reporting tools, same primary language first, then by GitHub stars. Each line gives one fact from the tool's documentation where it differs from nyc's, with its source.
Lighthouse CI: Languages or inputs covered: URLs, or HTML files in a static build directory (staticDistDir). source: Docs: Configuration
c8: Languages or inputs covered: JavaScript run in Node.js through native V8 coverage; TypeScript and JSX through source maps. source: README
Allure Report: Languages or inputs covered: Result files written by framework integrations to the allure-results directory. source: Docs: How to generate a report
JaCoCo: Languages or inputs covered: Java code. source: README
Coverage.py: Languages or inputs covered: Python code (CPython 3.10 to 3.15, PyPy3). source: README
gotestsum: Languages or inputs covered: Go test output (go test -json). source: README
ReportPortal: Languages or inputs covered: Test results sent by framework agents; imported JUnit or Robot Framework XML files. source: Docs: Import data to ReportPortal
Test Reporter: Languages or inputs covered: Test result files in XML or JSON format. source: README
Comparisons
How to install
npm i -D nycQuestions
Is nyc open source?
Yes. nyc is released under ISC, an OSI-approved license, as reported by the GitHub API on 2026-09-22.
Is nyc maintained?
On 2026-09-22, the last commit to the default branch was on 2026-05-17, so the listed status is slow. Rule: Last commit 91 to 365 days before the fetch date.
How many GitHub stars does nyc have?
5,759 stars on 2026-09-22, from the GitHub API. The number is refreshed at each monthly update.
What language is nyc written in?
The repository's primary language, as reported by the GitHub API, is JavaScript.
How do I install nyc?
The README gives this command: npm i -D nyc
Sources
- GitHub REST API: repository, read
- GitHub REST API: commits, read
- GitHub REST API: latest release, read
- GitHub REST API: contributors, read
- README, read