c8

c8 measures code coverage using the coverage functionality built into Node.js and the V8 JavaScript engine, rather than instrumenting the source code. Its output is compatible with Istanbul’s reporters.

Like nyc, c8 wraps the command that runs the tests or the program, for example c8 node foo.js, and outputs coverage metrics for the executed files. Because no instrumentation step is needed, transpiled code and ES modules are handled without extra configuration, using source maps where available. c8 is configured with command-line flags, a c8 section in package.json or a JSON configuration file, and can enforce coverage thresholds.

c8 is free and open source under the ISC licence.