I helped write a tool to perform software complexity analysis on JavaScript projects:
complexity-report
It reports a bunch of different complexity metrics: lines of code, number of parameters, cyclomatic complexity, cyclomatic density, Halstead complexity measures, the maintainability index, first-order density, change cost and core size.
It is released under the MIT license and built using Node.js and the Esprima JavaScript parser. It can be installed via npm, like so:
npm i -g complexity-report
