Question

Other than grabbing the package.json file at the project root is there a way to determine the list of dependencies of a running node.js application? Does node keep this meta information available as some var in the global namespace?

Answer 1

If you are just looking for the currently installed npm packages in the application directory, then you can install the npm package (npm install -g npm) and programatically invoke ls to list the installed packages and the dependency trees.

Obviously, this has no bearing on whether the installed packages are actually require‘d in the application or not.

Usage is not that well documented but this should get you started.

var npm = require('npm');

npm.load(function(err, npm) {
    npm.commands.ls([], true, function(err, data, lite) {
        console.log(data); //or lite for simplified output
    });
});

e.g.:

{ dependencies:
   { npm: { version: '1.1.18', dependencies: [Object] },
     request: { version: '2.9.202' } } }

Otherwise, I believe the only other option is to introspect the module module to get information pertaining to the currently loaded/cached module paths. However this definitely does not look to have been developed as a public API. I’m not sure if there are any alternatives so would be keen to hear if there are e.g.

var req = require('request'); // require some module for demo purposes
var m = require('module');

// properties of m contain current loaded module info, e.g. m._cache