I require a module that was installed via npm. I want to access a .js file subordinate to that module (so I can subclass a Constructor method in it). I can't (well, don't want to) modify the module's code, so don't have a place to extract its __dirname.
I am aware of the following question, but it is about getting the path of a module that one has code control over (hence, __dirname is the solution):
In Node.js how can I tell the path of `this` module?
Even better would be to get the module's loaded module info
If I correctly understand your question, you should use require.resolve():
Use the internal require() machinery to look up the location of a module, but rather than loading the module, just return the resolved filename.
var pathToModule = require.resolve('module');