How do I load a node module as if the current module were located somewhere else?

I have some nodejs code running in a module somewhere. From this module, I would like to load a module located in a completely different place in the file system -- for example, given the path "/another/dir" and the module name "foo", I would like Node to act as if a module running in /another/dir had called require("foo"), rather than my own module.

  My code is running here
/some/folder/node_modules/mine/my_module.js

  I have the path "/another/dir/", the string "foo",
    and want to load this module
/another/dir/node_modules/foo/index.js

In other words, the module documentation refers to the process "require(X) from module at path Y", and I would like to specify my own value for Y

Can this be accomplished? If so, how? If not, why not?

Solution

The simplest, is just to resolve the path into an absolute path, this will be the recommended approach for most if not all cases.

var path = require('path');

var basedir = '/another/dir';
var filename = 'foo'; // renamed from dirname

var filepath = path.join(basedir, 'node_modules', filename);
var imports = require(filepath);

If you really need to make require act as if it is in a different directory, you can push the base directory to module.paths

module.paths.unshift('/another/dir/node_modules');

var imports = require('foo');

module.paths.shift();

module.paths can also be modified externally via the environment variable NODE_PATH, tho that would be the least recommended approach but this does apply it globally across all modules.