nodejs automatic url to folder mapping - node.js

Question

I'm new to nodejs. What I want is to have several apps run at different context roots based on the directory structure. (all must be online at the same time)
For Example:
dir1
|____test1.js
|____test2.js
dir2
|____test1.js
|____test2.js
http://localhost:3000/dir1/test1
http://localhost:3000/dir1/test2
http://localhost:3000/dir2/test1
http://localhost:3000/dir2/test2
It's desired to automatically discover the scripts and create the end points.
I could not find such a feature in a test framework like mocha.
Can you please guide me with nodejs server url mapping?
Update:
I've tried this:
var express = require('express');
var app = express();
entrypoints = ["/a", "/b", "/c"]
entrypoints.forEach(function(val, index, arr){
app.get(val, function(req, res){
x = require("."+val+".js");
x.handle(req, res);
});
}
app.listen(3000);
where each a.js, b.js, c.js implements the handle but it fails; it does not like putting app.get inside a loop:
app.listen(3000);
^^^
SyntaxError: Unexpected identifier
at Module._compile (module.js:439:25)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Function.Module.runMain (module.js:497:10)
at startup (node.js:119:16)
at node.js:906:3