It's a container now.

lib/index.js

@@ -65,14 +65,21 @@ function Config(parent, defaultEnvVar, customizer) {
     return this;
   };
 
-  config.get = function (setting) {
+  config.getRaw = function (setting) {
     if (!settings.hasOwnProperty(setting)) {
       if (parent) {
-        return parent.get(setting);
+        return parent.getRaw(setting);
       }
       return undefined;
     }
-    return settings[setting]();
+    return settings[setting];
+  };
+
+  config.get = function (setting) {
+    var args = Array.prototype.slice.apply(arguments);
+    var getter = this.getRaw(setting);
+    if (!getter) { return undefined; }
+    return getter.apply(this, args);
   };
 
   config.has = function (setting) {

test/config-test.js

@@ -393,6 +393,30 @@ describe('Setting getters', function () {
     var spy = sinon.spy(getter);
     c.set('setting', spy);
     c.get('setting').should.equal(spy);
-    spy.callCount.should.equal(0);    
+    spy.callCount.should.equal(0);
+  });
+
+  it('should be invoked with parameters that are passed on get call', function () {
+    var spy = sinon.spy(function () { return 'a value'; });
+    c.setFunc('setting', spy);
+
+    c.get('setting', 1, 3, 'hello').should.equal('a value');
+    spy.calledWithExactly('setting', 1, 3, 'hello').should.be.true;
+  });
+
+  it('should be invoked with config that get was called on as context', function () {
+    var c2 = c('child');
+
+    var spy = sinon.spy(function (s, n1) { return 'a value for ' + s + ' is ' + n1; });
+    c.setFunc('setting', spy);
+
+    c2.get('setting', 37, 42).should.equal('a value for setting is 37');
+    spy.alwaysCalledOn(c2).should.be.true;
+  });
+
+  it('should be able to request other values from config', function () {
+    c.setFunc('root', function () { return 'root: ' + this.get('child'); });
+    c.set('child', 'child value');
+    c.get('root').should.equal('root: child value');
   });
 });