diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/test/core/functor-test.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/test/core/functor-test.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,29 @@
+require("../env");
+require("../../d3");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.functor");
+
+suite.addBatch({
+  "functor": {
+    topic: function() {
+      return d3.functor;
+    },
+    "when passed a function, returns the function": function(functor) {
+      function foo() {}
+      assert.strictEqual(functor(foo), foo);
+    },
+    "when passed a non-function, returns a wrapper function": function(functor) {
+      var a = {};
+      assert.isNull(functor(null)());
+      assert.isUndefined(functor(undefined)());
+      assert.strictEqual(functor(a)(), a);
+      assert.strictEqual(functor(1)(), 1);
+      assert.deepEqual(functor([1])(), [1]);
+    }
+  }
+});
+
+suite.export(module);