diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/test/layout/cluster-test.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/test/layout/cluster-test.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,39 @@
+require("../env");
+require("../../d3");
+require("../../d3.layout");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.layout.cluster");
+
+suite.addBatch({
+  "cluster": {
+    topic: d3.layout.cluster,
+    "can handle an empty children array": function(cluster) {
+      assert.deepEqual(cluster.nodes({value: 1, children: [{value: 1, children: []}, {value: 1}]}).map(layout), [
+        {value: 1, depth: 0, x: 0.5,  y: 0},
+        {value: 1, depth: 1, x: 0.25, y: 1},
+        {value: 1, depth: 1, x: 0.75, y: 1}
+      ]);
+    },
+    "can handle zero-valued nodes": function(cluster) {
+      assert.deepEqual(cluster.nodes({value: 0, children: [{value: 0}, {value: 1}]}).map(layout), [
+        {value: 0, depth: 0, x: 0.5,  y: 0},
+        {value: 0, depth: 1, x: 0.25, y: 1},
+        {value: 1, depth: 1, x: 0.75, y: 1}
+      ]);
+    }
+  }
+});
+
+function layout(node) {
+  return {
+    value: node.value,
+    depth: node.depth,
+    x: node.x,
+    y: node.y
+  };
+}
+
+suite.export(module);