diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/test/geom/polygon-test.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/test/geom/polygon-test.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,57 @@
+require("../env");
+require("../../d3");
+require("../../d3.geom");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.geom.polygon");
+
+suite.addBatch({
+  "counterclockwise polygon (last point equal to start point)": {
+    topic: function() {
+      return d3.geom.polygon([[0, 0], [0, 1], [1, 1], [1, 0], [0, 0]]);
+    },
+    "area": function(polygon) {
+      assert.equal(polygon.area(), 1);
+    },
+    "centroid": function(polygon) {
+      assert.deepEqual(polygon.centroid(), [.5, .5]);
+    }
+  },
+  "counterclockwise polygon (implicitly ending at start point)": {
+    topic: function() {
+      return d3.geom.polygon([[0, 0], [0, 1], [1, 1], [1, 0]]);
+    },
+    "area": function(polygon) {
+      assert.equal(polygon.area(), 1);
+    },
+    "centroid": function(polygon) {
+      assert.deepEqual(polygon.centroid(), [.5, .5]);
+    }
+  },
+  "clockwise polygon (last point equal to start point)": {
+    topic: function() {
+      return d3.geom.polygon([[0, 0], [1, 0], [1, 1], [0, 1], [0, 0]]);
+    },
+    "area": function(polygon) {
+      assert.equal(polygon.area(), -1);
+    },
+    "centroid": function(polygon) {
+      assert.deepEqual(polygon.centroid(), [.5, .5]);
+    }
+  },
+  "clockwise polygon (implicitly ending at start point)": {
+    topic: function() {
+      return d3.geom.polygon([[0, 0], [1, 0], [1, 1], [0, 1]]);
+    },
+    "area": function(polygon) {
+      assert.equal(polygon.area(), -1);
+    },
+    "centroid": function(polygon) {
+      assert.deepEqual(polygon.centroid(), [.5, .5]);
+    }
+  }
+});
+
+suite.export(module);