diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/test/core/sum-test.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/test/core/sum-test.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,47 @@
+require("../env");
+require("../../d3");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.sum");
+
+suite.addBatch({
+  "sum": {
+    topic: function() {
+      return d3.sum;
+    },
+    "sums numbers": function(sum) {
+      assert.equal(d3.sum([1]), 1);
+      assert.equal(d3.sum([5, 1, 2, 3, 4]), 15);
+      assert.equal(d3.sum([20, 3]), 23);
+      assert.equal(d3.sum([3, 20]), 23);
+    },
+    "sums types that can be coerced to numbers": function(sum) {
+      assert.equal(d3.sum(["20", "3"]), 23);
+      assert.equal(d3.sum(["3", "20"]), 23);
+      assert.equal(d3.sum(["3", 20]), 23);
+      assert.equal(d3.sum([20, "3"]), 23);
+      assert.equal(d3.sum([3, "20"]), 23);
+      assert.equal(d3.sum(["20", 3]), 23);
+    },
+    "ignores non-numeric types": function(sum) {
+      assert.equal(d3.sum(["a", "b", "c"]), 0);
+      assert.equal(d3.sum(["a", 1, "2"]), 3);
+    },
+    "ignores null, undefined and NaN": function(sum) {
+      assert.equal(d3.sum([NaN, 1, 2, 3, 4, 5]), 15);
+      assert.equal(d3.sum([1, 2, 3, 4, 5, NaN]), 15);
+      assert.equal(d3.sum([10, null, 3, undefined, 5, NaN]), 18);
+    },
+    "applies the optional acccessor function": function(sum) {
+      assert.equal(d3.sum([[1, 2, 3, 4, 5], [2, 4, 6, 8, 10]], function(d) { return d3.sum(d); }), 45);
+      assert.equal(d3.sum([1, 2, 3, 4, 5], function(d, i) { return i; }), 10);
+    },
+    "returns zero for the empty array": function(sum) {
+      assert.equal(d3.sum([]), 0);
+    }
+  }
+});
+
+suite.export(module);