diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/test/core/json-test.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/test/core/json-test.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,37 @@
+require("../env");
+require("../../d3");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.json");
+
+suite.addBatch({
+  "json": {
+    topic: function() {
+      var cb = this.callback;
+      return d3.json("examples/data/sample.json", function(json) {
+        cb(null, json);
+      });
+    },
+    "invokes the callback with the loaded JSON": function(json) {
+      assert.deepEqual(json, [{"Hello":42,"World":"\"fish\""}]);
+    },
+    "overrides the mime type to application/json": function(json) {
+      assert.equal(XMLHttpRequest._last._info.mimeType, "application/json");
+    },
+    "": {
+      topic: function() {
+        var cb = this.callback;
+        return d3.json("//does/not/exist.json", function(json) {
+          cb(null, json);
+        });
+      },
+      "invokes the callback with null when an error occurs": function(json) {
+        assert.isNull(json);
+      }
+    }
+  }
+});
+
+suite.export(module);