diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/test/core/xhr-test.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/test/core/xhr-test.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,56 @@
+require("../env");
+require("../../d3");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.xhr");
+
+suite.addBatch({
+  "xhr": {
+    topic: function() {
+      var cb = this.callback;
+      return d3.xhr("examples/data/sample.txt", function(req) {
+        cb(null, req);
+      });
+    },
+    "makes an asynchronous HTTP request": function(req) {
+      assert.equal(req._info.url, "examples/data/sample.txt");
+      assert.isTrue(req._info.async);
+    },
+    "invokes the callback with the request object": function(req) {
+      assert.equal(req.responseText, "Hello, world!\n");
+    },
+    "does not override the mime type by default": function(req) {
+      assert.isUndefined(req._info.mimeType);
+    },
+    "waits until the request is done": function(req) {
+      assert.equal(req.readyState, 4);
+      assert.equal(req.status, 200);
+    },
+    "": {
+      topic: function() {
+        var cb = this.callback;
+        return d3.xhr("examples/data/sample.txt", "text/plain", function(req) {
+          cb(null, req);
+        });
+      },
+      "observes the optional mime type": function(req) {
+        assert.equal(req._info.mimeType, "text/plain");
+      }
+    },
+    " ": {
+      topic: function() {
+        var cb = this.callback;
+        return d3.xhr("//does/not/exist.txt", function(req) {
+          cb(null, req);
+        });
+      },
+      "invokes the callback with null when an error occurs": function(req) {
+        assert.isNull(req);
+      }
+    }
+  }
+});
+
+suite.export(module);