diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/test/env-assert.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/test/env-assert.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,96 @@
+var assert = require("assert");
+
+assert.inDelta = function(actual, expected, delta, message) {
+  if (!inDelta(actual, expected, delta)) {
+    assert.fail(actual, expected, message || "expected {actual} to be in within *" + delta + "* of {expected}", null, assert.inDelta);
+  }
+};
+
+assert.domNull = function(actual, message) {
+  if (actual !== null) {
+    assert.fail(actual+"", null, message || "expected null, got {actual}", "===", assert.domNull);
+  }
+};
+
+assert.domEqual = function(actual, expected, message) {
+  if (actual !== expected) {
+    assert.fail(actual+"", expected+"", message || "expected {expected}, got {actual}", "===", assert.domEqual);
+  }
+};
+
+assert.rgbEqual = function(actual, r, g, b, message) {
+  if (actual.r !== r || actual.g !== g || actual.b !== b) {
+    assert.fail("rgb(" + actual.r + "," + actual.g + "," + actual.b + ")", "rgb(" + r + ", " + g + ", " + b + ")", message || "expected {expected}, got {actual}", "===", assert.rgbEqual);
+  }
+};
+
+assert.hslEqual = function(actual, h, s, l, message) {
+  if (Math.abs(actual.h - h) > 1e-6 || Math.abs(actual.s - s) > 1e-6 || Math.abs(actual.l - l) > 1e-6) {
+    assert.fail("hsl(" + actual.h + "," + (actual.s * 100) + "%," + (actual.l * 100) + "%)", "hsl(" + h + "," + (s * 100) + "%," + (l * 100) + "%)", message || "expected {expected}, got {actual}", null, assert.hslEqual);
+  }
+};
+
+assert.pathEqual = function(actual, expected, message) {
+  if (!pathEqual(actual, expected)) {
+    assert.fail(formatPath(actual), formatPath(expected), message || "expected {expected}, got {actual}", null, assert.pathEqual);
+  }
+};
+
+function inDelta(actual, expected, delta) {
+  return (Array.isArray(expected) ? inDeltaArray : inDeltaNumber)(actual, expected, delta);
+}
+
+function inDeltaArray(actual, expected, delta) {
+  var n = expected.length, i = -1;
+  if (actual.length !== n) return false;
+  while (++i < n) if (!inDelta(actual[i], expected[i], delta)) return false;
+  return true;
+}
+
+function inDeltaNumber(actual, expected, delta) {
+  return actual >= expected - delta && actual <= expected + delta;
+}
+
+function pathEqual(a, b) {
+  a = parsePath(a);
+  b = parsePath(b);
+  var n = a.length, i = -1, x, y;
+  if (n !== b.length) return false;
+  while (++i < n) {
+    x = a[i];
+    y = b[i];
+    if (typeof x === "string") {
+      if (x !== y) return false;
+    } else if (typeof y !== "number") {
+      return false;
+    } else if (Math.abs(x - y) > 1e-6) {
+      return false;
+    }
+  }
+  return true;
+}
+
+var reNumber = /[-+]?(?:\d+\.\d+|\d+\.|\.\d+|\d+)(?:[eE][-]?\d+)?/g;
+
+function parsePath(path) {
+  var parts = [];
+  reNumber.lastIndex = 0;
+  for (var i = 0, s0 = 0, s1, m; m = reNumber.exec(path); ++i) {
+    if (m.index) {
+      var part = path.substring(s0, s1 = m.index);
+      if (!/^[, ]$/.test(part)) parts.push(part);
+    }
+    parts.push(parseFloat(m[0]));
+    s0 = reNumber.lastIndex;
+  }
+  if (s0 < path.length) parts.push(path.substring(s0));
+  return parts;
+}
+
+function formatPath(path) {
+  return path.replace(reNumber, formatNumber);
+}
+
+function formatNumber(s) {
+  return Math.abs((s = +s) - Math.floor(s)) < 1e-6 ? Math.floor(s) : s.toFixed(6);
+}