diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/test/scale/category-test.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/test/scale/category-test.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,74 @@
+require("../env");
+require("../../d3");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.scale.category");
+
+suite.addBatch({
+  "category10": category(d3.scale.category10, 10),
+  "category20": category(d3.scale.category20, 20),
+  "category20b": category(d3.scale.category20b, 20),
+  "category20c": category(d3.scale.category20c, 20)
+});
+
+function category(category, n) {
+  return {
+    "is an ordinal scale": function() {
+      var x = category(), colors = x.range();
+      assert.length(x.domain(), 0);
+      assert.length(x.range(), n);
+      assert.equal(x(1), colors[0]);
+      assert.equal(x(2), colors[1]);
+      assert.equal(x(1), colors[0]);
+      var y = x.copy();
+      assert.deepEqual(y.domain(), x.domain());
+      assert.deepEqual(y.range(), x.range());
+      x.domain(d3.range(n));
+      for (var i = 0; i < n; ++i) assert.equal(x(i + n), x(i));
+      assert.equal(y(1), colors[0]);
+      assert.equal(y(2), colors[1]);
+    },
+    "each instance is isolated": function() {
+      var a = category(), b = category(), colors = a.range();
+      assert.equal(a(1), colors[0]);
+      assert.equal(b(2), colors[0]);
+      assert.equal(b(1), colors[1]);
+      assert.equal(a(1), colors[0]);
+    },
+    "contains the expected number of values in the range": function() {
+      var x = category();
+      assert.length(x.range(), n);
+    },
+    "each range value is distinct": function() {
+      var map = {}, count = 0, x = category();
+      x.range().forEach(function(v) {
+        if (!(v in map)) {
+          map[v] = ++count;
+        }
+      });
+      assert.equal(count, x.range().length);
+    },
+    "each range value is a hexadecimal color": function() {
+      var x = category();
+      x.range().forEach(function(v) {
+        assert.match(v, /#[0-9a-f]{6}/);
+        v = d3.rgb(v);
+        assert.isFalse(isNaN(v.r));
+        assert.isFalse(isNaN(v.g));
+        assert.isFalse(isNaN(v.b));
+      });
+    },
+    "no range values are very dark or very light": function() {
+      var x = category();
+      x.range().forEach(function(v) {
+        var c = d3.hsl(v);
+        assert.isTrue(c.l >= .34, "expected " + v + " to be lighter (l = " + c.l + ")");
+        assert.isTrue(c.l <= .89, "expected " + v + " to be darker (l = " + c.l + ")");
+      });
+    }
+  };
+}
+
+suite.export(module);