Add test for entries.

test/core/entries-test.js

@@ -0,0 +1,43 @@
+require("../env");
+require("../../d3");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.entries");
+
+suite.addBatch({
+  "entries": {
+    topic: function() {
+      return d3.entries;
+    },
+    "enumerates every entry": function(entries) {
+      assert.deepEqual(entries({a: 1, b: 2}), [
+        {key: "a", value: 1},
+        {key: "b", value: 2}
+      ]);
+    },
+    "includes entries defined on prototypes": function(entries) {
+      function abc() {
+        this.a = 1;
+        this.b = 2;
+      }
+      abc.prototype.c = 3;
+      assert.deepEqual(entries(new abc()), [
+        {key: "a", value: 1},
+        {key: "b", value: 2},
+        {key: "c", value: 3}
+      ]);
+    },
+    "includes null or undefined values": function(entries) {
+      var v = entries({a: undefined, b: null, c: NaN});
+      assert.equal(v.length, 3);
+      assert.deepEqual(v[0], {key: "a", value: undefined});
+      assert.deepEqual(v[1], {key: "b", value: null});
+      assert.equal(v[2].key, "c");
+      assert.isNaN(v[2].value);
+    }
+  }
+});
+
+suite.export(module);