Add test for tree layout.

For now, test the bug we just fixed.
flyingoctopus · Aug 19, 2011 · 3c0f299 · 3c0f299
1 parent 43aeb60
commit 3c0f299
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Showing 4 changed files with 26 additions and 5 deletions.
diff --git a/d3.layout.js b/d3.layout.js
@@ -1484,8 +1484,8 @@ d3.layout.tree = function() {
     function firstWalk(node, previousSibling) {
       var children = node.children,
           layout = node._tree;
-      if (children && children.length) {
-        var n = children.length,
+      if (children && (n = children.length)) {
+        var n,
             firstChild = children[0],
             previousChild,
             ancestor = firstChild,

diff --git a/d3.layout.min.js b/d3.layout.min.js
diff --git a/src/layout/tree.js b/src/layout/tree.js
@@ -11,8 +11,8 @@ d3.layout.tree = function() {
     function firstWalk(node, previousSibling) {
       var children = node.children,
           layout = node._tree;
-      if (children && children.length) {
-        var n = children.length,
+      if (children && (n = children.length)) {
+        var n,
             firstChild = children[0],
             previousChild,
             ancestor = firstChild,

diff --git a/test/layout/tree-test.js b/test/layout/tree-test.js
@@ -0,0 +1,21 @@
+require("../env");
+require("../../d3");
+require("../../d3.layout");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.layout.tree");
+
+suite.addBatch({
+  "tree": {
+    topic: d3.layout.tree,
+    "can handle an empty children array": function(tree) {
+      assert.deepEqual(tree.nodes({children: []}), [
+        {children: [], depth: 0, x: 0.5, y: 0}
+      ]);
+    }
+  }
+});
+
+suite.export(module);