Merge branch 'insert-function' into 3.1.0

d3.js

@@ -1695,11 +1695,12 @@ d3 = function() {
   };
   d3_selectionPrototype.insert = function(name, before) {
     name = d3.ns.qualify(name);
-    function insert() {
-      return this.insertBefore(d3_document.createElementNS(this.namespaceURI, name), d3_select(before, this));
+    if (typeof before !== "function") before = d3_selection_selector(before);
+    function insert(d, i) {
+      return this.insertBefore(d3_document.createElementNS(this.namespaceURI, name), before.call(this, d, i));
     }
-    function insertNS() {
-      return this.insertBefore(d3_document.createElementNS(name.space, name.local), d3_select(before, this));
+    function insertNS(d, i) {
+      return this.insertBefore(d3_document.createElementNS(name.space, name.local), before.call(this, d, i));
     }
     return this.select(name.local ? insertNS : insert);
   };

src/core/selection-insert.js

@@ -1,19 +1,18 @@
-// TODO insert(node, function)?
-// TODO insert(function, string)?
-// TODO insert(function, function)?
 d3_selectionPrototype.insert = function(name, before) {
   name = d3.ns.qualify(name);
 
-  function insert() {
+  if (typeof before !== "function") before = d3_selection_selector(before);
+
+  function insert(d, i) {
     return this.insertBefore(
         d3_document.createElementNS(this.namespaceURI, name),
-        d3_select(before, this));
+        before.call(this, d, i));
   }
 
-  function insertNS() {
+  function insertNS(d, i) {
     return this.insertBefore(
         d3_document.createElementNS(name.space, name.local),
-        d3_select(before, this));
+        before.call(this, d, i));
   }
 
   return this.select(name.local ? insertNS : insert);

test/core/selection-insert-test.js

@@ -18,6 +18,14 @@ suite.addBatch({
       assert.domEqual(div[0][0], document.body.firstChild);
       assert.domEqual(div[0][0].nextSibling, span[0][0]);
     },
+    "inserts before the specified node": function(body) {
+      var span = body.html("").append("span");
+      var div = body.insert("div", function() { return span.node(); });
+      assert.equal(div[0][0].tagName, "DIV");
+      assert.isNull(div[0][0].namespaceURI);
+      assert.domEqual(div[0][0], document.body.firstChild);
+      assert.domEqual(div[0][0].nextSibling, span[0][0]);
+    },
     "appends an HTML element": function(body) {
       var div = body.insert("div");
       assert.equal(div[0][0].tagName, "DIV");