Store normalized vnodes in the dom element. Add render tests. (#2266)

* Store normalized vnodes in the dom element. Add render tests.

* Add entry to change-log

docs/change-log.md

@@ -60,6 +60,7 @@
 - render/hooks: fixed an ommission that caused `oninit` to be called unnecessarily in some cases [#1992](https://github.com/MithrilJS/mithril.js/issues/1992)
 - docs: tweaks: ([#2104](https://github.com/MithrilJS/mithril.js/pull/2104) [@mikeyb](https://github.com/mikeyb), [#2205](https://github.com/MithrilJS/mithril.js/pull/2205), [@cavemansspa](https://github.com/cavemansspa), [#2265](https://github.com/MithrilJS/mithril.js/pull/2265), [@isiahmeadows](https://github.com/isiahmeadows))
 - render/core: avoid touching `Object.prototype.__proto__` setter with `key: "__proto__"` in certain situations ([#2251](https://github.com/MithrilJS/mithril.js/pull/2251))
+- render/core: Vnodes stored in the dom node supplied to `m.render()` are now normalized [#2266](https://github.com/MithrilJS/mithril.js/pull/2266)
 
 ---
 

render/render.js

@@ -865,8 +865,8 @@ module.exports = function($window) {
 		// First time rendering into a node clears it out
 		if (dom.vnodes == null) dom.textContent = ""
 
-		if (!Array.isArray(vnodes)) vnodes = [vnodes]
-		updateNodes(dom, dom.vnodes, Vnode.normalizeChildren(vnodes), hooks, null, namespace === "http://www.w3.org/1999/xhtml" ? undefined : namespace)
+		vnodes = Vnode.normalizeChildren(Array.isArray(vnodes) ? vnodes : [vnodes])
+		updateNodes(dom, dom.vnodes, vnodes, hooks, null, namespace === "http://www.w3.org/1999/xhtml" ? undefined : namespace)
 		dom.vnodes = vnodes
 		// document.activeElement can return null in IE https://developer.mozilla.org/en-US/docs/Web/API/Document/activeElement
 		if (active != null && $doc.activeElement !== active && typeof active.focus === "function") active.focus()

render/tests/test-render.js

@@ -12,6 +12,32 @@ o.spec("render", function() {
 		render = vdom($window).render
 	})
 
+	o("renders plain text", function() {
+		render(root, "a")
+		o(root.childNodes.length).equals(1)
+		o(root.childNodes[0].nodeValue).equals("a")
+	})
+
+	o("updates plain text", function() {
+		render(root, "a")
+		render(root, "b")
+		o(root.childNodes.length).equals(1)
+		o(root.childNodes[0].nodeValue).equals("b")
+	})
+
+	o("renders a number", function() {
+		render(root, 1)
+		o(root.childNodes.length).equals(1)
+		o(root.childNodes[0].nodeValue).equals("1")
+	})
+
+	o("updates a number", function() {
+		render(root, 1)
+		render(root, 2)
+		o(root.childNodes.length).equals(1)
+		o(root.childNodes[0].nodeValue).equals("2")
+	})
+
 	o("overwrites existing content", function() {
 		var vnodes = []