Validate the DOM node passed to render

api/tests/test-mount.js

@@ -22,6 +22,16 @@ o.spec("mount", function() {
 		render = coreRenderer($window).render
 	})
 
+	o("throws on invalid `root` DOM node", function() {
+		var threw = false
+		try {
+			mount(null, {view: function() {}})
+		} catch (e) {
+			threw = true
+		}
+		o(threw).equals(true)
+	})
+
 	o("renders into `root`", function() {
 		mount(root, {
 			view : function() {

api/tests/test-router.js

@@ -28,6 +28,16 @@ o.spec("route", function() {
 					route.prefix(prefix)
 				})
 
+				o("throws on invalid `root` DOM node", function() {
+					var threw = false
+					try {
+						route(null, '/', {'/':{view: function() {}}})
+					} catch (e) {
+						threw = true
+					}
+					o(threw).equals(true)
+				})
+
 				o("renders into `root`", function() {
 					$window.location.href = prefix + "/"
 					route(root, "/", {

render/render.js

@@ -515,6 +515,7 @@ module.exports = function($window) {
 	}
 
 	function render(dom, vnodes) {
+		if (!dom) throw new Error("Ensure the DOM element being passed to m.route/m.mount/m.render is not undefined.")
 		var hooks = []
 		var active = $doc.activeElement
 

render/tests/test-render.js

@@ -21,4 +21,13 @@ o.spec("render", function() {
 
 		o(root.childNodes.length).equals(0)
 	})
+	o("throws on invalid root node", function(){
+		var threw = false
+		try {
+			render(null, [])
+		} catch (e) {
+			threw = true
+		}
+		o(threw).equals(true)
+	})
 })