Non array event listeners can be replaced

modules/eventlisteners.js

@@ -4,6 +4,10 @@ function arrInvoker(arr) {
   return function() { arr[0](arr[1]); };
 }
 
+function fnInvoker(arr) {
+  return function(ev) { arr[0](ev); };
+}
+
 function updateEventListeners(oldVnode, vnode) {
   var name, cur, old, elm = vnode.elm,
       oldOn = oldVnode.data.on || {}, on = vnode.data.on;
@@ -12,11 +16,20 @@ function updateEventListeners(oldVnode, vnode) {
     cur = on[name];
     old = oldOn[name];
     if (old === undefined) {
-      elm.addEventListener(name, is.array(cur) ? arrInvoker(cur) : cur);
+      if (is.array(cur)) {
-    } else if (is.array(old)) {
+        elm.addEventListener(name, arrInvoker(cur));
+      } else {
+        cur = [cur];
+        on[name] = cur;
+        elm.addEventListener(name, fnInvoker(cur));
+      }
+    } else if (old.length === 2) {
       old[0] = cur[0]; // Deliberately modify old array since it's
       old[1] = cur[1]; // captured in closure created with `arrInvoker`
       on[name]  = old;
+    } else {
+      old[0] = cur;
+      on[name] = old;
     }
   }
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "snabbdom",
-  "version": "0.1.4",
+  "version": "0.1.5",
   "description": "A virtual DOM library with focus on simplicity, modularity, powerful features and performance.",
   "main": "snabbdom.js",
   "directories": {

test/core.js

@@ -418,16 +418,17 @@ describe('snabbdom', function() {
     it('does not attach new listener', function() {
       var result = [];
       //function clicked(ev) { result.push(ev); }
-      var vnode1 = h('div', {on: {click: function(ev) { result.push(ev); }}}, [
+      var vnode1 = h('div', {on: {click: function(ev) { result.push(1); }}}, [
         h('a', 'Click my parent'),
       ]);
-      var vnode2 = h('div', {on: {click: function(ev) { result.push(ev); }}}, [
+      var vnode2 = h('div', {on: {click: function(ev) { result.push(2); }}}, [
         h('a', 'Click my parent'),
       ]);
       patch(vnode0, vnode1);
+      elm.click();
       patch(vnode1, vnode2);
       elm.click();
-      assert.equal(1, result.length);
+      assert.deepEqual(result, [1, 2]);
     });
     it('does calls handler for function in array', function() {
       var result = [];