[refactor] performance improvement by replacing #2622 fix in render.j…

…s with another workaround in hyperscript.js

The input[type] inspection at the beginning of setAttr() was called for each attribute. This had a negative impact on performance. The new workaround in execSelector() controls the order of setting attributes by reordering the keys in attrs.

render/hyperscript.js

@@ -56,6 +56,13 @@ function execSelector(state, vnode) {
 
 	if (hasClass) attrs.class = null
 
+	// workaround for #2622 (reorder keys in attrs to set "type" first)
+	// The DOM does things to inputs based on the "type", so it needs set first.
+	// See: https://github.com/MithrilJS/mithril.js/issues/2622
+	if (state.tag === "input" && hasOwn.call(attrs, "type")) {
+		attrs = assign({type: attrs.type}, attrs)
+	}
+
 	vnode.attrs = attrs
 
 	return vnode

render/render.js

@@ -671,18 +671,13 @@ module.exports = function() {
 
 	//attrs
 	function setAttrs(vnode, attrs, ns) {
-		// If you assign an input type that is not supported by IE 11 with an assignment expression, an error will occur.
-		//
-		// Also, the DOM does things to inputs based on the value, so it needs set first.
-		// See: https://github.com/MithrilJS/mithril.js/issues/2622
-		if (vnode.tag === "input" && attrs.type != null) vnode.dom.setAttribute("type", attrs.type)
 		var isFileInput = attrs != null && vnode.tag === "input" && attrs.type === "file"
 		for (var key in attrs) {
 			setAttr(vnode, key, null, attrs[key], ns, isFileInput)
 		}
 	}
 	function setAttr(vnode, key, old, value, ns, isFileInput) {
-		if (key === "key" || key === "is" || value == null || isLifecycleMethod(key) || (old === value && !isFormAttribute(vnode, key)) && typeof value !== "object" || key === "type" && vnode.tag === "input") return
+		if (key === "key" || key === "is" || value == null || isLifecycleMethod(key) || (old === value && !isFormAttribute(vnode, key)) && typeof value !== "object") return
 		if (key[0] === "o" && key[1] === "n") return updateEvent(vnode, key, value)
 		if (key.slice(0, 6) === "xlink:") vnode.dom.setAttributeNS("http://www.w3.org/1999/xlink", key.slice(6), value)
 		else if (key === "style") updateStyle(vnode.dom, old, value)
@@ -702,7 +697,9 @@ module.exports = function() {
 				if (isFileInput && "" + value !== "") { console.error("`value` is read-only on file inputs!"); return }
 				/* eslint-enable no-implicit-coercion */
 			}
-			vnode.dom[key] = value
+			// If you assign an input type that is not supported by IE 11 with an assignment expression, an error will occur.
+			if (vnode.tag === "input" && key === "type") vnode.dom.setAttribute(key, value)
+			else vnode.dom[key] = value
 		} else {
 			if (typeof value === "boolean") {
 				if (value) vnode.dom.setAttribute(key, "")
@@ -750,11 +747,6 @@ module.exports = function() {
 			console.warn("Don't reuse attrs object, use new object for every redraw, this will throw in next major")
 		}
 		if (attrs != null) {
-			// If you assign an input type that is not supported by IE 11 with an assignment expression, an error will occur.
-			//
-			// Also, the DOM does things to inputs based on the value, so it needs set first.
-			// See: https://github.com/MithrilJS/mithril.js/issues/2622
-			if (vnode.tag === "input" && attrs.type != null) vnode.dom.setAttribute("type", attrs.type)
 			var isFileInput = vnode.tag === "input" && attrs.type === "file"
 			for (var key in attrs) {
 				setAttr(vnode, key, old && old[key], attrs[key], ns, isFileInput)