[render/hyperscript] Normalize to class attrs to className, ignore only nullish values

render/hyperscript.js

@@ -51,15 +51,17 @@ function execSelector(state, attrs, children) {
 			attrs[key] = state.attrs[key]
 		}
 	}
-	if (className || state.attrs.className) attrs[classAttr] =
-		className
-			? state.attrs.className
+	if (className != null || state.attrs.className != null) attrs.className =
+		className != null
+			? state.attrs.className != null
 				? state.attrs.className + " " + className
 				: className
-			: state.attrs.className
+			: state.attrs.className != null
 				? state.attrs.className
 				: null
 
+	if (classAttr === "class") attrs.class = null
+
 	for (var key in attrs) {
 		if (hasOwn.call(attrs, key) && key !== "key") {
 			hasAttrs = true

render/tests/test-hyperscript.js

@@ -25,37 +25,43 @@ o.spec("hyperscript", function() {
 			o(m("a", {
 				class: undefined
 			}).attrs).deepEquals({
-				class: undefined
+				class: null
 			})
 			o(m("a", {
 				class: false
 			}).attrs).deepEquals({
-				class: false
+				class: null,
+				className: false
 			})
 			o(m("a", {
 				class: true
 			}).attrs).deepEquals({
-				class: true
+				class: null,
+				className: true
 			})
 			o(m("a.x", {
 				class: null
 			}).attrs).deepEquals({
-				class: "x"
+				class: null,
+				className: "x"
 			})
 			o(m("a.x", {
 				class: undefined
 			}).attrs).deepEquals({
-				class: "x"
+				class: null,
+				className: "x"
 			})
 			o(m("a.x", {
 				class: false
 			}).attrs).deepEquals({
-				class: "x"
+				class: null,
+				className: "x false"
 			})
 			o(m("a.x", {
 				class: true
 			}).attrs).deepEquals({
-				class: "x true"
+				class: null,
+				className: "x true"
 			})
 			o(m("a", {
 				className: null
@@ -90,7 +96,7 @@ o.spec("hyperscript", function() {
 			o(m("a.x", {
 				className: false
 			}).attrs).deepEquals({
-				className: "x"
+				className: "x false"
 			})
 			o(m("a.x", {
 				className: true
@@ -288,7 +294,7 @@ o.spec("hyperscript", function() {
 		o("handles merging classes w/ class property", function() {
 			var vnode = m(".a", {class: "b"})
 
-			o(vnode.attrs.class).equals("a b")
+			o(vnode.attrs.className).equals("a b")
 		})
 		o("handles merging classes w/ className property", function() {
 			var vnode = m(".a", {className: "b"})