Adds boolean attribute support.

Also includes the following major change:
	- Stops unconditionally creating a `className` attribute on DOM nodes.

lib/index.js

@@ -259,13 +259,22 @@ function htmlEscape(content) {
 /* Renders a singleton attribute key, or a key-value attribute pair,
  * HTML-escaping the value. */
 function renderAttribute(key, value) {
-	if (!value) {
-		return key;
+	var isBoolAttr = isBooleanAttribute(key);
+
+	if (isBoolAttr && value === true) {
+		return key + '="' + key + '"';
+	} else if (isBoolAttr && value === false) {
+		return '';
 	} else {
 		return key + '="' + htmlEscape(value) + '"';
 	}
 }
 
+// https://github.com/kangax/html-minifier/issues/63#issuecomment-37763316
+function isBooleanAttribute(attribute) {
+    return (/^(?:allowFullscreen|async|autofocus|autoplay|checked|compact|controls|declare|default|defaultChecked|defaultMuted|defaultSelected|defer|disabled|draggable|enabled|formNoValidate|hidden|indeterminate|inert|isMap|itemScope|loop|multiple|muted|noHref|noResize|noShade|noValidate|noWrap|open|pauseOnExit|readOnly|required|reversed|scoped|seamless|selected|sortable|spellcheck|translate|trueSpeed|typeMustMatch|visible)$/).test(attribute);
+}
+
 function renderStyle(style) {
 	return Object.keys(style).reduce(function styler(styleString, property) {
 		return styleString + property + ':' + style[property] + ';';
@@ -295,9 +304,10 @@ Node.prototype.render = function render() {
 		// It is still possible for a void node to be given children:
 		// in such a case, their children are iterated upon anyway.
 		// Browsers allow this behavior, so it is allowed here.
-		(!node.isVoid || !(node.children.length === 0) ? childContents +
-			'</' + node.name + '>' :
-		'');
+		(!node.isVoid || !(node.children.length === 0) ?
+			 childContents +
+			 '</' + node.name + '>' :
+			 '');
 };
 
 /* Renders a list of nodes into an HTML string. */
@@ -320,14 +330,29 @@ Node.prototype.toDOM = function toDOM(document_) {
 	var root = document_.createElement(node.name);
 
 	Object.keys(node.attributes).forEach(function setAttr(key) {
-		root.setAttribute(key, node.attributes[key]);
+		var value = node.attributes[key];
+
+		var isBoolAttr = isBooleanAttribute(key);
+
+		// If a known-boolean attribute from the HTML5 spec is
+		// encountered, it is displayed or not displayed based on
+		// whether it is `true` or `false`. All other values (including
+		// other falsy ones) are passed-through (and converted into
+		// strings):
+		if (isBoolAttr && value === true) {
+			root.setAttribute(key, key);
+		} else if (isBoolAttr && value === false) {
+			// NOP
+		} else {
+			root.setAttribute(key, value);
+		}
 	});
 
 	if (node.id) {
 		root.id = node.id;
 	}
 
-	if (Array.isArray(node.class)) {
+	if (node.class.length > 0) {
 		root.className = node.class.join(' ');
 	}
 
@@ -368,7 +393,7 @@ Node.appendListToDOM = function appendListToDOM(parent, nodeList, document_) {
 
 return Node;
 
-}));
 // And without faith it is impossible to please God, because anyone who comes
 // to Him must believe that He exists and that He rewards those who earnestly
 // seek Him. - Hebrews 11:6
+}));

package.json

@@ -1,6 +1,6 @@
 {
   "name": "lmth",
-  "version": "3.0.0",
+  "version": "4.0.0",
   "description": "A \"type-safe\" HTML DSL for JavaScript environments.",
   "main": "lib/index.js",
   "scripts": {