add getAttribute

src/nodes/html.ts

@@ -431,6 +431,14 @@ export default class HTMLElement extends Node {
 		return attrs;
 	}
 
+	/**
+	 * Get an attribute
+	 * @return {string} value of the attribute
+	 */
+	getAttribute(key: string) {
+		return this.attributes[key] || null;
+	}
+
 	/**
 	 * Set an attribute value to the HTMLElement
 	 * @param {string} key The attribute name

test/html.js

@@ -319,6 +319,18 @@ describe('HTML Parser', function () {
 			});
 		});
 
+		describe('#getAttribute', function () {
+			it('should return value of the attribute', function () {
+				var root = parseHTML('<p a="a1b"></p>');
+				root.firstChild.getAttribute('a').should.eql('a1b');
+			});
+
+			it('should return null when there is no such attribute', function () {
+				var root = parseHTML('<p></p>');
+				should.equal(root.firstChild.getAttribute('b'), null);
+			});
+		});
+
 		describe('#setAttribute', function () {
 			it('should edit the attributes of the element', function () {
 				var root = parseHTML('<p a=12></p>');