fix: issue #98 setattribute

Author: taoqf

src/nodes/html.ts

@@ -511,7 +511,7 @@ export default class HTMLElement extends Node {
 	}
 
 	public hasAttribute(key: string) {
-		return key in this.attrs;
+		return key.toLowerCase() in this.attrs;
 	}
 
 	/**
@@ -531,10 +531,18 @@ export default class HTMLElement extends Node {
 		if (arguments.length < 2) {
 			throw new Error('Failed to execute \'setAttribute\' on \'Element\'');
 		}
+		const k2 = key.toLowerCase();
 		const attrs = this.rawAttributes;
+		for (const k in attrs) {
+			if (k.toLowerCase() === k2) {
+				key = k;
+				break;
+			}
+		}
 		attrs[key] = String(value);
+		// update this.attrs
 		if (this._attrs) {
-			this._attrs[key] = decode(attrs[key]);
+			this._attrs[k2] = decode(attrs[key]);
 		}
 		// Update rawString
 		this.rawAttrs = Object.keys(attrs).map((name) => {

test/98.js

@@ -14,4 +14,20 @@ describe('getAttribute should be case insensitive', function () {
 		const root = parse('<a onClick="listener()"></a>');
 		root.firstChild.getAttribute('onclick').should.eql('listener()');
 	});
+	it('set attribute in lowercase', function () {
+		const root = parse('<a onClick="listener()"></a>');
+		const a = root.firstChild;
+		a.setAttribute('onclick', 'listener2');
+		a.getAttribute('onclick').should.eql('listener2');
+		root.toString().should.eql('<a onClick="listener2"></a>');
+	});
+	it('add attributes', function () {
+		const root = parse('<a onClick="listener()"></a>');
+		const a = root.firstChild;
+		a.setAttribute('onclick', 'listener2');
+		a.getAttribute('onclick').should.eql('listener2');
+		a.setAttribute('onDoubleClick', 'listener3');
+		a.getAttribute('onDoubleClick').should.eql('listener3');
+		root.toString().should.eql('<a onClick="listener2" onDoubleClick="listener3"></a>');
+	});
 });