Update to preact 8, add test & fix for null child issue

Author: developit

package.json

@@ -46,7 +46,7 @@
     "chai": "^3.5.0",
     "eslint": "^3.2.2",
     "mocha": "^3.0.0",
-    "preact": "^7.1.0",
+    "preact": "^8.1.0",
     "rollup": "^0.34.3",
     "rollup-plugin-babel": "^2.6.1",
     "rollup-plugin-commonjs": "^3.3.1",

src/index.js

@@ -181,7 +181,7 @@ export default function renderToString(vnode, context, opts, inner, isSvgMode) {
 				let childSvgMode = nodeName==='svg' ? true : nodeName==='foreignObject' ? false : isSvgMode,
 					ret = renderToString(child, context, opts, true, childSvgMode);
 				if (!hasLarge && pretty && isLargeString(ret)) hasLarge = true;
-				pieces.push(ret);
+				if (ret) pieces.push(ret);
 			}
 		}
 		if (hasLarge) {

test/jsx.js

@@ -96,7 +96,7 @@ describe('jsx', () => {
 			<a b={undefined}>bar</a>
 		)).to.equal(`<a>bar</a>`);
 	});
-
+	
 	it('should render attributes containing VNodes', () => {
 		expect(renderJsx(
 			<a b={<c />}>bar</a>
@@ -145,6 +145,19 @@ describe('jsx', () => {
 		`);
 	});
 
+	it('should skip null siblings', () => {
+		expect(renderJsx(
+			<jsx>
+				<span/>
+				{null}
+			</jsx>
+		)).to.deep.equal(dedent`
+			<jsx>
+				<span></span>
+			</jsx>
+		`);
+	});
+
 	it('should skip functions if functions=false', () => {
 		expect(renderJsx(
 			<div onClick={() => {}} />,