merge master -> gh-49

test/app/routes/_components/Nav.html

@@ -1,10 +1,8 @@
 <nav>
 	<ul>
-		<li><a class='{{page === "home"  ? "selected" : ""}}' href='/'>home</a></li>
-		<li><a class='{{page === "about"  ? "selected" : ""}}' href='/about'>about</a></li>
-
-		<!-- for the blog link, we're using rel=prefetch so that Sapper prefetches
-		     the blog data when we hover over the link or tap it on a touchscreen -->
+		<li><a href='/'>home</a></li>
+		<li><a href='/about'>about</a></li>
+		<li><a href='/slow-preload'>slow preload</a></li>
 		<li><a rel=prefetch class='{{page === "blog"  ? "selected" : ""}}' href='/blog'>blog</a></li>
 	</ul>
 </nav>

test/app/routes/about.html

@@ -12,7 +12,7 @@
 
 <script>
 	import Layout from './_components/Layout.html';
-	import { goto } from '../../../runtime/app.js';
+	import { goto } from '../../../runtime.js';
 
 	export default {
 		components: {

test/app/routes/slow-preload.html

@@ -0,0 +1,11 @@
+<h1>This page should never render</h1>
+
+<script>
+	export default {
+		preload() {
+			return new Promise(fulfil => {
+				window.fulfil = fulfil;
+			});
+		}
+	};
+</script>

test/app/templates/main.js

@@ -1,4 +1,4 @@
-import { init } from '../../../runtime/app.js';
+import { init } from '../../../runtime.js';
 
 // `routes` is an array of route objects injected by Sapper
 init(document.querySelector('#sapper'), __routes__);

test/common/test.js

@@ -233,6 +233,40 @@ function run(env) {
 
 				assert.deepEqual(click_requests, []);
 			});
+
+			it('cancels navigation if subsequent navigation occurs during preload', async () => {
+				await nightmare
+					.goto(base)
+					.wait(() => window.READY)
+					.click('a[href="/slow-preload"]')
+					.wait(100)
+					.click('a[href="/about"]')
+					.wait(100);
+
+				assert.equal(
+					await nightmare.path(),
+					'/about'
+				);
+
+				assert.equal(
+					await nightmare.evaluate(() => document.querySelector('h1').textContent),
+					'About this site'
+				);
+
+				await nightmare
+					.evaluate(() => window.fulfil({}))
+					.wait(100);
+
+				assert.equal(
+					await nightmare.path(),
+					'/about'
+				);
+
+				assert.equal(
+					await nightmare.evaluate(() => document.querySelector('h1').textContent),
+					'About this site'
+				);
+			});
 		});
 
 		describe('headers', () => {