Improve internal API

test/apps/scroll/test.ts

@@ -0,0 +1,62 @@
+import * as assert from 'assert';
+import * as puppeteer from 'puppeteer';
+import { build } from '../../../api';
+import { AppRunner } from '../AppRunner';
+import { wait } from '../../utils';
+
+describe('scroll', function() {
+	this.timeout(10000);
+
+	let runner: AppRunner;
+	let page: puppeteer.Page;
+	let base: string;
+
+	// helpers
+	let start: () => Promise<void>;
+	let prefetchRoutes: () => Promise<void>;
+
+	// hooks
+	before(async () => {
+		await build({ cwd: __dirname });
+
+		runner = new AppRunner(__dirname, '__sapper__/build/server/server.js');
+		({ base, page, start, prefetchRoutes } = await runner.start());
+	});
+
+	after(() => runner.end());
+
+	it('scrolls to active deeplink', async () => {
+		await page.goto(`${base}/tall-page#foo`);
+		await start();
+
+		const scrollY = await page.evaluate(() => window.scrollY);
+		assert.ok(scrollY > 0, scrollY);
+	});
+
+	it('resets scroll when a link is clicked', async () => {
+		await page.goto(`${base}/tall-page#foo`);
+		await start();
+		await prefetchRoutes();
+
+		await page.click('[href="another-tall-page"]');
+		await wait(50);
+
+		assert.equal(
+			await page.evaluate(() => window.scrollY),
+			0
+		);
+	});
+
+	it('preserves scroll when a link with sapper-noscroll is clicked', async () => {
+		await page.goto(`${base}/tall-page#foo`);
+		await start();
+		await prefetchRoutes();
+
+		await page.click('[href="another-tall-page"][sapper-noscroll]');
+		await wait(50);
+
+		const scrollY = await page.evaluate(() => window.scrollY);
+
+		assert.ok(scrollY > 0);
+	});
+});