Improve internal API

test/apps/preloading/test.ts

@@ -0,0 +1,86 @@
+import * as path from 'path';
+import * as assert from 'assert';
+import * as puppeteer from 'puppeteer';
+import { build } from '../../../api';
+import { wait } from '../../utils';
+import { AppRunner } from '../AppRunner';
+
+declare const fulfil: () => Promise<void>;
+
+describe('preloading', 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());
+
+	const title = () => page.$eval('h1', node => node.textContent);
+
+	it('serializes Set objects returned from preload', async () => {
+		await page.goto(`${base}/preload-values/set`);
+
+		assert.equal(await title(), 'true');
+
+		await start();
+		assert.equal(await title(), 'true');
+	});
+
+	it('bails on custom classes returned from preload', async () => {
+		await page.goto(`${base}/preload-values/custom-class`);
+
+		assert.equal(await title(), '42');
+
+		await start();
+		assert.equal(await title(), '42');
+	});
+
+	it('sets preloading true when appropriate', async () => {
+		await page.goto(base);
+		await start();
+		await prefetchRoutes();
+
+		await page.click('a[href="slow-preload"]');
+
+		assert.ok(await page.evaluate(() => !!document.querySelector('progress')));
+
+		await page.evaluate(() => fulfil());
+		assert.ok(await page.evaluate(() => !document.querySelector('progress')));
+	});
+
+	it('runs preload in root component', async () => {
+		await page.goto(`${base}/preload-root`);
+		assert.equal(await title(), 'root preload function ran: true');
+	});
+
+	it('cancels navigation if subsequent navigation occurs during preload', async () => {
+		await page.goto(base);
+		await start();
+		await prefetchRoutes();
+
+		await page.click('a[href="slow-preload"]');
+		await wait(100);
+		await page.click('a[href="foo"]');
+
+		assert.equal(page.url(), `${base}/foo`);
+		assert.equal(await title(), 'foo');
+
+		await page.evaluate(() => fulfil());
+		await wait(100);
+		assert.equal(page.url(), `${base}/foo`);
+		assert.equal(await title(), 'foo');
+	});
+});