-> v0.24.3

add service-worker-index.html

CHANGELOG.md

@@ -1,5 +1,14 @@
 # sapper changelog
 
+## 0.24.3
+
+* Add service-worker-index.html shell file for offline support ([#422](https://github.com/sveltejs/sapper/issues/422))
+* Don't cache .map files ([#534](https://github.com/sveltejs/sapper/issues/534))
+
+## 0.24.2
+
+* Support Rollup 1.0 ([#541](https://github.com/sveltejs/sapper/pull/541))
+
 ## 0.24.1
 
 * Include CSS chunks in webpack build info to avoid duplication ([#529](https://github.com/sveltejs/sapper/pull/529))

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "sapper",
-  "version": "0.24.0",
+  "version": "0.24.2",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -2362,14 +2362,12 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -2384,20 +2382,17 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -2514,8 +2509,7 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "ini": {
           "version": "1.3.5",
@@ -2527,7 +2521,6 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -2542,7 +2535,6 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -2550,14 +2542,12 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "minipass": {
           "version": "2.2.4",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.1",
             "yallist": "^3.0.0"
@@ -2576,7 +2566,6 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -2657,8 +2646,7 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -2670,7 +2658,6 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -2792,7 +2779,6 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "sapper",
-  "version": "0.24.1",
+  "version": "0.24.3",
   "description": "Military-grade apps, engineered by Svelte",
   "bin": {
     "sapper": "./sapper"

src/api/build.ts

@@ -116,10 +116,15 @@ export async function build({
 	let serviceworker_stats;
 
 	if (serviceworker) {
+
+		const client_files = client_result.chunks
+			.filter(chunk => !chunk.file.endsWith('.map')) // SW does not need to cache sourcemap files
+			.map(chunk => `client/${chunk.file}`);
+
 		create_serviceworker_manifest({
 			manifest_data,
 			output,
-			client_files: client_result.chunks.map(chunk => `client/${chunk.file}`),
+			client_files,
 			static_files
 		});
 

src/api/export.ts

@@ -94,7 +94,9 @@ async function _export({
 		const is_html = type === 'text/html';
 
 		if (is_html) {
-			file = file === '' ? 'index.html' : `${file}/index.html`;
+			if (pathname !== '/service-worker-index.html') {
+				file = file === '' ? 'index.html' : `${file}/index.html`;
+			}
 			body = minify_html(body);
 		}
 
@@ -113,7 +115,10 @@ async function _export({
 	});
 
 	async function handle(url: URL) {
-		const pathname = (url.pathname.replace(root.pathname, '') || '/');
+		let pathname = url.pathname;
+		if (pathname !== '/service-worker-index.html') {
+		  pathname = pathname.replace(root.pathname, '') || '/'
+		}
 
 		if (seen.has(pathname)) return;
 		seen.add(pathname);
@@ -138,7 +143,7 @@ async function _export({
 		const range = ~~(r.status / 100);
 
 		if (range === 2) {
-			if (type === 'text/html') {
+			if (type === 'text/html' && pathname !== '/service-worker-index.html') {
 				const urls: URL[] = [];
 
 				const cleaned = clean_html(body);
@@ -181,6 +186,7 @@ async function _export({
 
 	return ports.wait(port)
 		.then(() => handle(root))
+		.then(() => handle(resolve(root.href, 'service-worker-index.html')))
 		.then(() => proc.kill())
 		.catch(err => {
 			proc.kill();

src/core/create_compilers/RollupCompiler.ts

@@ -142,12 +142,14 @@ export default class RollupCompiler {
 
 		const bundle = await rollup.rollup({
 			input,
+			inlineDynamicImports: true,
 			external: (id: string) => {
 				return (id[0] !== '.' && !path.isAbsolute(id)) || id.slice(-5, id.length) === '.json';
 			}
 		});
 
-		const { code } = await bundle.generate({ format: 'cjs' });
+		const resp = await bundle.generate({ format: 'cjs' });
+		const { code } = resp.output ? resp.output[0] : resp;
 
 		// temporarily override require
 		const defaultLoader = require.extensions['.js'];

src/core/create_manifests.ts

@@ -45,17 +45,15 @@ export function create_serviceworker_manifest({ manifest_data, output, client_fi
 	client_files: string[];
 	static_files: string;
 }) {
-	let files: string[];
+	let files: string[] = ['/service-worker-index.html'];
 
 	if (fs.existsSync(static_files)) {
-		files = walk(static_files);
+		files = files.concat(walk(static_files));
 	} else {
 		// TODO remove in a future version
 		if (fs.existsSync('assets')) {
 			throw new Error(`As of Sapper 0.21, the assets/ directory should become static/`);
 		}
-
-		files = [];
 	}
 
 	let code = `

templates/src/server/middleware/get_page_handler.ts

@@ -34,6 +34,7 @@ export function get_page_handler(
 	}
 
 	async function handle_page(page: Page, req: Req, res: Res, status = 200, error: Error | string = null) {
+		const isSWIndexHtml = req.path === '/service-worker-index.html';
 		const build_info: {
 			bundler: 'rollup' | 'webpack',
 			shimport: string | null,
@@ -47,7 +48,7 @@ export function get_page_handler(
 		// preload main.js and current route
 		// TODO detect other stuff we can preload? images, CSS, fonts?
 		let preloaded_chunks = Array.isArray(build_info.assets.main) ? build_info.assets.main : [build_info.assets.main];
-		if (!error) {
+		if (!error && !isSWIndexHtml) {
 			page.parts.forEach(part => {
 				if (!part) return;
 
@@ -145,17 +146,22 @@ export function get_page_handler(
 
 			match = error ? null : page.pattern.exec(req.path);
 
-			preloaded = await Promise.all([root_preloaded].concat(page.parts.map(part => {
-				if (!part) return null;
+			let toPreload = [root_preloaded];
+			if (!isSWIndexHtml) {
+				toPreload = toPreload.concat(page.parts.map(part => {
+					if (!part) return null;
 
-				return part.component.preload
-					? part.component.preload.call(preload_context, {
-						path: req.path,
-						query: req.query,
-						params: part.params ? part.params(match) : {}
-					})
-					: {};
-			})));
+					return part.component.preload
+						? part.component.preload.call(preload_context, {
+							path: req.path,
+							query: req.query,
+							params: part.params ? part.params(match) : {}
+						})
+						: {};
+				}))
+			}
+
+			preloaded = await Promise.all(toPreload);
 		} catch (err) {
 			preload_error = { statusCode: 500, message: err };
 			preloaded = []; // appease TypeScript
@@ -204,23 +210,29 @@ export function get_page_handler(
 			});
 
 			let level = data.child;
-			for (let i = 0; i < page.parts.length; i += 1) {
-				const part = page.parts[i];
-				if (!part) continue;
+			if (isSWIndexHtml) {
+				level.props = Object.assign({}, props, {
+					params: {}
+				})
+			} else {
+				for (let i = 0; i < page.parts.length; i += 1) {
+					const part = page.parts[i];
+					if (!part) continue;
 
-				const get_params = part.params || (() => ({}));
+					const get_params = part.params || (() => ({}));
 
-				Object.assign(level, {
-					component: part.component,
-					props: Object.assign({}, props, {
-						params: get_params(match)
-					}, preloaded[i + 1])
-				});
+					Object.assign(level, {
+						component: part.component,
+						props: Object.assign({}, props, {
+							params: get_params(match)
+						}, preloaded[i + 1])
+					});
 
-				level.props.child = <Props["child"]>{
-					segment: segments[i + 1]
-				};
-				level = level.props.child;
+					level.props.child = <Props["child"]>{
+						segment: segments[i + 1]
+					};
+					level = level.props.child;
+				}
 			}
 
 			const { html, head, css } = manifest.root.render(data, {
@@ -303,6 +315,12 @@ export function get_page_handler(
 	return function find_route(req: Req, res: Res, next: () => void) {
 		if (req[IGNORE]) return next();
 
+		if (req.path === '/service-worker-index.html') {
+			const homePage = pages.find(page => page.pattern.test('/'));
+			handle_page(homePage, req, res);
+			return;
+		}
+
 		if (!server_routes.some(route => route.pattern.test(req.path))) {
 			for (const page of pages) {
 				if (page.pattern.test(req.path)) {

test/apps/export/test.ts

@@ -30,6 +30,7 @@ describe('export', function() {
 			'blog/index.html',
 			'global.css',
 			'index.html',
+			'service-worker-index.html',
 			'service-worker.js'
 		]);
 	});

test/apps/with-basepath/test.ts

@@ -56,6 +56,7 @@ describe('with-basepath', function() {
 		assert.deepEqual(non_client_assets, [
 			'custom-basepath/global.css',
 			'custom-basepath/index.html',
+			'custom-basepath/service-worker-index.html',
 			'custom-basepath/service-worker.js'
 		]);
 	});

test/apps/with-sourcemaps-webpack/src/client.js

@@ -0,0 +1,9 @@
+import * as sapper from '../__sapper__/client.js';
+
+window.start = () => sapper.start({
+	target: document.querySelector('#sapper')
+});
+
+window.prefetchRoutes = () => sapper.prefetchRoutes();
+window.prefetch = href => sapper.prefetch(href);
+window.goto = href => sapper.goto(href);

test/apps/with-sourcemaps-webpack/src/routes/_error.html

@@ -0,0 +1,3 @@
+<h1>{status}</h1>
+
+<p>{error.message}</p>

test/apps/with-sourcemaps-webpack/src/routes/index.html

@@ -0,0 +1,3 @@
+<h1>Great success!</h1>
+
+<p>Woot!</p>

test/apps/with-sourcemaps-webpack/src/server.js

@@ -0,0 +1,8 @@
+import polka from 'polka';
+import * as sapper from '../__sapper__/server.js';
+
+const { PORT } = process.env;
+
+polka()
+	.use(sapper.middleware())
+	.listen(PORT);

test/apps/with-sourcemaps-webpack/src/service-worker.js

@@ -0,0 +1,82 @@
+import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+
+const ASSETS = `cache${timestamp}`;
+
+// `shell` is an array of all the files generated by webpack,
+// `files` is an array of everything in the `static` directory
+const to_cache = shell.concat(ASSETS);
+const cached = new Set(to_cache);
+
+self.addEventListener('install', event => {
+	event.waitUntil(
+		caches
+			.open(ASSETS)
+			.then(cache => cache.addAll(to_cache))
+			.then(() => {
+				self.skipWaiting();
+			})
+	);
+});
+
+self.addEventListener('activate', event => {
+	event.waitUntil(
+		caches.keys().then(async keys => {
+			// delete old caches
+			for (const key of keys) {
+				if (key !== ASSETS) await caches.delete(key);
+			}
+
+			self.clients.claim();
+		})
+	);
+});
+
+self.addEventListener('fetch', event => {
+	if (event.request.method !== 'GET') return;
+
+	const url = new URL(event.request.url);
+
+	// don't try to handle e.g. data: URIs
+	if (!url.protocol.startsWith('http')) return;
+
+	// ignore dev server requests
+	if (url.hostname === self.location.hostname && url.port !== self.location.port) return;
+
+	// always serve assets and webpack-generated files from cache
+	if (url.host === self.location.host && cached.has(url.pathname)) {
+		event.respondWith(caches.match(event.request));
+		return;
+	}
+
+	// for pages, you might want to serve a shell `index.html` file,
+	// which Sapper has generated for you. It's not right for every
+	// app, but if it's right for yours then uncomment this section
+	/*
+	if (url.origin === self.origin && routes.find(route => route.pattern.test(url.pathname))) {
+		event.respondWith(caches.match('/index.html'));
+		return;
+	}
+	*/
+
+	if (event.request.cache === 'only-if-cached') return;
+
+	// for everything else, try the network first, falling back to
+	// cache if the user is offline. (If the pages never change, you
+	// might prefer a cache-first approach to a network-first one.)
+	event.respondWith(
+		caches
+			.open(`offline${timestamp}`)
+			.then(async cache => {
+				try {
+					const response = await fetch(event.request);
+					cache.put(event.request, response.clone());
+					return response;
+				} catch(err) {
+					const response = await cache.match(event.request);
+					if (response) return response;
+
+					throw err;
+				}
+			})
+	);
+});

test/apps/with-sourcemaps-webpack/src/template.html

@@ -0,0 +1,14 @@
+<!doctype html>
+<html lang="en">
+<head>
+	<meta charset='utf-8'>
+
+	%sapper.base%
+	%sapper.styles%
+	%sapper.head%
+</head>
+<body>
+	<div id='sapper'>%sapper.html%</div>
+	%sapper.scripts%
+</body>
+</html>

test/apps/with-sourcemaps-webpack/test.ts

@@ -0,0 +1,43 @@
+import * as puppeteer from 'puppeteer';
+import { build } from '../../../api';
+import * as assert from "assert";
+import { AppRunner } from '../AppRunner';
+import * as fs from "fs";
+import * as path from "path";
+
+describe('with-sourcemaps-webpack', function() {
+	this.timeout(10000);
+
+	let runner: AppRunner;
+	let page: puppeteer.Page;
+	let base: string;
+
+	// helpers
+	let start: () => Promise<void>;
+	let prefetchRoutes: () => Promise<void>;
+	let prefetch: (href: string) => Promise<void>;
+	let goto: (href: string) => Promise<void>;
+
+	// hooks
+	before(async () => {
+		await build({ cwd: __dirname, bundler: 'webpack' });
+
+		runner = new AppRunner(__dirname, '__sapper__/build/server/server.js');
+		({ base, page, start, prefetchRoutes, prefetch, goto } = await runner.start());
+	});
+
+	it('does not put sourcemap files in service worker shell', async () => {
+		const serviceWorker = await import(`${__dirname}/__sapper__/service-worker.js`);
+		const shell: string[] = serviceWorker.shell;
+
+		assert.equal(shell.filter(_ => _.endsWith('.map')).length, 0,
+			'sourcemap files are not cached in SW');
+
+		const clientShellDir = path.resolve(`${__dirname}/__sapper__/build`, path.dirname(shell[0]));
+		const sourcemapFiles = fs.readdirSync(clientShellDir).filter(_ => _.endsWith('.map'));
+		assert.ok(sourcemapFiles.length > 0, 'sourcemap files exist');
+	});
+
+	after(() => runner.end());
+
+});

test/apps/with-sourcemaps-webpack/webpack.config.js

@@ -0,0 +1,73 @@
+const webpack = require('webpack');
+const config = require('../../../config/webpack.js');
+
+const mode = process.env.NODE_ENV;
+const dev = mode === 'development';
+
+module.exports = {
+	client: {
+		entry: config.client.entry(),
+		output: config.client.output(),
+		resolve: {
+			extensions: ['.js', '.json', '.html'],
+			mainFields: ['svelte', 'module', 'browser', 'main']
+		},
+		module: {
+			rules: [
+				{
+					test: /\.html$/,
+					use: {
+						loader: 'svelte-loader',
+						options: {
+							dev,
+							hydratable: true,
+							hotReload: true
+						}
+					}
+				}
+			]
+		},
+		mode,
+		plugins: [
+			dev && new webpack.HotModuleReplacementPlugin(),
+			new webpack.DefinePlugin({
+				'process.browser': true,
+				'process.env.NODE_ENV': JSON.stringify(mode)
+			}),
+		].filter(Boolean),
+		devtool: dev ? 'inline-source-map' : 'source-map'
+	},
+
+	server: {
+		entry: config.server.entry(),
+		output: config.server.output(),
+		target: 'node',
+		resolve: {
+			extensions: ['.js', '.json', '.html'],
+			mainFields: ['svelte', 'module', 'browser', 'main']
+		},
+		module: {
+			rules: [
+				{
+					test: /\.html$/,
+					use: {
+						loader: 'svelte-loader',
+						options: {
+							css: false,
+							generate: 'ssr',
+							dev
+						}
+					}
+				}
+			]
+		},
+		mode: process.env.NODE_ENV
+	},
+
+	serviceworker: {
+		entry: config.serviceworker.entry(),
+		output: config.serviceworker.output(),
+		mode: process.env.NODE_ENV,
+		devtool: 'sourcemap'
+	}
+};

test/apps/with-sourcemaps/rollup.config.js

@@ -0,0 +1,64 @@
+import resolve from 'rollup-plugin-node-resolve';
+import replace from 'rollup-plugin-replace';
+import svelte from 'rollup-plugin-svelte';
+
+const mode = process.env.NODE_ENV;
+const dev = mode === 'development';
+
+const config = require('../../../config/rollup.js');
+
+export default {
+	client: {
+		input: config.client.input(),
+		output: Object.assign({}, config.client.output(), { sourcemap: true }),
+		plugins: [
+			replace({
+				'process.browser': true,
+				'process.env.NODE_ENV': JSON.stringify(mode)
+			}),
+			svelte({
+				dev,
+				hydratable: true,
+				emitCss: true
+			}),
+			resolve()
+		],
+
+		// temporary, pending Rollup 1.0
+		experimentalCodeSplitting: true
+	},
+
+	server: {
+		input: config.server.input(),
+		output: config.server.output(),
+		plugins: [
+			replace({
+				'process.browser': false,
+				'process.env.NODE_ENV': JSON.stringify(mode)
+			}),
+			svelte({
+				generate: 'ssr',
+				dev
+			}),
+			resolve({
+				preferBuiltins: true
+			})
+		],
+		external: ['sirv', 'polka'],
+
+		// temporary, pending Rollup 1.0
+		experimentalCodeSplitting: true
+	},
+
+	serviceworker: {
+		input: config.serviceworker.input(),
+		output: config.serviceworker.output(),
+		plugins: [
+			resolve(),
+			replace({
+				'process.browser': true,
+				'process.env.NODE_ENV': JSON.stringify(mode)
+			})
+		]
+	}
+};

test/apps/with-sourcemaps/src/client.js

@@ -0,0 +1,9 @@
+import * as sapper from '../__sapper__/client.js';
+
+window.start = () => sapper.start({
+	target: document.querySelector('#sapper')
+});
+
+window.prefetchRoutes = () => sapper.prefetchRoutes();
+window.prefetch = href => sapper.prefetch(href);
+window.goto = href => sapper.goto(href);

test/apps/with-sourcemaps/src/routes/_error.html

@@ -0,0 +1,3 @@
+<h1>{status}</h1>
+
+<p>{error.message}</p>

test/apps/with-sourcemaps/src/routes/index.html

@@ -0,0 +1,3 @@
+<h1>Great success!</h1>
+
+<p>Woot!</p>

test/apps/with-sourcemaps/src/server.js

@@ -0,0 +1,8 @@
+import polka from 'polka';
+import * as sapper from '../__sapper__/server.js';
+
+const { PORT } = process.env;
+
+polka()
+	.use(sapper.middleware())
+	.listen(PORT);

test/apps/with-sourcemaps/src/service-worker.js

@@ -0,0 +1,82 @@
+import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+
+const ASSETS = `cache${timestamp}`;
+
+// `shell` is an array of all the files generated by webpack,
+// `files` is an array of everything in the `static` directory
+const to_cache = shell.concat(ASSETS);
+const cached = new Set(to_cache);
+
+self.addEventListener('install', event => {
+	event.waitUntil(
+		caches
+			.open(ASSETS)
+			.then(cache => cache.addAll(to_cache))
+			.then(() => {
+				self.skipWaiting();
+			})
+	);
+});
+
+self.addEventListener('activate', event => {
+	event.waitUntil(
+		caches.keys().then(async keys => {
+			// delete old caches
+			for (const key of keys) {
+				if (key !== ASSETS) await caches.delete(key);
+			}
+
+			self.clients.claim();
+		})
+	);
+});
+
+self.addEventListener('fetch', event => {
+	if (event.request.method !== 'GET') return;
+
+	const url = new URL(event.request.url);
+
+	// don't try to handle e.g. data: URIs
+	if (!url.protocol.startsWith('http')) return;
+
+	// ignore dev server requests
+	if (url.hostname === self.location.hostname && url.port !== self.location.port) return;
+
+	// always serve assets and webpack-generated files from cache
+	if (url.host === self.location.host && cached.has(url.pathname)) {
+		event.respondWith(caches.match(event.request));
+		return;
+	}
+
+	// for pages, you might want to serve a shell `index.html` file,
+	// which Sapper has generated for you. It's not right for every
+	// app, but if it's right for yours then uncomment this section
+	/*
+	if (url.origin === self.origin && routes.find(route => route.pattern.test(url.pathname))) {
+		event.respondWith(caches.match('/index.html'));
+		return;
+	}
+	*/
+
+	if (event.request.cache === 'only-if-cached') return;
+
+	// for everything else, try the network first, falling back to
+	// cache if the user is offline. (If the pages never change, you
+	// might prefer a cache-first approach to a network-first one.)
+	event.respondWith(
+		caches
+			.open(`offline${timestamp}`)
+			.then(async cache => {
+				try {
+					const response = await fetch(event.request);
+					cache.put(event.request, response.clone());
+					return response;
+				} catch(err) {
+					const response = await cache.match(event.request);
+					if (response) return response;
+
+					throw err;
+				}
+			})
+	);
+});

test/apps/with-sourcemaps/src/template.html

@@ -0,0 +1,14 @@
+<!doctype html>
+<html lang="en">
+<head>
+	<meta charset='utf-8'>
+
+	%sapper.base%
+	%sapper.styles%
+	%sapper.head%
+</head>
+<body>
+	<div id='sapper'>%sapper.html%</div>
+	%sapper.scripts%
+</body>
+</html>

test/apps/with-sourcemaps/test.ts

@@ -0,0 +1,43 @@
+import * as puppeteer from 'puppeteer';
+import { build } from '../../../api';
+import * as assert from "assert";
+import { AppRunner } from '../AppRunner';
+import * as fs from 'fs';
+import * as path from "path";
+
+describe('with-sourcemaps', function() {
+	this.timeout(10000);
+
+	let runner: AppRunner;
+	let page: puppeteer.Page;
+	let base: string;
+
+	// helpers
+	let start: () => Promise<void>;
+	let prefetchRoutes: () => Promise<void>;
+	let prefetch: (href: string) => Promise<void>;
+	let goto: (href: string) => Promise<void>;
+
+	// hooks
+	before(async () => {
+		await build({ cwd: __dirname });
+
+		runner = new AppRunner(__dirname, '__sapper__/build/server/server.js');
+		({ base, page, start, prefetchRoutes, prefetch, goto } = await runner.start());
+	});
+
+	it('does not put sourcemap files in service worker shell', async () => {
+		const serviceWorker = await import(`${__dirname}/__sapper__/service-worker.js`);
+		const shell: string[] = serviceWorker.shell;
+
+		assert.equal(shell.filter(_ => _.endsWith('.map')).length, 0,
+			'sourcemap files are not cached in SW');
+
+		const clientShellDir = path.resolve(`${__dirname}/__sapper__/build`, path.dirname(shell[0]));
+		const sourcemapFiles = fs.readdirSync(clientShellDir).filter(_ => _.endsWith('.map'));
+		assert.ok(sourcemapFiles.length > 0, 'sourcemap files exist');
+	});
+
+	after(() => runner.end());
+
+});