Added options.preprocess and tests

runtime/src/server/middleware/get_page_handler.ts

@@ -11,7 +11,8 @@ import App from '@sapper/internal/App.svelte';
 
 export function get_page_handler(
 	manifest: Manifest,
-	session_getter: (req: Req, res: Res) => any
+	session_getter: (req: Req, res: Res) => any,
+	preprocess: (body: String, req: Req, res: Res) => any
 ) {
 	const get_build_info = dev
 		? () => JSON.parse(fs.readFileSync(path.join(build_dir, 'build.json'), 'utf-8'))
@@ -320,13 +321,15 @@ export function get_page_handler(
 			// users can set a CSP nonce using res.locals.nonce
 			const nonce_attr = (res.locals && res.locals.nonce) ? ` nonce="${res.locals.nonce}"` : '';
 
-			const body = template()
+			let body = template()
 				.replace('%sapper.base%', () => `<base href="${req.baseUrl}/">`)
 				.replace('%sapper.scripts%', () => `<script${nonce_attr}>${script}</script>`)
 				.replace('%sapper.html%', () => html)
 				.replace('%sapper.head%', () => `<noscript id='sapper-head-start'></noscript>${head}<noscript id='sapper-head-end'></noscript>`)
 				.replace('%sapper.styles%', () => styles);
 
+			body = preprocess(body, req, res) || body;
+
 			res.statusCode = status;
 			res.end(body);
 		} catch(err) {

runtime/src/server/middleware/index.ts

@@ -10,7 +10,7 @@ export default function middleware(opts: {
 	session?: (req: Req, res: Res) => any,
 	ignore?: any
 } = {}) {
-	const { session, ignore } = opts;
+	const { session, ignore, preprocess } = opts;
 
 	let emitted_basepath = false;
 
@@ -61,7 +61,7 @@ export default function middleware(opts: {
 
 		get_server_route_handler(manifest.server_routes),
 
-		get_page_handler(manifest, session || noop)
+		get_page_handler(manifest, session || noop, preprocess || noop)
 	].filter(Boolean));
 }
 

test/apps/preprocess/rollup.config.js

@@ -0,0 +1,58 @@
+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: config.client.output(),
+		plugins: [
+			replace({
+				'process.browser': true,
+				'process.env.NODE_ENV': JSON.stringify(mode)
+			}),
+			svelte({
+				dev,
+				hydratable: true,
+				emitCss: true
+			}),
+			resolve()
+		]
+	},
+
+	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']
+	},
+
+	serviceworker: {
+		input: config.serviceworker.input(),
+		output: config.serviceworker.output(),
+		plugins: [
+			resolve(),
+			replace({
+				'process.browser': true,
+				'process.env.NODE_ENV': JSON.stringify(mode)
+			})
+		]
+	}
+};

test/apps/preprocess/src/client.js

@@ -0,0 +1,9 @@
+import * as sapper from '@sapper/app';
+
+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/preprocess/src/routes/_error.svelte

@@ -0,0 +1,8 @@
+<script>
+	export let status;
+	export let error;
+</script>
+
+<h1>{status}</h1>
+
+<p>{error.message}</p>

test/apps/preprocess/src/routes/index.svelte

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

test/apps/preprocess/src/server.js

@@ -0,0 +1,15 @@
+import polka from 'polka';
+import * as sapper from '@sapper/server';
+
+import { start } from '../../common.js';
+
+const app = polka()
+	.use(
+		sapper.middleware({
+			preprocess: (body) => {
+				return body.replace('%custom.data%', '<div id="test">works!</div>');
+			}
+		})
+	);
+
+start(app);

test/apps/preprocess/src/service-worker.js

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