print warnings in dev mode for unused data

.travis.yml

@@ -18,4 +18,4 @@ addons:
 install:
   - export DISPLAY=':99.0'
   - Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
-  - npm ci || npm i
+  - npm install

CHANGELOG.md

@@ -1,31 +1,5 @@
 # sapper changelog
 
-## 0.17.0
-
-* Use `cheap-watch` instead of `chokidar` ([#364](https://github.com/sveltejs/sapper/issues/364))
-
-## 0.16.1
-
-* Fix file watching regression in previous version
-
-## 0.16.0
-
-* Slim down installed package ([#363](https://github.com/sveltejs/sapper/pull/363))
-
-## 0.15.8
-
-* Only set `preloading: true` on navigation, not prefetch ([#352](https://github.com/sveltejs/sapper/issues/352))
-* Provide fallback for missing preload errors ([#361](https://github.com/sveltejs/sapper/pull/361))
-
-## 0.15.7
-
-* Strip leading slash from redirects ([#291](https://github.com/sveltejs/sapper/issues/291))
-* Pass `(req, res)` to store getter ([#344](https://github.com/sveltejs/sapper/issues/344))
-
-## 0.15.6
-
-* Fix exporting with custom basepath ([#342](https://github.com/sveltejs/sapper/pull/342))
-
 ## 0.15.5
 
 * Faster `export` with more explanatory output ([#335](https://github.com/sveltejs/sapper/pull/335))

appveyor.yml

@@ -14,7 +14,7 @@ environment:
 
 install:
   - ps: Install-Product node $env:nodejs_version
-  - npm ci
+  - npm install
 
 test_script:
   - node --version && npm --version

mocha.opts

@@ -1,5 +1,4 @@
 --require source-map-support/register
---require ts-node/register
 --recursive
-test/unit/*/*.ts
+test/unit/*/*.js
 test/common/test.js

package.json

@@ -1,6 +1,6 @@
 {
   "name": "sapper",
-  "version": "0.17.0",
+  "version": "0.15.4",
   "description": "Military-grade apps, engineered by Svelte",
   "main": "dist/middleware.ts.js",
   "bin": {
@@ -19,53 +19,50 @@
     "test": "test"
   },
   "dependencies": {
-    "html-minifier": "^3.5.16",
+    "ansi-colors": "^2.0.1",
-    "source-map-support": "^0.5.6",
+    "cheerio": "^1.0.0-rc.2",
-    "tslib": "^1.9.1"
+    "chokidar": "^2.0.3",
-  },
-  "devDependencies": {
-    "@types/glob": "^5.0.34",
-    "@types/mkdirp": "^0.5.2",
-    "@types/mocha": "^5.2.5",
-    "@types/node": "^10.7.1",
-    "@types/rimraf": "^2.0.2",
-    "cheap-watch": "^0.3.0",
-    "compression": "^1.7.1",
     "cookie": "^0.3.1",
     "devalue": "^1.0.4",
-    "eslint": "^4.13.1",
+    "glob": "^7.1.2",
-    "eslint-plugin-import": "^2.12.0",
+    "html-minifier": "^3.5.16",
-    "express": "^4.16.3",
-    "kleur": "^2.0.1",
     "mkdirp": "^0.5.1",
-    "mocha": "^5.2.0",
-    "nightmare": "^3.0.0",
     "node-fetch": "^2.1.1",
-    "npm-run-all": "^4.1.3",
-    "polka": "^0.4.0",
     "port-authority": "^1.0.5",
     "pretty-bytes": "^5.0.0",
     "pretty-ms": "^3.1.0",
     "require-relative": "^0.8.7",
     "rimraf": "^2.6.2",
+    "sade": "^1.4.1",
+    "sander": "^0.6.0",
+    "source-map-support": "^0.5.6",
+    "tslib": "^1.9.1",
+    "url-parse": "^1.2.0",
+    "webpack-format-messages": "^2.0.1"
+  },
+  "devDependencies": {
+    "@types/glob": "^5.0.34",
+    "@types/mkdirp": "^0.5.2",
+    "@types/rimraf": "^2.0.2",
+    "compression": "^1.7.1",
+    "eslint": "^4.13.1",
+    "eslint-plugin-import": "^2.12.0",
+    "express": "^4.16.3",
+    "mocha": "^5.2.0",
+    "nightmare": "^3.0.0",
+    "npm-run-all": "^4.1.3",
+    "polka": "^0.4.0",
     "rollup": "^0.59.2",
     "rollup-plugin-commonjs": "^9.1.3",
     "rollup-plugin-json": "^3.0.0",
-    "rollup-plugin-node-resolve": "^3.3.0",
     "rollup-plugin-string": "^2.0.2",
     "rollup-plugin-typescript": "^0.8.1",
-    "sade": "^1.4.1",
-    "sander": "^0.6.0",
     "serve-static": "^1.13.2",
     "svelte": "^2.6.3",
     "svelte-loader": "^2.9.0",
-    "tiny-glob": "^0.2.2",
-    "ts-node": "^7.0.1",
     "typescript": "^2.8.3",
-    "url-parse": "^1.2.0",
     "walk-sync": "^0.3.2",
-    "webpack": "^4.8.3",
+    "webpack": "^4.8.3"
-    "webpack-format-messages": "^2.0.1"
   },
   "scripts": {
     "cy:open": "cypress open",

rollup.config.js

@@ -1,7 +1,6 @@
 import typescript from 'rollup-plugin-typescript';
 import string from 'rollup-plugin-string';
 import json from 'rollup-plugin-json';
-import resolve from 'rollup-plugin-node-resolve';
 import commonjs from 'rollup-plugin-commonjs';
 import pkg from './package.json';
 
@@ -45,7 +44,6 @@ export default [
 				include: '**/*.md'
 			}),
 			json(),
-			resolve(),
 			commonjs(),
 			typescript({
 				typescript: require('typescript')

src/api/build.ts

@@ -3,7 +3,7 @@ import * as path from 'path';
 import mkdirp from 'mkdirp';
 import rimraf from 'rimraf';
 import { EventEmitter } from 'events';
-import minify_html from './utils/minify_html';
+import { minify_html } from './utils/minify_html';
 import { create_compilers, create_main_manifests, create_routes, create_serviceworker_manifest } from '../core';
 import * as events from './interfaces';
 

src/api/dev.ts

@@ -119,30 +119,21 @@ class Watcher extends EventEmitter {
 		this.dev_server = new DevServer(dev_port);
 
 		this.filewatchers.push(
-			watch_dir(
+			watch_files(locations.routes(), ['add', 'unlink'], () => {
-				locations.routes(),
+				const routes = create_routes();
-				({ path: file, stats }) => {
+				create_main_manifests({ routes, dev_port });
-					if (stats.isDirectory()) {
+
-						return path.basename(file)[0] !== '_';
+				try {
-					}
-					return true;
-				},
-				() => {
 					const routes = create_routes();
 					create_main_manifests({ routes, dev_port });
-
+				} catch (err) {
-					try {
+					this.emit('error', <events.ErrorEvent>{
-						const routes = create_routes();
+						message: err.message
-						create_main_manifests({ routes, dev_port });
+					});
-					} catch (err) {
-						this.emit('error', <events.ErrorEvent>{
-							message: err.message
-						});
-					}
 				}
-			),
+			}),
 
-			fs.watch(`${locations.app()}/template.html`, () => {
+			watch_files(`${locations.app()}/template.html`, ['change'], () => {
 				this.dev_server.send({
 					action: 'reload'
 				});
@@ -233,11 +224,8 @@ class Watcher extends EventEmitter {
 					});
 
 					this.proc.on('message', message => {
-						if (message.__sapper__ && message.event === 'basepath') {
+						if (!message.__sapper__) return;
-							this.emit('basepath', {
+						this.emit(message.event, message);
-								basepath: message.basepath
-							});
-						}
 					});
 
 					this.proc.on('exit', emitFatal);
@@ -462,32 +450,20 @@ class DevServer {
 
 function noop() {}
 
-function watch_dir(
+function watch_files(pattern: string, events: string[], callback: () => void) {
-	dir: string,
+	const chokidar = require('chokidar');
-	filter: ({ path, stats }: { path: string, stats: fs.Stats }) => boolean,
-	callback: () => void
-) {
-	let watch;
-	let closed = false;
 
-	import('cheap-watch').then(CheapWatch => {
+	const watcher = chokidar.watch(pattern, {
-		if (closed) return;
+		persistent: true,
+		ignoreInitial: true,
+		disableGlobbing: true
+	});
 
-		watch = new CheapWatch({ dir, filter, debounce: 50 });
+	events.forEach(event => {
-
+		watcher.on(event, callback);
-		watch.on('+', ({ isNew }) => {
-			if (isNew) callback();
-		});
-
-		watch.on('-', callback);
-
-		watch.init();
 	});
 
 	return {
-		close: () => {
+		close: () => watcher.close()
-			if (watch) watch.close();
-			closed = true;
-		}
 	};
-}
+}

src/api/export.ts

@@ -1,12 +1,12 @@
 import * as child_process from 'child_process';
 import * as path from 'path';
 import * as sander from 'sander';
+import cheerio from 'cheerio';
 import URL from 'url-parse';
 import fetch from 'node-fetch';
 import * as ports from 'port-authority';
 import { EventEmitter } from 'events';
-import clean_html from './utils/clean_html';
+import { minify_html } from './utils/minify_html';
-import minify_html from './utils/minify_html';
 import Deferred from './utils/Deferred';
 import * as events from './interfaces';
 
@@ -51,10 +51,9 @@ async function execute(emitter: EventEmitter, {
 	const port = await ports.find(3000);
 
 	const origin = `http://localhost:${port}`;
-	const root = new URL(basepath || '', origin);
 
 	emitter.emit('info', {
-		message: `Crawling ${root.href}`
+		message: `Crawling ${origin}`
 	});
 
 	const proc = child_process.fork(path.resolve(`${build}/server.js`), [], {
@@ -72,10 +71,8 @@ async function execute(emitter: EventEmitter, {
 	const deferreds = new Map();
 
 	function get_deferred(pathname: string) {
-		pathname = pathname.replace(root.pathname, '');
-
 		if (!deferreds.has(pathname)) {
-			deferreds.set(pathname, new Deferred());
+			deferreds.set(pathname, new Deferred())	;
 		}
 
 		return deferreds.get(pathname);
@@ -110,7 +107,7 @@ async function execute(emitter: EventEmitter, {
 	});
 
 	async function handle(url: URL) {
-		const pathname = (url.pathname.replace(root.pathname, '') || '/');
+		const pathname = url.pathname || '/';
 
 		if (seen.has(pathname)) return;
 		seen.add(pathname);
@@ -123,26 +120,15 @@ async function execute(emitter: EventEmitter, {
 		if (range === 2) {
 			if (r.headers.get('Content-Type') === 'text/html') {
 				const body = await r.text();
+				const $ = cheerio.load(body);
 				const urls: URL[] = [];
 
-				const cleaned = clean_html(body);
+				const base = new URL($('base').attr('href') || '/', url.href);
 
-				const base_match = /<base ([\s\S]+?)>/m.exec(cleaned);
+				$('a[href]').each((i: number, $a) => {
-				const base_href = base_match && get_href(base_match[1]);
+					const url = new URL($a.attribs.href, base.href);
-				const base = new URL(base_href || '/', url.href);
+					if (url.origin === origin) urls.push(url);
-
+				});
-				let match;
-				let pattern = /<a ([\s\S]+?)>/gm;
-
-				while (match = pattern.exec(cleaned)) {
-					const attrs = match[1];
-					const href = get_href(attrs);
-
-					if (href) {
-						const url = new URL(href, base.href);
-						if (url.origin === origin) urls.push(url);
-					}
-				}
 
 				await Promise.all(urls.map(handle));
 			}
@@ -152,14 +138,6 @@ async function execute(emitter: EventEmitter, {
 	}
 
 	return ports.wait(port)
-		.then(() => {
+		.then(() => handle(new URL(`/${basepath}`, origin))) // TODO all static routes
-			// TODO all static routes
-			return handle(root);
-		})
 		.then(() => proc.kill());
 }
-
-function get_href(attrs: string) {
-	const match = /href\s*=\s*(?:"(.+?)"|'(.+?)'|([^\s>]+))/.exec(attrs);
-	return match[1] || match[2] || match[3];
-}

src/api/find_page.ts

@@ -1,3 +1,4 @@
+import * as glob from 'glob';
 import { locations } from '../config';
 import { create_routes } from '../core';
 

src/api/utils/clean_html.ts

@@ -1,7 +0,0 @@
-export default function clean_html(html: string) {
-	return html
-		.replace(/<!\[CDATA\[[\s\S]*?\]\]>/gm, '')
-		.replace(/(<script[\s\S]*?>)[\s\S]*?<\/script>/gm, '$1</' + 'script>')
-		.replace(/(<style[\s\S]*?>)[\s\S]*?<\/style>/gm, '$1</' + 'style>')
-		.replace(/<!--[\s\S]*?-->/gm, '');
-}

src/api/utils/minify_html.ts

@@ -1,6 +1,6 @@
 import { minify } from 'html-minifier';
 
-export default function minify_html(html: string) {
+export function minify_html(html: string) {
 	return minify(html, {
 		collapseBooleanAttributes: true,
 		collapseWhitespace: true,

src/cli.ts

@@ -1,7 +1,7 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import sade from 'sade';
-import colors from 'kleur';
+import * as colors from 'ansi-colors';
 import prettyMs from 'pretty-ms';
 import * as pkg from '../package.json';
 

src/cli/build.ts

@@ -1,5 +1,5 @@
 import { build as _build } from '../api/build';
-import colors from 'kleur';
+import * as colors from 'ansi-colors';
 import { locations } from '../config';
 
 export function build() {

src/cli/dev.ts

@@ -1,7 +1,8 @@
 import * as path from 'path';
-import colors from 'kleur';
+import * as colors from 'ansi-colors';
 import * as child_process from 'child_process';
 import prettyMs from 'pretty-ms';
+import pb from 'pretty-bytes';
 import { dev as _dev } from '../api/dev';
 import * as events from '../api/interfaces';
 
@@ -44,6 +45,32 @@ export function dev(opts: { port: number, open: boolean }) {
 			if (event.log) console.log(event.log);
 		});
 
+		watcher.on('preload', (event) => {
+			if (event.size > 25000) {
+				console.log(colors.bold.yellow(`${event.url} — large amount of preloaded data`));
+				console.log(`${colors.bold(pb(event.size))} of data was preloaded in total, above the recommended limit of ${pb(25000)}`);
+			}
+		});
+
+		watcher.on('unused_data', (event) => {
+			console.log(colors.bold.yellow(`${event.url} — unused preloaded data`));
+			console.log(`More data was returned from \`preload\` than was used during the initial render. Consider only returning essential data.`);
+
+			event.discrepancies.forEach(discrepancy => {
+				console.log(`${colors.bold(discrepancy.file)} loaded ${colors.bold(pb(discrepancy.preloaded))}, of which ${discrepancy.rendered > 2 ? `only ${colors.bold(pb(discrepancy.rendered))}` : 'none'} was used. The following properties were not referenced:`);
+
+				const slice = discrepancy.props.length > 12
+					? discrepancy.props.slice(0, 10)
+					: discrepancy.props;
+
+				console.log(slice.map((prop: string) => `• ${prop}`).join('\n'));
+
+				if (discrepancy.props.length > slice.length) {
+					console.log(`...and ${discrepancy.props.length - slice.length} more`);
+				}
+			});
+		});
+
 		watcher.on('build', (event: events.BuildEvent) => {
 			if (event.errors.length) {
 				console.log(`${colors.bold.red(`✗ ${event.type}`)}`);

src/cli/export.ts

@@ -1,5 +1,5 @@
 import { exporter as _exporter } from '../api/export';
-import colors from 'kleur';
+import * as colors from 'ansi-colors';
 import prettyBytes from 'pretty-bytes';
 import { locations } from '../config';
 

src/cli/start.ts

@@ -1,7 +1,7 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import * as child_process from 'child_process';
-import colors from 'kleur';
+import * as colors from 'ansi-colors';
 import * as ports from 'port-authority';
 
 export async function start(dir: string, opts: { port: number, open: boolean }) {

src/cli/upgrade.ts

@@ -1,5 +1,5 @@
 import * as fs from 'fs';
-import colors from 'kleur';
+import * as colors from 'ansi-colors';
 
 export default async function upgrade() {
 	const upgraded = [

src/core/create_manifests.ts

@@ -1,6 +1,6 @@
 import * as fs from 'fs';
 import * as path from 'path';
-import glob from 'tiny-glob/sync.js';
+import * as glob from 'glob';
 import { posixify, write_if_changed } from './utils';
 import { dev, locations } from '../config';
 import { Page, PageComponent, ServerRoute } from '../interfaces';
@@ -9,27 +9,24 @@ export function create_main_manifests({ routes, dev_port }: {
 	routes: { components: PageComponent[], pages: Page[], server_routes: ServerRoute[] };
 	dev_port?: number;
 }) {
-	const manifest_dir = path.join(locations.app(), 'manifest');
+	const path_to_routes = path.relative(`${locations.app()}/manifest`, locations.routes());
-	if (!fs.existsSync(manifest_dir)) fs.mkdirSync(manifest_dir);
-
-	const path_to_routes = path.relative(manifest_dir, locations.routes());
 
 	const client_manifest = generate_client(routes, path_to_routes, dev_port);
 	const server_manifest = generate_server(routes, path_to_routes);
 
 	write_if_changed(
-		`${manifest_dir}/default-layout.html`,
+		`${locations.app()}/manifest/default-layout.html`,
 		`<svelte:component this={child.component} {...child.props}/>`
 	);
-	write_if_changed(`${manifest_dir}/client.js`, client_manifest);
+	write_if_changed(`${locations.app()}/manifest/client.js`, client_manifest);
-	write_if_changed(`${manifest_dir}/server.js`, server_manifest);
+	write_if_changed(`${locations.app()}/manifest/server.js`, server_manifest);
 }
 
 export function create_serviceworker_manifest({ routes, client_files }: {
 	routes: { components: PageComponent[], pages: Page[], server_routes: ServerRoute[] };
 	client_files: string[];
 }) {
-	const assets = glob('**', { cwd: 'assets', filesOnly: true });
+	const assets = glob.sync('**', { cwd: 'assets', nodir: true });
 
 	let code = `
 		// This file is generated by Sapper — do not edit it!
@@ -45,6 +42,11 @@ export function create_serviceworker_manifest({ routes, client_files }: {
 	write_if_changed(`${locations.app()}/manifest/service-worker.js`, code);
 }
 
+function right_pad(str: string, len: number) {
+	while (str.length < len) str += ' ';
+	return str;
+}
+
 function generate_client(
 	routes: { root: PageComponent, components: PageComponent[], pages: Page[], server_routes: ServerRoute[] },
 	path_to_routes: string,
@@ -154,6 +156,7 @@ function generate_server(
 
 							const props = [
 								`name: "${part.component.name}"`,
+								`file: "${part.component.file}"`,
 								`component: ${part.component.name}`
 							];
 

src/core/create_routes.ts

@@ -4,6 +4,11 @@ import { locations } from '../config';
 import { Page, PageComponent, ServerRoute } from '../interfaces';
 import { posixify } from './utils';
 
+const default_layout_file = posixify(path.resolve(
+	__dirname,
+	'../components/default-layout.html'
+));
+
 export default function create_routes(cwd = locations.routes()) {
 	const components: PageComponent[] = [];
 	const pages: Page[] = [];

src/core/utils.ts

@@ -1,11 +1,11 @@
-import * as fs from 'fs';
+import * as sander from 'sander';
 
 const previous_contents = new Map();
 
 export function write_if_changed(file: string, code: string) {
 	if (code !== previous_contents.get(file)) {
 		previous_contents.set(file, code);
-		fs.writeFileSync(file, code);
+		sander.writeFileSync(file, code);
 		fudge_mtime(file);
 	}
 }
@@ -16,8 +16,8 @@ export function posixify(file: string) {
 
 export function fudge_mtime(file: string) {
 	// need to fudge the mtime so that webpack doesn't go doolally
-	const { atime, mtime } = fs.statSync(file);
+	const { atime, mtime } = sander.statSync(file);
-	fs.utimesSync(
+	sander.utimesSync(
 		file,
 		new Date(atime.getTime() - 999999),
 		new Date(mtime.getTime() - 999999)

src/middleware.ts

@@ -8,6 +8,9 @@ import fetch from 'node-fetch';
 import { lookup } from './middleware/mime';
 import { locations, dev } from './config';
 import sourceMapSupport from 'source-map-support';
+import prettyBytes from 'pretty-bytes';
+import { wrap_data } from './middleware/wrap_data';
+import { list_unused_properties } from './middleware/list_unused_properties';
 
 sourceMapSupport.install();
 
@@ -83,7 +86,7 @@ function toIgnore(uri: string, val: any) {
 
 export default function middleware(opts: {
 	manifest: Manifest,
-	store: (req: Req, res: ServerResponse) => Store,
+	store: (req: Req) => Store,
 	ignore?: any,
 	routes?: any // legacy
 }) {
@@ -276,10 +279,7 @@ function get_server_route_handler(routes: ServerRoute[]) {
 	};
 }
 
-function get_page_handler(
+function get_page_handler(manifest: Manifest, store_getter: (req: Req) => Store) {
-	manifest: Manifest,
-	store_getter: (req: Req, res: ServerResponse) => Store
-) {
 	const output = locations.dest();
 
 	const get_chunks = dev()
@@ -293,16 +293,21 @@ function get_page_handler(
 	const { server_routes, pages } = manifest;
 	const error_route = manifest.error;
 
+	const should_wrap_data = dev() || process.env.SAPPER_EXPORT;
+
 	function handle_error(req: Req, res: ServerResponse, statusCode: number, error: Error | string) {
 		handle_page({
 			pattern: null,
 			parts: [
 				{ name: null, component: error_route }
 			]
-		}, req, res, statusCode, error || new Error('Unknown error in preload function'));
+		}, req, res, statusCode, error);
 	}
 
 	function handle_page(page: Page, req: Req, res: ServerResponse, status = 200, error: Error | string = null) {
+		const get_params = page.parts[page.parts.length - 1].params || (() => ({}));
+		const match = error ? null : page.pattern.exec(req.path);
+
 		const chunks: Record<string, string | string[]> = get_chunks();
 
 		res.setHeader('Content-Type', 'text/html');
@@ -326,7 +331,7 @@ function get_page_handler(
 
 		res.setHeader('Link', link);
 
-		const store = store_getter ? store_getter(req, res) : null;
+		const store = store_getter ? store_getter(req) : null;
 
 		let redirect: { statusCode: number, location: string };
 		let preload_error: { statusCode: number, message: Error | string };
@@ -336,7 +341,6 @@ function get_page_handler(
 				if (redirect && (redirect.statusCode !== statusCode || redirect.location !== location)) {
 					throw new Error(`Conflicting redirects`);
 				}
-				location = location.replace(/^\//g, ''); // leading slash (only)
 				redirect = { statusCode, location };
 			},
 			error: (statusCode: number, message: Error | string) => {
@@ -388,8 +392,6 @@ function get_page_handler(
 			})
 			: {};
 
-		const match = error ? null : page.pattern.exec(req.path);
-
 		Promise.all([root_preloaded].concat(page.parts.map(part => {
 			if (!part) return null;
 
@@ -431,11 +433,6 @@ function get_page_handler(
 				return;
 			}
 
-			const serialized = {
-				preloaded: `[${preloaded.map(data => try_serialize(data)).join(',')}]`,
-				store: store && try_serialize(store.get())
-			};
-
 			const segments = req.path.split('/').filter(Boolean);
 
 			const props: Props = {
@@ -457,6 +454,15 @@ function get_page_handler(
 				}
 			});
 
+			// in dev and export modes, we wrap data in proxies to see
+			// how much of it is used in the initial render
+			const wrapped = should_wrap_data && wrap_data(preloaded);
+
+			// this is an easy way to 'reify' top-level values
+			const _preloaded = should_wrap_data
+				? wrapped.data.map((x: any) => x)
+				: preloaded;
+
 			let level = data.child;
 			for (let i = 0; i < page.parts.length; i += 1) {
 				const part = page.parts[i];
@@ -468,7 +474,7 @@ function get_page_handler(
 					component: part.component,
 					props: Object.assign({}, props, {
 						params: get_params(match)
-					}, preloaded[i + 1])
+					}, _preloaded[i + 1])
 				});
 
 				level.props.child = <Props["child"]>{
@@ -487,6 +493,47 @@ function get_page_handler(
 				.map(file => `<script src='${req.baseUrl}/client/${file}'></script>`)
 				.join('');
 
+			const unwrapped = should_wrap_data && wrapped.unwrap();
+
+			const preloaded_serialized = preloaded.map(try_serialize);
+
+			if (should_wrap_data && process.send) {
+				const discrepancies = [];
+
+				unwrapped.forEach((clone, i) => {
+					const loaded = preloaded_serialized[i];
+					if (!loaded) return;
+
+					const rendered = try_serialize(clone);
+
+					if (rendered !== loaded) {
+						const part = page.parts[i - 1];
+						const file = part ? part.file : '_layout.html';
+
+						discrepancies.push({
+							file,
+							preloaded: loaded.length,
+							rendered: rendered.length,
+							props: list_unused_properties(preloaded[i], clone)
+						});
+					}
+				});
+
+				if (discrepancies.length) {
+					process.send({
+						__sapper__: true,
+						event: 'unused_data',
+						url: req.url,
+						discrepancies
+					});
+				}
+			}
+
+			const serialized = {
+				preloaded: `[${preloaded_serialized.join(',')}]`,
+				store: store && try_serialize(store.get())
+			};
+
 			let inline_script = `__SAPPER__={${[
 				error && `error:1`,
 				`baseUrl:"${req.baseUrl}"`,
@@ -510,6 +557,13 @@ function get_page_handler(
 			res.end(body);
 
 			if (process.send) {
+				process.send({
+					__sapper__: true,
+					event: 'preload',
+					url: req.url,
+					size: serialized.preloaded.length
+				});
+
 				process.send({
 					__sapper__: true,
 					event: 'file',
@@ -585,4 +639,4 @@ function escape_html(html: string) {
 	};
 
 	return html.replace(/["'&<>]/g, c => `&${chars[c]};`);
-}
+}

src/middleware/list_unused_properties.ts

@@ -0,0 +1,34 @@
+export function list_unused_properties(all: any, used: any) {
+	const props: string[] = [];
+
+	const seen = new Set();
+
+	function walk(keypath: string, a: any, b: any) {
+		if (seen.has(a)) return;
+		seen.add(a);
+
+		if (!a || typeof a !== 'object') return;
+
+		const is_array = Array.isArray(a);
+
+		for (const key in a) {
+			const child_keypath = keypath
+				? is_array ? `${keypath}[${key}]` : `${keypath}.${key}`
+				: key;
+
+			if (hasProp.call(b, key)) {
+				const a_child = a[key];
+				const b_child = b[key];
+
+				walk(child_keypath, a_child, b_child);
+			} else {
+				props.push(child_keypath);
+			}
+		}
+	}
+
+	walk(null, all, used);
+	return props;
+}
+
+const hasProp = Object.prototype.hasOwnProperty;

src/middleware/wrap_data.ts

@@ -0,0 +1,85 @@
+type Obj = Record<string, any>;
+
+export function wrap_data(data: any) {
+	const proxies = new Map();
+	const clones = new Map();
+
+	const handler = {
+		get(target: any, property: string): any {
+			const value = target[property];
+			const intercepted = intercept(value);
+
+			const target_clone = clones.get(target);
+			const child_clone = clones.get(value);
+
+			if (target_clone && target.hasOwnProperty(property)) {
+				target_clone[property] = child_clone || value;
+			}
+
+			return intercepted;
+		},
+	};
+
+	function get_or_create_proxy(obj: any) {
+		if (!proxies.has(obj)) {
+			proxies.set(obj, new Proxy(obj, handler));
+		}
+
+		return proxies.get(obj);
+	}
+
+	function intercept(obj: any) {
+		if (clones.has(obj)) return obj;
+
+		if (obj && typeof obj === 'object') {
+			if (Array.isArray(obj)) {
+				clones.set(obj, []);
+				return get_or_create_proxy(obj);
+			}
+
+			else if (isPlainObject(obj)) {
+				clones.set(obj, {});
+				return get_or_create_proxy(obj);
+			}
+		}
+
+		clones.set(obj, obj);
+		return obj;
+	}
+
+	return {
+		data: intercept(data),
+		unwrap: () => {
+			return clones.get(data);
+		}
+	};
+}
+
+const objectProtoOwnPropertyNames = Object.getOwnPropertyNames(Object.prototype).sort().join('\0')
+
+function isPlainObject(obj: any) {
+	const proto = Object.getPrototypeOf(obj);
+
+	if (
+		proto !== Object.prototype &&
+		proto !== null &&
+		Object.getOwnPropertyNames(proto).sort().join('\0') !== objectProtoOwnPropertyNames
+	) {
+		return false;
+	}
+
+	if (Object.getOwnPropertySymbols(obj).length > 0) {
+		return false;
+	}
+
+	return true;
+}
+
+
+function pick(obj: Obj, props: string[]) {
+	const picked: Obj = {};
+	props.forEach(prop => {
+		picked[prop] = obj[prop];
+	});
+	return picked;
+}

src/runtime/index.ts

@@ -136,6 +136,10 @@ function prepare_page(target: Target): Promise<{
 	data?: any;
 	nullable_depth?: number;
 }> {
+	if (root) {
+		root.set({ preloading: true });
+	}
+
 	const { page, path, query } = target;
 	const new_segments = path.split('/').filter(Boolean);
 	let changed_from = 0;
@@ -281,9 +285,6 @@ async function navigate(target: Target, id: number): Promise<any> {
 
 	cid = id;
 
-	if (root) {
-		root.set({ preloading: true });
-	}
 	const loaded = prefetching && prefetching.href === target.url.href ?
 		prefetching.promise :
 		prepare_page(target);

test/app/app/server.js

@@ -85,18 +85,11 @@ const middlewares = [
 		next();
 	},
 
-	// set up some values for the store
-	(req, res, next) => {
-		req.hello = 'hello';
-		res.locals = { name: 'world' };
-		next();
-	},
-
 	sapper({
 		manifest,
-		store: (req, res) => {
+		store: () => {
 			return new Store({
-				title: `${req.hello} ${res.locals.name}`
+				title: 'Stored title'
 			});
 		},
 		ignore: [

test/app/routes/index.html

@@ -8,7 +8,6 @@
 <a href='about'>about</a>
 <a href='slow-preload'>slow preload</a>
 <a href='redirect-from'>redirect</a>
-<a href='redirect-root'>redirect (root)</a>
 <a href='blog/nope'>broken link</a>
 <a href='blog/throw-an-error'>error link</a>
 <a href='credentials?creds=include'>credentials</a>

test/app/routes/redirect-root.html

@@ -1,7 +0,0 @@
-<script>
-	export default {
-		preload() {
-			this.redirect(301, '/');
-		}
-	};
-</script>

test/common/test.js

@@ -59,19 +59,9 @@ describe('sapper', function() {
 		basepath: '/custom-basepath'
 	});
 
-	testExport({});
+	describe('export', () => {
-
-	testExport({ basepath: '/custom-basepath' });
-});
-
-function testExport({ basepath = '' }) {
-	describe(basepath ? `export --basepath ${basepath}` : 'export', () => {
 		before(() => {
-			if (basepath) {
+			return exec(`node ${cli} export`);
-				process.env.BASEPATH = basepath;
-			}
-
-			return exec(`node ${cli} export ${basepath ? `--basepath ${basepath}` : ''}`);
 		});
 
 		it('export all pages', () => {
@@ -106,10 +96,7 @@ function testExport({ basepath = '' }) {
 				'service-worker.js',
 				'svelte-logo-192.png',
 				'svelte-logo-512.png',
-			].map(file => {
+			];
-				return basepath ? `${basepath.replace(/^[\/\\]/, '')}/${file}` : file;
-			});
-
 			// Client scripts that should show up in the extraction directory.
 			const expectedClientRegexes = [
 				/client\/[^/]+\/main(\.\d+)?\.js/,
@@ -139,7 +126,7 @@ function testExport({ basepath = '' }) {
 			});
 		});
 	});
-}
+});
 
 function run({ mode, basepath = '' }) {
 	describe(`mode=${mode}`, function () {
@@ -436,33 +423,6 @@ function run({ mode, basepath = '' }) {
 					});
 			});
 
-			it('redirects on server (root)', () => {
-				return nightmare.goto(`${base}/redirect-root`)
-					.path()
-					.then(path => {
-						assert.equal(path, `${basepath}/`);
-					})
-					.then(() => nightmare.page.title())
-					.then(title => {
-						assert.equal(title, 'Great success!');
-					});
-			});
-
-			it('redirects in client (root)', () => {
-				return nightmare.goto(base)
-					.wait('[href="redirect-root"]')
-					.click('[href="redirect-root"]')
-					.wait(200)
-					.path()
-					.then(path => {
-						assert.equal(path, `${basepath}/`);
-					})
-					.then(() => nightmare.page.title())
-					.then(title => {
-						assert.equal(title, 'Great success!');
-					});
-			});
-
 			it('handles 4xx error on server', () => {
 				return nightmare.goto(`${base}/blog/nope`)
 					.path()
@@ -608,11 +568,11 @@ function run({ mode, basepath = '' }) {
 				return nightmare.goto(`${base}/store`)
 					.page.title()
 					.then(title => {
-						assert.equal(title, 'hello world');
+						assert.equal(title, 'Stored title');
 						return nightmare.init().page.title();
 					})
 					.then(title => {
-						assert.equal(title, 'hello world');
+						assert.equal(title, 'Stored title');
 					});
 			});
 

test/unit/clean_html/index.ts

@@ -1,26 +0,0 @@
-import * as fs from 'fs';
-import * as path from 'path';
-import * as assert from 'assert';
-import clean_html from '../../../src/api/utils/clean_html';
-
-describe('clean_html', () => {
-	const samples = path.join(__dirname, 'samples');
-
-	fs.readdirSync(samples).forEach(dir => {
-		if (dir[0] === '.') return;
-
-		it(dir, () => {
-			const input = fs.readFileSync(`${samples}/${dir}/input.html`, 'utf-8');
-			const expected = fs.readFileSync(`${samples}/${dir}/output.html`, 'utf-8');
-
-			const actual = clean_html(input);
-
-			fs.writeFileSync(`${samples}/${dir}/.actual.html`, actual);
-
-			assert.equal(
-				actual.replace(/\s+$/gm, ''),
-				expected.replace(/\s+$/gm, '')
-			);
-		});
-	});
-});

test/unit/clean_html/samples/removes-cdata/.actual.html

@@ -1,14 +0,0 @@
-<!doctype html>
-<html lang="en">
-<head>
-</head>
-<body>
-	<math>
-		<ms></ms>
-		<mo>+</mo>
-		<mn>3</mn>
-		<mo>=</mo>
-		<ms></ms>
-	</math>
-</body>
-</html>

test/unit/clean_html/samples/removes-cdata/input.html

@@ -1,14 +0,0 @@
-<!doctype html>
-<html lang="en">
-<head>
-</head>
-<body>
-	<math>
-		<ms><![CDATA[x<y]]></ms>
-		<mo>+</mo>
-		<mn>3</mn>
-		<mo>=</mo>
-		<ms><![CDATA[x<y3]]></ms>
-	</math>
-</body>
-</html>

test/unit/clean_html/samples/removes-cdata/output.html

@@ -1,14 +0,0 @@
-<!doctype html>
-<html lang="en">
-<head>
-</head>
-<body>
-	<math>
-		<ms></ms>
-		<mo>+</mo>
-		<mn>3</mn>
-		<mo>=</mo>
-		<ms></ms>
-	</math>
-</body>
-</html>

test/unit/clean_html/samples/removes-comments/.actual.html

@@ -1,9 +0,0 @@
-<!doctype html>
-<html lang="en">
-<head>
-</head>
-<body>
-	<a href="keep-me">keep me</a>
-	
-</body>
-</html>

test/unit/clean_html/samples/removes-comments/input.html

@@ -1,9 +0,0 @@
-<!doctype html>
-<html lang="en">
-<head>
-</head>
-<body>
-	<a href="keep-me">keep me</a>
-	<!-- <a href="delete-me">delete me</a> -->
-</body>
-</html>

test/unit/clean_html/samples/removes-comments/output.html

@@ -1,9 +0,0 @@
-<!doctype html>
-<html lang="en">
-<head>
-</head>
-<body>
-	<a href="keep-me">keep me</a>
-
-</body>
-</html>

test/unit/clean_html/samples/removes-script-contents/.actual.html

@@ -1,12 +0,0 @@
-<!doctype html>
-<html lang="en">
-<head>
-</head>
-<body>
-	<script></script>
-
-	<script></script>
-
-	<script src="attributes-are-preserved.js"></script>
-</body>
-</html>

test/unit/clean_html/samples/removes-script-contents/input.html

@@ -1,16 +0,0 @@
-<!doctype html>
-<html lang="en">
-<head>
-</head>
-<body>
-	<script>
-		console.log('this should be deleted');
-	</script>
-
-	<script>
-		console.log('so should this');
-	</script>
-
-	<script src="attributes-are-preserved.js"></script>
-</body>
-</html>

test/unit/clean_html/samples/removes-script-contents/output.html

@@ -1,12 +0,0 @@
-<!doctype html>
-<html lang="en">
-<head>
-</head>
-<body>
-	<script></script>
-
-	<script></script>
-
-	<script src="attributes-are-preserved.js"></script>
-</body>
-</html>

test/unit/create_routes/index.js

@@ -1,6 +1,6 @@
-import * as path from 'path';
+const path = require('path');
-import * as assert from 'assert';
+const assert = require('assert');
-import create_routes from '../../../src/core/create_routes';
+const { create_routes } = require('../../../dist/core.ts.js');
 
 describe('create_routes', () => {
 	it('creates routes', () => {