From 99853c51811d5aff780d7df2e16c94b5124b6d75 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Sat, 3 Mar 2018 21:48:50 -0500
Subject: [PATCH] various stability improvements

---
 package.json                          |   2 +-
 hmr-client.js => sapper-dev-client.js |  16 ++-
 src/cli/dev.ts                        |  10 +-
 src/core/create_app.ts                |   6 +-
 src/core/create_template.ts           |  39 --------
 src/core/index.ts                     |   3 +-
 src/middleware/index.ts               | 137 +++++++++++++++-----------
 7 files changed, 102 insertions(+), 111 deletions(-)
 rename hmr-client.js => sapper-dev-client.js (56%)
 delete mode 100644 src/core/create_template.ts

diff --git a/package.json b/package.json
index 93233aa..a0d6210 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,7 @@
     "middleware.js",
     "runtime",
     "runtime.js",
-    "hmr-client.js",
+    "sapper-dev-client.js",
     "webpack"
   ],
   "directories": {
diff --git a/hmr-client.js b/sapper-dev-client.js
similarity index 56%
rename from hmr-client.js
rename to sapper-dev-client.js
index 88938dc..d1b59e1 100644
--- a/hmr-client.js
+++ b/sapper-dev-client.js
@@ -3,7 +3,7 @@ let source;
 function check() {
 	if (module.hot.status() === 'idle') {
 		module.hot.check(true).then(modules => {
-			console.log(`HMR updated`);
+			console.log(`[SAPPER] applied HMR update`);
 		});
 	}
 }
@@ -11,16 +11,26 @@ function check() {
 export function connect(port) {
 	if (source || !window.EventSource) return;
 
-	source = new EventSource(`http://localhost:${port}/hmr`);
+	source = new EventSource(`http://localhost:${port}/__sapper__`);
+
+	window.source = source;
 
 	source.onopen = function(event) {
-		console.log(`HMR connected`);
+		console.log(`[SAPPER] dev client connected`);
+	};
+
+	source.onerror = function(error) {
+		console.error(error);
 	};
 
 	source.onmessage = function(event) {
 		const data = JSON.parse(event.data);
 		if (!data) return; // just a heartbeat
 
+		if (data.action === 'reload') {
+			window.location.reload();
+		}
+
 		if (data.status === 'completed') {
 			check();
 		}
diff --git a/src/cli/dev.ts b/src/cli/dev.ts
index 421f1bd..0cc7798 100644
--- a/src/cli/dev.ts
+++ b/src/cli/dev.ts
@@ -8,7 +8,7 @@ import mkdirp from 'mkdirp';
 import rimraf from 'rimraf';
 import { wait_for_port } from './utils';
 import { dest } from '../config';
-import { create_compilers, create_app, create_routes, create_serviceworker, create_template } from 'sapper/core.js';
+import { create_compilers, create_app, create_routes, create_serviceworker } from 'sapper/core.js';
 
 type Deferred = {
 	promise?: Promise<any>;
@@ -31,11 +31,12 @@ function create_hot_update_server(port: number, interval = 10000) {
 	const clients = new Set();
 
 	const server = http.createServer((req, res) => {
-		if (req.url !== '/hmr') return;
+		if (req.url !== '/__sapper__') return;
 
 		req.socket.setKeepAlive(true);
 		res.writeHead(200, {
 			'Access-Control-Allow-Origin': '*',
+			'Access-Control-Allow-Headers': 'Cache-Control',
 			'Content-Type': 'text/event-stream;charset=utf-8',
 			'Cache-Control': 'no-cache, no-transform',
 			'Connection': 'keep-alive',
@@ -103,8 +104,9 @@ export default async function dev() {
 	});
 
 	watch_files('app/template.html', ['change'], () => {
-		const template = create_template();
-		// TODO reload current page?
+		hot_update_server.send({
+			action: 'reload'
+		});
 	});
 
 	let proc: child_process.ChildProcess;
diff --git a/src/core/create_app.ts b/src/core/create_app.ts
index 79165ff..42eccce 100644
--- a/src/core/create_app.ts
+++ b/src/core/create_app.ts
@@ -56,14 +56,14 @@ function generate_client(routes: Route[], dev_port?: number) {
 		];`.replace(/^\t\t/gm, '').trim();
 
 	if (dev()) {
-		const hmr_client = posixify(
-			path.resolve(__dirname, 'hmr-client.js')
+		const sapper_dev_client = posixify(
+			path.resolve(__dirname, 'sapper-dev-client.js')
 		);
 
 		code += `
 
 			if (module.hot) {
-				import('${hmr_client}').then(client => {
+				import('${sapper_dev_client}').then(client => {
 					client.connect(${dev_port});
 				});
 			}`.replace(/^\t{3}/gm, '');
diff --git a/src/core/create_template.ts b/src/core/create_template.ts
deleted file mode 100644
index 3ca5da9..0000000
--- a/src/core/create_template.ts
+++ /dev/null
@@ -1,39 +0,0 @@
-import * as fs from 'fs';
-import chalk from 'chalk';
-import framer from 'code-frame';
-import { locate } from 'locate-character';
-
-function error(e: any) {
-	if (e.title) console.error(chalk.bold.red(e.title));
-	if (e.body) console.error(chalk.red(e.body));
-	if (e.url) console.error(chalk.cyan(e.url));
-	if (e.frame) console.error(chalk.grey(e.frame));
-
-	process.exit(1);
-}
-
-export default function create_templates() {
-	const template = fs.readFileSync(`app/template.html`, 'utf-8');
-
-	const index = template.indexOf('%sapper.main%');
-	if (index !== -1) {
-		// TODO remove this in a future version
-		const { line, column } = locate(template, index, { offsetLine: 1 });
-		const frame = framer(template, line, column);
-
-		error({
-			title: `app/template.html`,
-			body: `<script src='%sapper.main%'> is unsupported — use %sapper.scripts% (without the <script> tag) instead`,
-			url: 'https://github.com/sveltejs/sapper/issues/86',
-			frame
-		});
-	}
-
-	return {
-		render: (data: Record<string, string>) => {
-			return template.replace(/%sapper\.(\w+)%/g, (match, key) => {
-				return key in data ? data[key] : '';
-			});
-		}
-	};
-}
\ No newline at end of file
diff --git a/src/core/index.ts b/src/core/index.ts
index f6bc4e2..80b7812 100644
--- a/src/core/index.ts
+++ b/src/core/index.ts
@@ -1,5 +1,4 @@
 export { default as create_app } from './create_app';
 export { default as create_serviceworker } from './create_serviceworker';
 export { default as create_compilers } from './create_compilers';
-export { default as create_routes } from './create_routes';
-export { default as create_template } from './create_template';
\ No newline at end of file
+export { default as create_routes } from './create_routes';
\ No newline at end of file
diff --git a/src/middleware/index.ts b/src/middleware/index.ts
index 5d44c1a..832653a 100644
--- a/src/middleware/index.ts
+++ b/src/middleware/index.ts
@@ -1,13 +1,13 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import { ClientRequest, ServerResponse } from 'http';
-// import * as mime from 'mime';
+import * as mime from 'mime';
 import mkdirp from 'mkdirp';
 import rimraf from 'rimraf';
 import serialize from 'serialize-javascript';
 import escape_html from 'escape-html';
-import { create_routes, templates, create_compilers, create_template } from 'sapper/core.js';
-import { dest } from '../config';
+import { create_routes, templates, create_compilers } from 'sapper/core.js';
+import { dest, dev } from '../config';
 import { Route, Template } from '../interfaces';
 import sourceMapSupport from 'source-map-support';
 
@@ -45,58 +45,70 @@ export default function middleware({ routes }: {
 
 	const client_info = JSON.parse(fs.readFileSync(path.join(output, 'client_info.json'), 'utf-8'));
 
-	const template = create_template();
-
-	const shell = try_read(path.join(output, 'index.html'));
-	const serviceworker = try_read(path.join(output, 'service-worker.js'));
-
 	const middleware = compose_handlers([
 		(req: Req, res: ServerResponse, next: () => void) => {
 			req.pathname = req.url.replace(/\?.*/, '');
 			next();
 		},
 
-		shell && get_asset_handler({
+		exists(path.join(output, 'index.html')) && serve({
 			pathname: '/index.html',
-			type: 'text/html',
-			cache: 'max-age=600',
-			body: shell
+			cache_control: 'max-age=600'
 		}),
 
-		serviceworker && get_asset_handler({
+		exists(path.join(output, 'service-worker.js')) && serve({
 			pathname: '/service-worker.js',
-			type: 'application/javascript',
-			cache: 'max-age=600',
-			body: serviceworker
+			cache_control: 'max-age=600'
 		}),
 
-		(req: Req, res: ServerResponse, next: () => void) => {
-			if (req.pathname.startsWith('/client/')) {
-				// const type = mime.getType(req.pathname);
-				const type = 'application/javascript'; // TODO might not be, if using e.g. CSS plugin
+		serve({
+			prefix: '/client/',
+			cache_control: 'max-age=31536000'
+		}),
 
-				// TODO cache?
-				const rs = fs.createReadStream(path.join(output, req.pathname.slice(1)));
-
-				rs.on('error', error => {
-					res.statusCode = 404;
-					res.end('not found');
-				});
-
-				res.setHeader('Content-Type', type);
-				res.setHeader('Cache-Control', 'max-age=31536000');
-				rs.pipe(res);
-			} else {
-				next();
-			}
-		},
-
-		get_route_handler(client_info.assetsByChunkName, routes, template)
+		get_route_handler(client_info.assetsByChunkName, routes)
 	].filter(Boolean));
 
 	return middleware;
 }
 
+function serve({ prefix, pathname, cache_control }: {
+	prefix?: string,
+	pathname?: string,
+	cache_control: string
+}) {
+	const filter = pathname
+		? (req: Req) => req.pathname === pathname
+		: (req: Req) => req.pathname.startsWith(prefix);
+
+	const output = dest();
+
+	const cache: Map<string, Buffer> = new Map();
+
+	const read = dev()
+		? (file: string) => fs.readFileSync(path.resolve(output, file))
+		: (file: string) => (cache.has(file) ? cache : cache.set(file, fs.readFileSync(path.resolve(output, file)))).get(file)
+
+	return (req: Req, res: ServerResponse, next: () => void) => {
+		if (filter(req)) {
+			const type = mime.getType(req.pathname);
+
+			try {
+				const data = read(req.pathname.slice(1));
+
+				res.setHeader('Content-Type', type);
+				res.setHeader('Cache-Control', cache_control);
+				res.end(data);
+			} catch (err) {
+				res.statusCode = 404;
+				res.end('not found');
+			}
+		} else {
+			next();
+		}
+	};
+}
+
 function get_asset_handler({ pathname, type, cache, body }: {
 	pathname: string;
 	type: string;
@@ -114,7 +126,11 @@ function get_asset_handler({ pathname, type, cache, body }: {
 
 const resolved = Promise.resolve();
 
-function get_route_handler(chunks: Record<string, string>, routes: RouteObject[], template: Template) {
+function get_route_handler(chunks: Record<string, string>, routes: RouteObject[]) {
+	const template = dev()
+		? () => fs.readFileSync('app/template.html', 'utf-8')
+		: (str => () => str)(fs.readFileSync('app/template.html', 'utf-8'));
+
 	function handle_route(route: RouteObject, req: Req, res: ServerResponse) {
 		req.params = route.params(route.pattern.exec(req.pathname));
 
@@ -174,12 +190,11 @@ function get_route_handler(chunks: Record<string, string>, routes: RouteObject[]
 
 				scripts = `<script>__SAPPER__ = { preloaded: ${serialized} };</script>${scripts}`;
 
-				const page = template.render({
-					scripts,
-					html,
-					head: `<noscript id='sapper-head-start'></noscript>${head}<noscript id='sapper-head-end'></noscript>`,
-					styles: (css && css.code ? `<style>${css.code}</style>` : '')
-				});
+				const page = template()
+					.replace('%sapper.scripts%', scripts)
+					.replace('%sapper.html%', html)
+					.replace('%sapper.head%', `<noscript id='sapper-head-start'></noscript>${head}<noscript id='sapper-head-end'></noscript>`)
+					.replace('%sapper.styles%', (css && css.code ? `<style>${css.code}</style>` : ''));
 
 				res.end(page);
 
@@ -271,17 +286,19 @@ function get_route_handler(chunks: Record<string, string>, routes: RouteObject[]
 
 		const { head, css, html } = rendered;
 
-		res.end(template.render({
-			scripts: `<script src='/client/${chunks.main}'></script>`,
-			html,
-			head: `<noscript id='sapper-head-start'></noscript>${head}<noscript id='sapper-head-end'></noscript>`,
-			styles: (css && css.code ? `<style>${css.code}</style>` : '')
-		}));
+		const page = template()
+			.replace('%sapper.scripts%', `<script src='/client/${chunks.main}'></script>`)
+			.replace('%sapper.html%', html)
+			.replace('%sapper.head%', `<noscript id='sapper-head-start'></noscript>${head}<noscript id='sapper-head-end'></noscript>`)
+			.replace('%sapper.styles%', (css && css.code ? `<style>${css.code}</style>` : ''));
+
+		res.end(page);
 	}
 
 	const error_route = routes.find((route: RouteObject) => route.error === '5xx');
 
 	function handle_error(req: Req, res: ServerResponse, statusCode: number, message: Error | string) {
+		// TODO lot of repetition between this and handle_not_found
 		if (statusCode >= 400 && statusCode < 500) {
 			return handle_not_found(req, res, statusCode, message);
 		}
@@ -298,12 +315,13 @@ function get_route_handler(chunks: Record<string, string>, routes: RouteObject[]
 
 		const { head, css, html } = rendered;
 
-		res.end(template.render({
-			scripts: `<script src='/client/${chunks.main}'></script>`,
-			html,
-			head: `<noscript id='sapper-head-start'></noscript>${head}<noscript id='sapper-head-end'></noscript>`,
-			styles: (css && css.code ? `<style>${css.code}</style>` : '')
-		}));
+		const page = template()
+			.replace('%sapper.scripts%', `<script src='/client/${chunks.main}'></script>`)
+			.replace('%sapper.html%', html)
+			.replace('%sapper.head%', `<noscript id='sapper-head-start'></noscript>${head}<noscript id='sapper-head-end'></noscript>`)
+			.replace('%sapper.styles%', (css && css.code ? `<style>${css.code}</style>` : ''));
+
+		res.end(page);
 	}
 
 	return function find_route(req: Req, res: ServerResponse) {
@@ -353,10 +371,11 @@ function try_serialize(data: any) {
 	}
 }
 
-function try_read(file: string) {
+function exists(file: string) {
 	try {
-		return fs.readFileSync(file, 'utf-8');
+		fs.statSync(file);
+		return true;
 	} catch (err) {
-		return null;
+		return false;
 	}
 }
\ No newline at end of file