Merge pull request #427 from preactjs/no-cache-hmr

.changeset/large-apes-perform.md

@@ -0,0 +1,5 @@
+---
+'wmr': patch
+---
+
+Fix case where the module-graph would become stale if two co-dependent modules would import the same file, when this file would get updated we'd only cache-bust the import in one of those two files making the graph stale. One file updates the old version and the other updates the new one.

packages/wmr/demo/public/index.tsx

@@ -53,4 +53,4 @@ export async function prerender(data) {
 }
 
 // @ts-ignore
-if (module.hot) module.hot.accept(u => render(<u.module.App />, document.body));
+if (module.hot) module.hot.accept(u => hydrate(<u.module.App />, document.body));

packages/wmr/demo/public/lib/loc.js

@@ -39,7 +39,6 @@ export const exec = (url, route, matches) => {
 
 	return matches;
 };
-
 export function LocationProvider(props) {
 	const [url, route] = useReducer(UPDATE, location.pathname + location.search);
 

packages/wmr/src/lib/websocket-server.js

@@ -19,12 +19,14 @@ export default class WebSocketServer extends ws.Server {
 		client.on('message', function (data) {
 			const message = JSON.parse(data.toString());
 			if (message.type === 'hotAccepted') {
-				if (!moduleGraph.has(message.id)) {
-					moduleGraph.set(message.id, { dependencies: new Set(), dependents: new Set(), acceptingUpdates: false });
+				const [id] = message.id.split('?');
+				if (!moduleGraph.has(id)) {
+					moduleGraph.set(id, { dependencies: new Set(), dependents: new Set(), acceptingUpdates: false });
 				}
 
-				const entry = moduleGraph.get(message.id);
+				const entry = moduleGraph.get(id);
 				entry.acceptingUpdates = true;
+				entry.stale = false;
 			}
 		});
 	}

packages/wmr/src/wmr-middleware.js

@@ -399,7 +399,6 @@ export const TRANSFORMS = {
 				const specModule = moduleGraph.get(modSpec);
 				specModule.dependents.add(importer);
 				if (specModule.stale) {
-					specModule.stale = false;
 					return spec + `?t=${Date.now()}`;
 				}
 

packages/wmr/test/fixtures.test.js

@@ -248,6 +248,30 @@ describe('fixtures', () => {
 			expect(text).toEqual('3');
 		});
 
+		it('should bubble up updates in non-accepted files with multiple parents', async () => {
+			await loadFixture('hmr', env);
+			instance = await runWmrFast(env.tmp.path);
+			await getOutput(env, instance);
+
+			let homeFoo = await env.page.$('#home-foo');
+			let rootFoo = await env.page.$('#root-foo');
+			let homeText = homeFoo ? await homeFoo.evaluate(el => el.textContent) : null;
+			let rootText = rootFoo ? await rootFoo.evaluate(el => el.textContent) : null;
+			expect(homeText).toEqual('42');
+			expect(rootText).toEqual('42');
+
+			await updateFile(env.tmp.path, 'store.js', content => content.replace('42', '43'));
+
+			await timeout(2000);
+
+			homeFoo = await env.page.$('#home-foo');
+			rootFoo = await env.page.$('#root-foo');
+			homeText = homeFoo ? await homeFoo.evaluate(el => el.textContent) : null;
+			rootText = rootFoo ? await rootFoo.evaluate(el => el.textContent) : null;
+			expect(homeText).toEqual('43');
+			expect(rootText).toEqual('43');
+		});
+
 		it('should hot reload for a newly created file', async () => {
 			await loadFixture('hmr', env);
 			instance = await runWmrFast(env.tmp.path);

packages/wmr/test/fixtures/hmr/home.js

@@ -1,9 +1,11 @@
+import { FOO } from './store.js';
 import useCounter from './useCounter.js';
 
 function Home() {
 	const [count, increment] = useCounter();
 	return (
 		<div>
+			<p id="home-foo">{FOO}</p>
 			<p class="home">Home</p>
 			<p class="count">{count}</p>
 			<p class="increment" onClick={increment}>

packages/wmr/test/fixtures/hmr/index.js

@@ -1,11 +1,13 @@
 import { render } from 'preact';
 import styles from './style.module.css';
 import Home from './home.js';
+import { FOO } from './store.js';
 
 export function App() {
 	return (
 		<main class={styles.app}>
 			<header>
+				<p id="root-foo">{FOO}</p>
 				<nav>
 					<a href="/">Home</a>
 				</nav>

packages/wmr/test/fixtures/hmr/store.js

@@ -0,0 +1 @@
+export const FOO = 42;