Got working preact SSR

.npmrc

@@ -1 +1,2 @@
-auto-install-peers=true
+# Needed by pnpm to work with "@preact/preset-vite"
+shamefully-hoist=true

client/App.jsx

@@ -1,13 +1,30 @@
 import Router from 'preact-router'
+import { route } from 'preact-router'
+import { useEffect } from 'preact/hooks'
 
 import { HomePage } from './pages/Home.jsx'
 import { LoginPage } from './pages/Login.jsx'
 import { ProblemPage } from './pages/Problem.jsx'
 
-export const App = ({ path }) => (
-    <Router>
-        <HomePage path="/" />
-        <LoginPage path="/login" />
-        <ProblemPage path="/problem/:id" />
-    </Router>
-)
+const Redirect = ({ to }) => {
+    useEffect(() => {
+        route(to, true)
+    }, [])
+
+    return (
+        <>
+            Redirecting to <pre>{to}</pre>...
+        </>
+    )
+}
+
+export const App = ({ url }) => {
+    return (
+        <Router url={url}>
+            <HomePage path="/" />
+            <LoginPage path="/login" />
+            <ProblemPage path="/problem/:id" />
+            <Redirect default to="/" />
+        </Router>
+    )
+}

client/Router.jsx

@@ -1,79 +0,0 @@
-import { useSignal } from '@preact/signals'
-import { useEffect, useMemo } from 'preact/hooks'
-
-import URLPattern from 'url-pattern'
-
-export const Router = ({ pages }) => {
-    const compiledRoutes = useMemo(
-        () =>
-            Object.entries(pages).map(([pattern, Page]) => ({
-                pattern: new URLPattern(pattern),
-                Page,
-            })),
-        [pages]
-    )
-
-    const routerUrl = useSignal(location.hash.slice(1))
-
-    useEffect(() => {
-        window.addEventListener('hashchange', () => {
-            routerUrl.value = location.hash.slice(1)
-        })
-    }, [])
-
-    const route = compiledRoutes.flatMap(({ pattern, Page }) => {
-        const m = pattern.match(routerUrl.value.split('?', 1)[0])
-        return m ? [{ Page, params: m }] : []
-    })?.[0]
-
-    if (!route) {
-        console.log(`Invalid route "${routerUrl.value}", redirecting to homepage`)
-
-        location.href = '/#/'
-        routerUrl.value = '/'
-
-        return <>Redirecting...</>
-    }
-
-    const { Page, params } = route
-
-    const queryPart =
-        routerUrl.value.indexOf('?') === -1
-            ? ''
-            : routerUrl.value.slice(routerUrl.value.indexOf('?') + 1)
-    console.log(queryPart)
-
-    const queryParams =
-        queryPart?.length > 0
-            ? Object.fromEntries(
-                  queryPart.split('&').map(kvPart => {
-                      const eqIndex = kvPart.indexOf('=')
-                      return eqIndex === -1
-                          ? [kvPart, true]
-                          : [
-                                kvPart.slice(0, eqIndex),
-                                decodeURIComponent(kvPart.slice(eqIndex + 1)),
-                            ]
-                  })
-              )
-            : {}
-
-    return <Page params={params} query={queryParams} />
-}
-
-export const Link = ({ page, params, query, children }) => {
-    for (const [key, value] of Object.entries(params ?? {})) {
-        page = page.replace(':' + key, encodeURIComponent(value))
-    }
-
-    let targetHref = page
-    if (query) {
-        targetHref +=
-            '?' +
-            Object.entries(query ?? {})
-                .map(([key, value]) => `${key}=${encodeURIComponent(value)}`)
-                .join('&')
-    }
-
-    return <a href={'/#' + targetHref}>{children}</a>
-}

client/components/Problem.jsx

@@ -1,4 +1,3 @@
-import { Link } from '../Router.jsx'
 import { Markdown } from './Markdown.jsx'
 
 export const Problem = ({ id, content }) => {
@@ -6,9 +5,7 @@ export const Problem = ({ id, content }) => {
         <div class="problem">
             <div class="problem-header">
                 <div class="problem-title">
-                    <Link page={`/problem/:id`} params={{ id }}>
-                        Problema {id}
-                    </Link>
+                    <a href={`/problem/${id}`}>Problema {id}</a>
                 </div>
             </div>
             <div class="problem-content">

client/entry-client.jsx

@@ -0,0 +1,4 @@
+import { hydrate } from 'preact'
+import { App } from './App.jsx'
+
+hydrate(<App />, document.body)

client/entry-server.jsx

@@ -0,0 +1,6 @@
+import renderToString from 'preact-render-to-string'
+import { App } from './App.jsx'
+
+export function render(url) {
+    return renderToString(<App url={url} />)
+}

client/hooks.jsx

@@ -1,15 +1,24 @@
 import { useEffect, useState } from 'preact/hooks'
 
 export const useUser = () => {
-    const [username, setUsername] = useState(null)
+    const [user, setUser] = useState(null)
+
+    const logout = () => {
+        setUser(null)
+    }
 
     useEffect(async () => {
         const res = await fetch(`/api/current-user`, {
             credentials: 'include',
         })
-        const username = await res.json()
-        setUsername(username)
+
+        if (res.ok) {
+            const user = await res.json()
+            setUser(user)
+        }
     }, [])
 
-    return { username }
+    console.log(user)
+
+    return [user, logout]
 }

client/pages/Home.jsx

@@ -1,15 +1,19 @@
+import { route } from 'preact-router'
+
 import { Problem } from '../components/Problem.jsx'
 import { useUser } from '../hooks.jsx'
 
 export const HomePage = () => {
-    const { username } = useUser()
+    console.log('rendering homepage')
 
-    const logout = async () => {
+    const [user, logout] = useUser()
+
+    const handleLogout = async () => {
         await fetch(`/api/logout`, {
             method: 'POST',
         })
 
-        location.reload()
+        logout()
     }
 
     const problems = Array.from({ length: 20 }, (_, i) => ({
@@ -24,10 +28,10 @@ export const HomePage = () => {
         <main class="home">
             <div class="logo">PHC / Problemi</div>
             <div class="subtitle">
-                {username ? (
+                {user ? (
                     <>
-                        Logged in as {username} (
-                        <span class="link" onClick={() => logout()}>
+                        Logged in as {user.username} (
+                        <span class="link" onClick={handleLogout}>
                             Logout
                         </span>
                         )

client/pages/Login.jsx

@@ -1,3 +1,5 @@
+import { route } from 'preact-router'
+
 import { useState } from 'preact/hooks'
 
 export const LoginPage = () => {
@@ -14,7 +16,7 @@ export const LoginPage = () => {
             }),
         })
 
-        location.href = '/#/'
+        route('/')
     }
 
     return (

index.html

@@ -18,10 +18,11 @@
             rel="stylesheet"
         />
 
-        <link rel="stylesheet" href="./node_modules/katex/dist/katex.css" />
-        <link rel="stylesheet" href="./styles/main.scss" />
+        <link rel="stylesheet" href="/node_modules/katex/dist/katex.css" />
+        <link rel="stylesheet" href="/client/styles/main.scss" />
     </head>
     <body>
-        <script type="module" src="./src/main.jsx"></script>
+        <!-- SSR OUTLET -->
+        <script type="module" src="/client/entry-client.jsx"></script>
     </body>
 </html>

package.json

@@ -5,9 +5,11 @@
     "main": "index.js",
     "type": "module",
     "scripts": {
-        "start:frontend": "cd frontend && npm run dev",
-        "start:server": "node ./main.js",
-        "start": "concurrently npm:start:server npm:start:frontend"
+        "dev": "MODE=development node server.js",
+        "build": "run-s build:client build:server",
+        "build:client": "vite build --outDir dist/client",
+        "build:server": "vite build --ssr client/entry-server.jsx --outDir dist/server",
+        "serve": "node server.js"
     },
     "license": "MIT",
     "dependencies": {

server.js

@@ -3,28 +3,79 @@ import fs from 'fs/promises'
 
 import { createServer as createViteServer } from 'vite'
 import express from 'express'
+import { createApiRouter } from './server/routers.js'
 
-const CONSTANTS = {
-    MODE_DEVELOPMENT: 'development',
+const config = {
+    isDevelopment: process.env.MODE === 'development',
+    port: process.env.PORT || 3000,
 }
 
-async function createDevelopmentServer(app) {
+console.dir(config)
+
+async function createDevRouter() {
+    const r = express.Router()
+
     const vite = await createViteServer({
         server: { middlewareMode: true },
         appType: 'custom',
     })
 
-    app.use(vite.middlewares)
+    r.use(vite.middlewares)
+    r.use('*', async (req, res, next) => {
+        try {
+            const indexHtml = await fs.readFile(path.resolve('./index.html'), 'utf-8')
+            const transformedTemplate = await vite.transformIndexHtml(req.originalUrl, indexHtml)
 
-    app.use('*', async (req, res) => {
-        // serve index.html
-        const indexHtml = await fs.readFile(path.resolve('./client/index.html'), 'utf-8')
-        const transformedIndexHtml = vite.transformIndexHtml(req.originalUrl, indexHtml)
+            // Load (to be bundled) entry point for server side rendering
+            const { render } = await vite.ssrLoadModule('./client/entry-server.jsx')
+
+            const html = transformedTemplate.replace('<!-- SSR OUTLET -->', render(req.originalUrl))
+
+            res.send(html)
+        } catch (error) {
+            vite.ssrFixStacktrace(error)
+            next(error)
+        }
+    })
+
+    return r
+}
+
+async function createProductionRouter() {
+    // Load bundled entry point for server side rendering
+    const { render } = await import('./dist/server/entry-server.js')
+
+    const r = new express.Router()
+
+    r.use('/', express.static('dist/client'))
+    r.use('*', async (req, res) => {
+        const transformedTemplate = await fs.readFile(
+            path.resolve('./dist/client/index.html'),
+            'utf-8'
+        )
+
+        const html = transformedTemplate.replace('<!-- SSR OUTLET -->', render(req.originalUrl))
+
+        res.send(html)
+    })
+
+    return r
+}
+
+async function main() {
+    const app = express()
+
+    app.use('/', await createApiRouter())
+
+    if (config.isDevelopment) {
+        app.use('/', await createDevRouter())
+    } else {
+        app.use('/', await createProductionRouter())
+    }
+
+    app.listen(config.port, () => {
+        console.log(`Listening on port ${config.port}...`)
     })
 }
 
-function createProductionServer() {
-    app.use('/', express.static('client/dist'))
-}
-
-const app = express()
+main()

server/db/example-data.js

@@ -0,0 +1,7 @@
+export const initialDatabaseValue = {
+    users: {
+        ['BachoSeven']: {},
+        ['aziis98']: {},
+    },
+    problems: {},
+}

server/main.js

@@ -1,79 +0,0 @@
-import express from 'express'
-
-import crypto from 'crypto'
-
-// import serveStatic from 'serve-static'
-import bodyParser from 'body-parser'
-import cookieParser from 'cookie-parser'
-
-import { authMiddleware, loggingMiddleware, PingRouter, StatusRouter } from './server/routes.js'
-import { createDatabase, getUser, updateUser } from './server/db/database.js'
-
-const app = express()
-
-const sessions = {
-    store: {},
-    createSession(username) {
-        const sid = crypto.randomBytes(10).toString('hex')
-        this.store[sid] = username
-        return sid
-    },
-    getUserForSession(sid) {
-        return this.store[sid] ?? null
-    },
-}
-
-const db = createDatabase('./db.local.json', {
-    users: {
-        ['BachoSeven']: {},
-        ['aziis98']: {},
-    },
-    problems: {},
-})
-
-app.use(bodyParser.json())
-app.use(cookieParser())
-
-app.use(loggingMiddleware)
-app.use(authMiddleware(sid => sessions.getUserForSession(sid)))
-
-app.use('/api/status', new StatusRouter())
-app.use('/api/ping', new PingRouter())
-
-app.get('/api/current-user', (req, res) => {
-    res.json(sessions.getUserForSession(req.cookies.sid))
-})
-
-app.post('/api/login', (req, res) => {
-    const { username } = req.body
-    res.cookie('sid', sessions.createSession(username), { maxAge: 1000 * 60 * 60 * 24 * 7 })
-    res.json({ status: 'ok' })
-})
-
-app.post('/api/logout', (req, res) => {
-    res.cookie('sid', '', { expires: new Date() })
-    res.json({ status: 'ok' })
-})
-
-app.get('/api/user/:id', async (req, res) => {
-    const user = await getUser(db, req.params.id)
-
-    if (user) {
-        res.json(user)
-    } else {
-        res.sendStatus(404)
-    }
-})
-
-app.post('/api/user/:id', async (req, res) => {
-    await updateUser(db, req.params.id, req.body)
-    res.sendStatus(200)
-})
-
-app.all('*', (_req, res) => {
-    res.sendStatus(404)
-})
-
-app.listen(4000, () => {
-    console.log(`Started server on port 4000...`)
-})

server/routers.js

@@ -0,0 +1,86 @@
+import crypto from 'crypto'
+
+import bodyParser from 'body-parser'
+import cookieParser from 'cookie-parser'
+
+import { authMiddleware, loggingMiddleware, PingRouter, StatusRouter } from './middlewares.js'
+import { createDatabase, getUser, updateUser } from './db/database.js'
+import express from 'express'
+import { initialDatabaseValue } from './db/example-data.js'
+import { useId } from 'preact/hooks'
+
+export async function createApiRouter() {
+    const sessions = {
+        store: {},
+        createSession(username) {
+            const sid = crypto.randomBytes(10).toString('hex')
+            this.store[sid] = username
+            return sid
+        },
+        getUserForSession(sid) {
+            return this.store[sid] ?? null
+        },
+    }
+
+    const db = createDatabase('./db.local.json', initialDatabaseValue)
+
+    const r = express.Router()
+
+    r.use(bodyParser.json())
+    r.use(cookieParser())
+
+    r.use(loggingMiddleware)
+    r.use(authMiddleware(sid => sessions.getUserForSession(sid)))
+
+    r.use('/api/status', new StatusRouter())
+    r.use('/api/ping', new PingRouter())
+
+    r.get('/api/current-user', async (req, res) => {
+        const userId = sessions.getUserForSession(req.cookies.sid)
+        if (!userId) {
+            res.cookie('sid', '', { expires: new Date() })
+            res.status(400)
+            res.end('Invalid session token')
+            return
+        }
+
+        const user = await getUser(db, userId)
+
+        res.json({
+            username: userId,
+            ...user,
+        })
+    })
+
+    r.post('/api/login', (req, res) => {
+        const { username } = req.body
+        res.cookie('sid', sessions.createSession(username), { maxAge: 1000 * 60 * 60 * 24 * 7 })
+        res.json({ status: 'ok' })
+    })
+
+    r.post('/api/logout', (req, res) => {
+        res.cookie('sid', '', { expires: new Date() })
+        res.json({ status: 'ok' })
+    })
+
+    r.get('/api/user/:id', async (req, res) => {
+        const user = await getUser(db, req.params.id)
+
+        if (user) {
+            res.json(user)
+        } else {
+            res.sendStatus(404)
+        }
+    })
+
+    r.post('/api/user/:id', async (req, res) => {
+        await updateUser(db, req.params.id, req.body)
+        res.sendStatus(200)
+    })
+
+    // r.all('*', (_req, res) => {
+    //     res.sendStatus(404)
+    // })
+
+    return r
+}