feat: Add Playwright e2e tests for demo and fix scroll settle race

.github/workflows/check-types.yml

@@ -10,9 +10,9 @@ jobs:
   check-types:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: pnpm/action-setup@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v6
+      - uses: pnpm/action-setup@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: 24
           cache: 'pnpm'

.github/workflows/e2e.yml

@@ -0,0 +1,39 @@
+name: E2E Tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  e2e:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    defaults:
+      run:
+        working-directory: demo
+
+    steps:
+      - uses: actions/checkout@v6
+      - uses: pnpm/action-setup@v5
+      - uses: actions/setup-node@v6
+        with:
+          node-version: 24
+          cache: 'pnpm'
+
+      - run: pnpm install
+        working-directory: .
+
+      - name: Install Playwright browsers
+        run: pnpm exec playwright install --with-deps chromium
+
+      - name: Run e2e tests
+        run: pnpm test:e2e
+
+      - uses: actions/upload-artifact@v7
+        if: failure()
+        with:
+          name: playwright-report
+          path: demo/playwright-report/
+          retention-days: 30

.github/workflows/format.yml

@@ -10,9 +10,9 @@ jobs:
   format:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: pnpm/action-setup@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v6
+      - uses: pnpm/action-setup@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: 24
           cache: 'pnpm'

.github/workflows/lint.yml

@@ -10,10 +10,9 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: pnpm/action-setup@v4
-
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v6
+      - uses: pnpm/action-setup@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: 24
           cache: 'pnpm'

.gitignore

@@ -7,3 +7,4 @@ dist/
 *.db-wal2
 rocicorp-zero-virtual-*.tgz
 docs
+.last-run.json

demo/.env

@@ -2,3 +2,5 @@ AUTH_SECRET="abcd"
 ZERO_UPSTREAM_DB="postgresql://user:password@127.0.0.1:5430/postgres"
 ZERO_QUERY_URL="http://localhost:*/api/zero/query"
 ZERO_MUTATE_URL="http://localhost:*/api/zero/mutate"
+VITE_PUBLIC_CACHE_PORT=5858
+

demo/e2e/global-setup.ts

@@ -0,0 +1,180 @@
+import {spawn} from 'node:child_process';
+import {
+  existsSync,
+  mkdirSync,
+  readFileSync,
+  rmSync,
+  writeFileSync,
+} from 'node:fs';
+import * as net from 'node:net';
+import {join} from 'node:path';
+import {fileURLToPath} from 'node:url';
+import pg from 'pg';
+import {seedTestDb} from './seed-test.ts';
+
+const DEMO_DIR = fileURLToPath(new URL('..', import.meta.url));
+
+// Replica dir is wiped on each run so zero-cache starts with clean data.
+const REPLICA_DIR = '/tmp/zero-playwright-replica';
+export const REPLICA_FILE = join(REPLICA_DIR, 'replica');
+
+// PID file lets globalTeardown kill the zero-cache process.
+export const PID_FILE = '/tmp/zero-playwright.pid';
+
+export default async function globalSetup(): Promise<void> {
+  console.log('\n[setup] Starting postgres...');
+  await startPostgres();
+
+  console.log('[setup] Waiting for postgres...');
+  await waitForPort(5430);
+  await waitForPostgres();
+
+  console.log('[setup] Seeding test data...');
+  await seedTestDb(process.env['ZERO_UPSTREAM_DB']!);
+
+  console.log('[setup] Clearing zero-cache replica...');
+  killExistingZeroCache();
+  if (existsSync(REPLICA_DIR)) {
+    rmSync(REPLICA_DIR, {recursive: true, force: true});
+  }
+  mkdirSync(REPLICA_DIR, {recursive: true});
+
+  const port = Number(process.env['VITE_PUBLIC_CACHE_PORT'] ?? 5858);
+  console.log('[setup] Starting zero-cache...');
+  const zeroCacheProc = spawnZeroCache(port);
+  writeFileSync(PID_FILE, String(zeroCacheProc.pid));
+
+  console.log(`[setup] Waiting for zero-cache on port ${port}...`);
+  await waitForPort(port, 60_000);
+  console.log('[setup] Ready.\n');
+}
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+async function startPostgres(): Promise<void> {
+  await new Promise<void>((resolve, reject) => {
+    const proc = spawn(
+      'docker',
+      [
+        'compose',
+        '--env-file',
+        '.env',
+        '-f',
+        './docker/docker-compose.yml',
+        'up',
+        '-d',
+      ],
+      {cwd: DEMO_DIR, stdio: 'inherit'},
+    );
+    proc.on('exit', code => {
+      if (code === 0) resolve();
+      else reject(new Error(`docker compose up exited with code ${code}`));
+    });
+    proc.on('error', reject);
+  });
+}
+
+async function waitForPostgres(timeoutMs = 30_000): Promise<void> {
+  const connStr = process.env['ZERO_UPSTREAM_DB']!;
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    try {
+      const pool = new pg.Pool({connectionString: connStr, max: 1});
+      const client = await pool.connect();
+      client.release();
+      await pool.end();
+      return;
+    } catch {
+      await sleep(500);
+    }
+  }
+  throw new Error('Postgres not ready within timeout');
+}
+
+function waitForPort(port: number, timeoutMs = 30_000): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const deadline = Date.now() + timeoutMs;
+
+    function tryConnect() {
+      const socket = new net.Socket();
+      socket.setTimeout(1_000);
+
+      socket.on('connect', () => {
+        socket.destroy();
+        resolve();
+      });
+
+      const retry = () => {
+        socket.destroy();
+        if (Date.now() >= deadline) {
+          reject(new Error(`Port ${port} not available after ${timeoutMs}ms`));
+          return;
+        }
+        setTimeout(tryConnect, 500);
+      };
+
+      socket.on('timeout', retry);
+      socket.on('error', retry);
+      socket.connect(port, '127.0.0.1');
+    }
+
+    tryConnect();
+  });
+}
+
+function spawnZeroCache(port: number) {
+  const binDir = join(DEMO_DIR, 'node_modules', '.bin');
+  const env: NodeJS.ProcessEnv = {
+    ...process.env,
+    // Ensure node_modules/.bin is on PATH so zero-cache-dev can find zero-cache.
+    PATH: `${binDir}:${process.env['PATH'] ?? ''}`,
+    ZERO_REPLICA_FILE: REPLICA_FILE,
+    ZERO_LOG_LEVEL: 'error',
+  };
+
+  // Prefer the local bin so we use the exact version pinned in demo/package.json.
+  const bin = join(DEMO_DIR, 'node_modules', '.bin', 'zero-cache-dev');
+  const command = existsSync(bin) ? bin : 'zero-cache-dev';
+
+  const proc = spawn(command, ['--port', String(port)], {
+    cwd: DEMO_DIR,
+    env,
+    stdio: ['ignore', 'pipe', 'pipe'],
+    detached: true,
+  });
+
+  proc.stdout?.on('data', (d: Buffer) =>
+    process.stdout.write(`[zero-cache] ${d}`),
+  );
+  proc.stderr?.on('data', (d: Buffer) =>
+    process.stderr.write(`[zero-cache] ${d}`),
+  );
+
+  proc.on('exit', code => {
+    if (code !== null && code !== 0) {
+      console.error(`[zero-cache] exited with code ${code}`);
+    }
+  });
+
+  proc.unref();
+  return proc;
+}
+
+function killExistingZeroCache(): void {
+  if (!existsSync(PID_FILE)) return;
+  const pid = parseInt(readFileSync(PID_FILE, 'utf-8').trim(), 10);
+  if (!isNaN(pid)) {
+    try {
+      process.kill(pid, 'SIGTERM');
+    } catch {
+      // Process may already be gone — that's fine.
+    }
+  }
+  rmSync(PID_FILE, {force: true});
+}
+
+function sleep(ms: number): Promise<void> {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}

demo/e2e/global-teardown.ts

@@ -0,0 +1,17 @@
+import {existsSync, readFileSync, rmSync} from 'node:fs';
+import {PID_FILE} from './global-setup.ts';
+
+export default async function globalTeardown(): Promise<void> {
+  if (!existsSync(PID_FILE)) return;
+
+  const pid = parseInt(readFileSync(PID_FILE, 'utf-8').trim(), 10);
+  if (!isNaN(pid)) {
+    try {
+      process.kill(pid, 'SIGTERM');
+      console.log(`[teardown] Stopped zero-cache (pid ${pid})`);
+    } catch {
+      // Already gone — that's fine.
+    }
+  }
+  rmSync(PID_FILE, {force: true});
+}