Add tests

e2e/playwright.config.js

@@ -0,0 +1,25 @@
+import { defineConfig } from "@playwright/test";
+
+const port = process.env.E2E_PORT || "8765";
+
+export default defineConfig({
+  testDir: "tests",
+  // One seeded wiki is shared, and tests mutate it: run serially.
+  workers: 1,
+  fullyParallel: false,
+  reporter: "list",
+  use: {
+    baseURL: `http://127.0.0.1:${port}`,
+    // System Chrome; no Playwright browser download needed.
+    channel: "chrome",
+    trace: "retain-on-failure",
+    screenshot: "only-on-failure",
+  },
+  webServer: {
+    command: "node server.mjs",
+    url: `http://127.0.0.1:${port}/`,
+    timeout: 120_000,
+    reuseExistingServer: false,
+    stdout: "pipe",
+  },
+});