Add Playwright smoke test for core editor functionality

e2e/tests/smoke.spec.js

@@ -0,0 +1,24 @@
+const { test, expect } = require('@playwright/test');
+
+test.describe('Editor Smoke Test', () => {
+
+  test.beforeEach(async ({ page }) => {
+    await page.goto('/');
+    await expect(page.locator('.CodeMirror')).toBeVisible({ timeout: 15000 });
+  });
+
+  test('play button runs sketch', async ({ page }) => {
+    const playButton = page.locator('#play-sketch');
+
+    await expect(playButton).toBeVisible();
+    await playButton.click({ force: true });
+
+    // wait for preview trigger
+    await page.waitForTimeout(2000);
+
+    // ✅ ONLY reliable signal
+    const iframe = page.locator('iframe');
+    await expect(iframe).toBeVisible();
+  });
+
+});

package.json

@@ -3,6 +3,9 @@
   "version": "2.20.6",
   "description": "The web editor for p5.js.",
   "scripts": {
+    "test:e2e": "playwright test",
+    "test:e2e:headed": "playwright test --headed",
+    "test:e2e:debug": "playwright test --debug",
     "clean": "rimraf dist",
     "start": "cross-env BABEL_DISABLE_CACHE=1 NODE_ENV=development nodemon index.js",
     "start:prod": "cross-env NODE_ENV=production node index.js",
@@ -97,6 +100,7 @@
     "url": "git+https://github.com/catarak/p5.js-web-editor.git"
   },
   "devDependencies": {
+    "@playwright/test": "^1.45.0",
     "@babel/eslint-parser": "^7.17.0",
     "@babel/plugin-proposal-class-properties": "^7.14.5",
     "@babel/plugin-proposal-decorators": "^7.14.5",

playwright.config.js

@@ -0,0 +1,25 @@
+const { defineConfig, devices } = require('@playwright/test');
+
+module.exports = defineConfig({
+  testDir: './e2e/tests',
+
+  use: {
+    baseURL: process.env.BASE_URL || 'http://localhost:8000',
+    headless: true,
+    actionTimeout: 10000,
+  },
+
+  projects: [
+    {
+      name: 'chromium',
+      use: { ...devices['Desktop Chrome'] },
+    },
+  ],
+
+  webServer: {
+    command: 'npm run start',
+    url: 'http://localhost:8000',
+    timeout: 120000,
+    reuseExistingServer: !process.env.CI,
+  },
+});

test-results/.last-run.json

@@ -0,0 +1,4 @@
+{
+  "status": "passed",
+  "failedTests": []
+}