playwright-interactive

Playwright Interactive Skill

Use a persistent js_repl Playwright session to debug local web or Electron apps, keep the same handles alive across iterations, and run functional plus visual QA without restarting the whole toolchain unless the process ownership changed.

Preconditions

• js_repl must be enabled for this skill.
• If js_repl is missing, enable it in ~/.codex/config.toml:

[features]
js_repl = true

• You can also start a new session with --enable js_repl (equivalent to -c features.js_repl=true).
• After enabling js_repl, start a new Codex session so the tool list refreshes.
• For now, run this workflow with sandboxing disabled: start Codex with --sandbox danger-full-access (or the equivalent config for sandbox_mode=danger-full-access). This is a temporary requirement while js_repl + Playwright support inside the sandbox is still being completed.
• Run setup from the same project directory you need to debug.
• Treat js_repl_reset as a recovery tool, not routine cleanup. Resetting the kernel destroys your Playwright handles.

One-time setup

test -f package.json || npm init -y
npm install playwright
# Web-only, for headed Chromium or mobile emulation:
# npx playwright install chromium
# Electron-only, and only if the target workspace is the app itself:
# npm install --save-dev electron
node -e "import('playwright').then(() => console.log('playwright import ok')).catch((error) => { console.error(error); process.exit(1); })"

If you switch to a different workspace later, repeat setup there.

Core Workflow

1. Write a brief QA inventory before testing:
   • Build the inventory from three sources: the user's requested requirements, the user-visible features or behaviors you actually implemented, and the claims you expect to make in the final response.
   • Anything that appears in any of those three sources must map to at least one QA check before signoff.
   • List the user-visible claims you intend to sign off on.
   • List every meaningful user-facing control, mode switch, or implemented interactive behavior.
   • List the state changes or view changes each control or implemented behavior can cause.
   • Use this as the shared coverage list for both functional QA and visual QA.
   • For each claim or control-state pair, note the intended functional check, the specific state where the visual check must happen, and the evidence you expect to capture.
   • If a requirement is visually central but subjective, convert it into an observable QA check instead of leaving it implicit.
   • Add at least 2 exploratory or off-happy-path scenarios that could expose fragile behavior.
2. Run the bootstrap cell once.
3. Start or confirm any required dev server in a persistent TTY session.
4. Launch the correct runtime and keep reusing the same Playwright handles.
5. After each code change, reload for renderer-only changes or relaunch for main-process/startup changes.
6. Run functional QA with normal user input.
7. Run a separate visual QA pass.
8. Verify viewport fit and capture the screenshots needed to support your claims.
9. Clean up the Playwright session only when the task is actually finished.

Bootstrap (Run Once)

var chromium;
var electronLauncher;
var browser;
var context;
var page;
var mobileContext;
var mobilePage;
var electronApp;
var appWindow;

try {
  ({ chromium, _electron: electronLauncher } = await import("playwright"));
  console.log("Playwright loaded");
} catch (error) {
  throw new Error(
    `Could not load playwright from the current js_repl cwd. Run the setup commands from this workspace first. Original error: ${error}`
  );
}

Binding rules:

• Use var for the shared top-level Playwright handles because later js_repl cells reuse them.
• The setup cells below are intentionally short happy paths. If a handle looks stale, set that binding to undefined and rerun the cell instead of adding recovery logic everywhere.
• Prefer one named handle per surface you care about (page, mobilePage, appWindow) over repeatedly rediscovering pages from the context.

Shared web helpers:

var resetWebHandles = function () {
  context = undefined;
  page = undefined;
  mobileContext = undefined;
  mobilePage = undefined;
};

var ensureWebBrowser = async function () {
  if (browser && !browser.isConnected()) {
    browser = undefined;
    resetWebHandles();
  }

  browser ??= await chromium.launch({ headless: false });
  return browser;
};

var reloadWebContexts = async function () {
  for (const currentContext of [context, mobileContext]) {
    if (!currentContext) continue;
    for (const p of currentContext.pages()) {
      await p.reload({ waitUntil: "domcontentloaded" });
    }
  }
  console.log("Reloaded existing web tabs");
};

Choose Session Mode

For web apps, use an explicit viewport by default and treat native-window mode as a separate validation pass.

• Use an explicit viewport for routine iteration, breakpoint checks, reproducible screenshots, snapshot diffs, and model-assisted localization. This is the default because it is stable across machines and avoids host window-manager variability.
• When you need deterministic high-DPI behavior, keep the explicit viewport and add deviceScaleFactor rather than switching straight to native-window mode.
• Use native-window mode (viewport: null) for a separate headed pass when you need to validate launched window size, OS-level DPI behavior, browser chrome interactions, or bugs that may depend on the host display configuration.
• For Electron, assume native-window behavior all the time. Electron launches through Playwright with noDefaultViewport, so treat it like a real desktop window and check the as-launched size and layout before resizing anything.
• When signoff depends on both layout breakpoints and real desktop behavior, do both passes: explicit viewport first for deterministic QA, then native-window validation for final environment-specific checks.
• Treat switching modes as a context reset. Do not reuse a viewport-emulated context for a native-window pass or vice versa; close the old page and context, then create a new one for the new mode.

Start or Reuse Web Session

Desktop and mobile web sessions share the same browser, helpers, and QA flow. The main difference is which context and page pair you create.

Desktop Web Context

Set TARGET_URL to the app you are debugging. For local servers, prefer 127.0.0.1 over localhost.

var TARGET_URL = "http://127.0.0.1:3000";

if (page?.isClosed()) page = undefined;

await ensureWebBrowser();
context ??= await browser.newContext({
  viewport: { width: 1600, height: 900 },
});
page ??= await context.newPage();

await page.goto(TARGET_URL, { waitUntil: "domcontentloaded" });
console.log("Loaded:", await page.title());

If context or page is stale, set context = page = undefined and rerun the cell.

Mobile Web Context

Reuse TARGET_URL when it already exists; otherwise set a mobile target directly.

var MOBILE_TARGET_URL = typeof TARGET_URL === "string"
  ? TARGET_URL
  : "http://127.0.0.1:3000";

if (mobilePage?.isClosed()) mobilePage = undefined;

await ensureWebBrowser();
mobileContext ??= await browser.newContext({
  viewport: { width: 390, height: 844 },
  isMobile: true,
  hasTouch: true,
});
mobilePage ??= await mobileContext.newPage();

await mobilePage.goto(MOBILE_TARGET_URL, { waitUntil: "domcontentloaded" });
console.log("Loaded mobile:", await mobilePage.title());

If mobileContext or mobilePage is stale, set mobileContext = mobilePage = undefined and rerun the cell.

Native-Window Web Pass

var TARGET_URL = "http://127.0.0.1:3000";

await ensureWebBrowser();

await page?.close().catch(() => {});
await context?.close().catch(() => {});
page = undefined;
context = undefined;

browser ??= await chromium.launch({ headless: false });
context = await browser.newContext({ viewport: null });
page = await context.newPage();

await page.goto(TARGET_URL, { waitUntil: "domcontentloaded" });
console.log("Loaded native window:", await page.title());

Start or Reuse Electron Session

Set ELECTRON_ENTRY to . when the current workspace is the Electron app and package.json points main to the right entry file. If you need to target a specific main-process file directly, use a path such as ./main.js instead.

var ELECTRON_ENTRY = ".";

if (appWindow?.isClosed()) appWindow = undefined;

if (!appWindow && electronApp) {
  await electronApp.close().catch(() => {});
  electronApp = undefined;
}

electronApp ??= await electronLauncher.launch({
  args: [ELECTRON_ENTRY],
});

appWindow ??= await electronApp.firstWindow();

console.log("Loaded Electron window:", await appWindow.title());

If js_repl is not already running from the Electron app workspace, pass cwd explicitly when launching.

If the app process looks stale, set electronApp = appWindow = undefined and rerun the cell.

If you already have an Electron session but need a fresh process after a main-process, preload, or startup change, use the restart cell in the next section instead of rerunning this one.

Reuse Sessions During Iteration

Keep the same session alive whenever you can.

Web renderer reload:

await reloadWebContexts();

Electron renderer-only reload:

await appWindow.reload({ waitUntil: "domcontentloaded" });
console.log("Reloaded Electron window");

Electron restart after main-process, preload, or startup changes:

await electronApp.close().catch(() => {});
electronApp = undefined;
appWindow = undefined;

electronApp = await electronLauncher.launch({
  args: [ELECTRON_ENTRY],
});

appWindow = await electronApp.firstWindow();
console.log("Relaunched Electron window:", await appWindow.title());

If your launch requires an explicit cwd, include the same

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