UnhandledPromiseRejectionWarning: Error: Failed to launch browser!

First of all, thanks for the work on this project! The prospect of a more platform-agnostic alternative to Puppeteer is exciting.

I’m trying to run the example project locally and ran into an issue, hoping maybe someone can point me in the right direction.

The issue

I have a file, test.ts:

const pw = require('playwright');

(async () => {
  const browser = await pw.firefox.launch({ headless: false }); // 'webkit', 'chromium', 'firefox'
  const context = await browser.newContext();
  const page = await context.newPage();

  await page.goto('https://www.example.com/');
  await page.screenshot({ path: 'example.png' });

  await browser.close();
})();

When I run node test.ts I get the following error:

 UnhandledPromiseRejectionWarning: Error: Failed to launch browser!


TROUBLESHOOTING: https://github.com/Microsoft/playwright/blob/master/docs/troubleshooting.md

    at onClose (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/server/processLauncher.js:135:20)
    at Interface.helper_1.helper.addEventListener (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/server/processLauncher.js:128:65)
    at Interface.emit (events.js:202:15)
    at Interface.close (readline.js:395:8)
    at Socket.onend (readline.js:173:10)
    at Socket.emit (events.js:202:15)
    at endReadableNT (_stream_readable.js:1129:12)
    at processTicksAndRejections (internal/process/next_tick.js:76:17)
  -- ASYNC --
    at FFPlaywright.<anonymous> (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/helper.js:54:23)
    at FFPlaywright.launch (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/server/ffPlaywright.js:63:35)
    at FFPlaywright.<anonymous> (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/helper.js:55:31)
    at /mnt/c/Users/joshs/repos/Bullet/api/test.ts:4:36
    at Object.<anonymous> (/mnt/c/Users/joshs/repos/Bullet/api/test.ts:12:3)
    at Module._compile (internal/modules/cjs/loader.js:734:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:745:10)
    at Module.load (internal/modules/cjs/loader.js:626:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:566:12)
    at Function.Module._load (internal/modules/cjs/loader.js:558:3)    
  -- ASYNC --
    at FFPlaywright.<anonymous> (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/helper.js:54:23)
    at /mnt/c/Users/joshs/repos/Bullet/api/test.ts:4:36
    at Object.<anonymous> (/mnt/c/Users/joshs/repos/Bullet/api/test.ts:12:3)
    at Module._compile (internal/modules/cjs/loader.js:734:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:745:10)
    at Module.load (internal/modules/cjs/loader.js:626:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:566:12)
    at Function.Module._load (internal/modules/cjs/loader.js:558:3)    
    at Function.Module.runMain (internal/modules/cjs/loader.js:797:12) 
    at executeUserCode (internal/bootstrap/node.js:526:15)
(node:9422) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:9422) [DEP0018] DeprecationWarning: Unhandled promise rejections 
are deprecated. In the future, promise rejections that are not handled 
will terminate the Node.js process with a non-zero exit code.

What I’m running

I’m running WSL on Windows 10, Node 11.9.0.

What I’ve tried

I had similar code integrated more deeply into an application I’m working on. I pulled the code out into the simplest reproducible case I could, which is the code above.

I’ve tried switching between firefox, chromium, and webkit. I’ve also tried setting headless to false.

Any help or guidance you might be able to offer is appreciated!

[tyler-graham-ck]

In the meantime it appears that running node ./node_modules/playwright/install.js before executing your tests will download the binaries if necessary

[JoelEinbinder]

Thanks for joining us on the bleeding edge!

Did you run both npm install and node test.ts from within WSL? Installing from windows but running from within WSL, or vice versa, would probably cause this error.

Assuming your WSL is Ubuntu based, you probably need to get Chrome’s dependencies. It looks like we are missing the list of what those dependencies actually are, but I’d try

sudo apt install \
    gconf-service \
    libasound2 \
    libatk1.0-0 \
    libatk-bridge2.0-0 \
    libc6 \
    libcairo2 \
    libcups2 \
    libdbus-1-3 \
    libexpat1 \
    libfontconfig1 \
    libgcc1 \
    libgconf-2-4 \
    libgdk-pixbuf2.0-0 \
    libglib2.0-0 \
    libgtk-3-0 \
    libnspr4 \
    libpango-1.0-0 \
    libpangocairo-1.0-0 \
    libstdc++6 \
    libx11-6 \
    libx11-xcb1 \
    libxcb1 \
    libxcomposite1 \
    libxcursor1 \
    libxdamage1 \
    libxext6 \
    libxfixes3 \
    libxi6 \
    libxrandr2 \
    libxrender1 \
    libxss1 \
    libxtst6 \
    ca-certificates \
    fonts-liberation \
    libappindicator1 \
    libnss3 \
    lsb-release \
    xdg-utils \
    wget

You can also launch with the dumpio: true option, to see if there is something helpful being logged by the browser itself.