machine to check which dependencies are missing. For dependencies on Ubuntu, please refer to [Dockerfile](https://github.com/microsoft/playwright/blob/master/docs/docker/Dockerfile.bionic) which is used to run our tests.
The common ones for Debian and CentOS are provided below.
Please file new issues in this repo for things relating to Playwright.
### Setting Up Chrome Linux Sandbox
In order to protect the host environment from untrusted web content, Chrome uses [multiple layers of sandboxing](https://chromium.googlesource.com/chromium/src/+/HEAD/docs/linux_sandboxing.md). For this to work properly,
the host should be configured first. If there's no good sandbox for Chrome to use, it will crash
with the error `No usable sandbox!`.
If you **absolutely trust** the content you open in Chrome, you can launch Chrome
Make sure all the necessary dependencies are installed. You can run `ldd chrome | grep not` on a Linux
machine to check which dependencies are missing. For dependencies on Ubuntu, please refer to [Dockerfile](https://github.com/microsoft/playwright/blob/master/docs/docker/Dockerfile.bionic) which is used to run our tests.
## WebKit
### WebKit headless doesn't launch on Linux/WSL
Make sure all the necessary dependencies are installed. You can run `ldd chrome | grep not` on a Linux
machine to check which dependencies are missing. For dependencies on Ubuntu, please refer to [Dockerfile](https://github.com/microsoft/playwright/blob/master/docs/docker/Dockerfile.bionic) which is used to run our tests.
> 👋 We run our tests for Playwright on Travis CI - see our [`.travis.yml`](https://github.com/microsoft/playwright/blob/master/.travis.yml) for reference.
Tips-n-tricks:
- The `libnss3` package must be installed in order to run Chromium on Ubuntu Trusty
- [user namespace cloning](http://man7.org/linux/man-pages/man7/user_namespaces.7.html) should be enabled to support
proper sandboxing
- [xvfb](https://en.wikipedia.org/wiki/Xvfb) should be launched in order to run Chromium in non-headless mode (e.g. to test Chrome Extensions)
To sum up, your `.travis.yml` might look like this:
```yml
language: node_js
dist: trusty
addons:
apt:
packages:
# This is required to run new chrome on old trusty
> 👋 We run our tests for Playwright on CircleCI - see our [`.circleci/config.yml`](https://github.com/microsoft/playwright/blob/master/.circleci/config.yml) for reference.
This will write shared memory files into `/tmp` instead of `/dev/shm`. See [crbug.com/736452](https://bugs.chromium.org/p/chromium/issues/detail?id=736452) for more details.
Seeing other weird errors when launching Chrome? Try running your container
with `docker run --cap-add=SYS_ADMIN` when developing locally. Since the Dockerfile
If you are using a JavaScript transpiler like babel or TypeScript, calling `evaluate()` with an async function might not work. This is because while `playwright` uses `Function.prototype.toString()` to serialize functions while transpilers could be changing the output code in such a way it's incompatible with `playwright`.
Some workarounds to this problem would be to instruct the transpiler not to mess up with the code, for example, configure TypeScript to use latest ECMAScript version (`"target": "es2018"`). Another workaround could be using string templates instead of functions:
Playwright is a new project, and we are watching the issues very closely. As we solve common issues, this document will grow to include the common answers.
