docs(troubleshooting): add dependencies for firefox and webkit (#1461)

CONTRIBUTING.md

@@ -1,7 +1,5 @@
 <!-- gen:toc -->
 - [How to Contribute](#how-to-contribute)
-  * [Contributor License Agreement](#contributor-license-agreement)
-  * [Code of Conduct](#code-of-conduct)
   * [Getting Code](#getting-code)
   * [Code reviews](#code-reviews)
   * [Code Style](#code-style)
@@ -11,26 +9,12 @@
   * [Adding New Dependencies](#adding-new-dependencies)
   * [Running & Writing Tests](#running--writing-tests)
   * [Public API Coverage](#public-api-coverage)
+- [Contributor License Agreement](#contributor-license-agreement)
+  * [Code of Conduct](#code-of-conduct)
 <!-- gen:stop -->
 
 # How to Contribute
 
-## Contributor License Agreement
-
-This project welcomes contributions and suggestions.  Most contributions require you to agree to a
-Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us
-the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.
-
-When you submit a pull request, a CLA bot will automatically determine whether you need to provide
-a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions
-provided by the bot. You will only need to do this once across all repos using our CLA.
-
-## Code of Conduct
-
-This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
-For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or
-contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.
-
 ## Getting Code
 
 1. Clone this repository
@@ -226,3 +210,18 @@ npm run coverage
 
 There are also per-browser commands:" `npm run ccoverage`, `npm run fcoverage` and `npm run wcoverage`.
 
+# Contributor License Agreement
+
+This project welcomes contributions and suggestions.  Most contributions require you to agree to a
+Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us
+the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.
+
+When you submit a pull request, a CLA bot will automatically determine whether you need to provide
+a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions
+provided by the bot. You will only need to do this once across all repos using our CLA.
+
+## Code of Conduct
+
+This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
+For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or
+contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.

docs/troubleshooting.md

@@ -7,13 +7,20 @@
   * [Setting Up Chrome Linux Sandbox](#setting-up-chrome-linux-sandbox)
     - [[recommended] Enable user namespace cloning](#recommended-enable-user-namespace-cloning)
     - [[alternative] Setup setuid sandbox](#alternative-setup-setuid-sandbox)
+- [Firefox](#firefox)
+  * [Firefox headless doesn't launch on Linux/WSL](#firefox-headless-doesnt-launch-on-linuxwsl)
+- [WebKit](#webkit)
+  * [WebKit headless doesn't launch on Linux/WSL](#webkit-headless-doesnt-launch-on-linuxwsl)
+- [Running Playwright on CI](#running-playwright-on-ci)
   * [Running Playwright on Travis CI](#running-playwright-on-travis-ci)
   * [Running Playwright on CircleCI](#running-playwright-on-circleci)
   * [Running Playwright in Docker](#running-playwright-in-docker)
     - [Tips](#tips)
-- [Code Transpilation Issues](#code-transpilation-issues)
+- [Code transpilation issues](#code-transpilation-issues)
-- [ReferenceError: URL is not defined](#referenceerror-url-is-not-defined)
+- [Node requirements](#node-requirements)
+  * [ReferenceError: URL is not defined](#referenceerror-url-is-not-defined)
 <!-- GEN:stop -->
+
 ## Chromium
 
 ### Chrome headless doesn't launch on Windows
@@ -36,7 +43,9 @@ const browser = await playwright.chromium.launch({
 ### Chrome 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. The common ones are provided below.
+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.
 
 <details>
 <summary>Debian (e.g. Ubuntu) Dependencies</summary>
@@ -180,6 +189,21 @@ or `.zshenv`:
 export CHROME_DEVEL_SANDBOX=/usr/local/sbin/chrome-devel-sandbox
 ```
 
+## Firefox
+
+### Firefox 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.
+
+## 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.
+
+## Running Playwright on CI
 
 ### Running Playwright on Travis CI
 
@@ -217,6 +241,8 @@ before_install:
 
 ### Running Playwright on CircleCI
 
+> 👋 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.
+
 Running Playwright smoothly on CircleCI requires the following steps:
 
 1. Start with a [NodeJS
@@ -277,11 +303,11 @@ treatment for processes with PID=1, which makes it hard to terminate Chrome
 properly in some cases (e.g. in Docker).
 
 
-## Code Transpilation Issues
+## Code transpilation issues
 
 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 ecma version (`"target": "es2018"`). Another workaround could be using string templates instead of functions:
+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:
 
 ```js
 await page.evaluate(`(async() => {
@@ -289,9 +315,11 @@ await page.evaluate(`(async() => {
 })()`);
 ```
 
-## ReferenceError: URL is not defined
+## Node requirements
 
-Playwright requires node 10 or higher. Node 8 is not supported, and will cause you to receive this error.
+### ReferenceError: URL is not defined
+
+Playwright requires Node 10 or higher. Node 8 is not supported, and will cause you to receive this error.
 
 # Please file an issue