chore: automate prettier in docs (#7014)

Issue: #7012
Co-authored-by: Mathias Bynens <mathias@qiwi.be>

.prettierignore

@@ -0,0 +1,8 @@
+node_modules/
+lib/
+third_party/
+vendor/
+
+package-lock.json
+yarn.lock
+package.json

CONTRIBUTING.md

@@ -1,3 +1,4 @@
+<!-- prettier-ignore-start -->
 <!-- gen:toc -->
 - [How to Contribute](#how-to-contribute)
   * [Contributor License Agreement](#contributor-license-agreement)
@@ -21,7 +22,7 @@
     - [Bisecting upstream changes](#bisecting-upstream-changes)
   * [Releasing to npm](#releasing-to-npm)
 <!-- gen:stop -->
-
+<!-- prettier-ignore-end -->
 # How to Contribute
 
 First of all, thank you for your interest in Puppeteer!
@@ -164,6 +165,12 @@ To run the documentation linter, use:
 npm run doc
 ```
 
+To format the documentation markdown and its code snippets, use:
+
+```bash
+npm run markdownlint-fix
+```
+
 ## Adding New Dependencies
 
 For all dependencies (both installation and development):

docs/troubleshooting.md

@@ -1,5 +1,7 @@
 # Troubleshooting
 
+<!-- prettier-ignore-start -->
+
 <!-- GEN:toc -->
 - [Chrome headless doesn't launch on Windows](#chrome-headless-doesnt-launch-on-windows)
 - [Chrome headless doesn't launch on UNIX](#chrome-headless-doesnt-launch-on-unix)
@@ -21,6 +23,8 @@
 - [Code Transpilation Issues](#code-transpilation-issues)
 <!-- GEN:stop -->
 
+<!-- prettier-ignore-end -->
+
 ## Chrome headless doesn't launch on Windows
 
 Some [chrome policies](https://support.google.com/chrome/a/answer/7532015) might enforce running Chrome/Chromium
@@ -85,6 +89,7 @@ lsb-release
 wget
 xdg-utils
 ```
+
 </details>
 
 <details>
@@ -118,6 +123,7 @@ After installing dependencies you need to update nss library using this command
 ```
 yum update nss -y
 ```
+
 </details>
 
 <details>
@@ -139,7 +145,6 @@ spawn /Users/.../node_modules/puppeteer/.local-chromium/mac-756035/chrome-mac/Ch
 
 This means that the browser was downloaded but failed to be extracted correctly. The most common cause is a bug in Node.js v14.0.0 which broke `extract-zip`, the module Puppeteer uses to extract browser downloads into the right place. The bug was fixed in Node.js v14.1.0, so please make sure you're running that version or higher. Alternatively, if you cannot upgrade, you could downgrade to Node.js v12, but we recommend upgrading when possible.
 
-
 ## 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,
@@ -150,7 +155,9 @@ If you **absolutely trust** the content you open in Chrome, you can launch Chrom
 with the `--no-sandbox` argument:
 
 ```js
-const browser = await puppeteer.launch({args: ['--no-sandbox', '--disable-setuid-sandbox']});
+const browser = await puppeteer.launch({
+  args: ['--no-sandbox', '--disable-setuid-sandbox'],
+});
 ```
 
 > **NOTE**: Running without a sandbox is **strongly discouraged**. Consider configuring a sandbox instead.
@@ -191,12 +198,12 @@ or `.zshenv`:
 export CHROME_DEVEL_SANDBOX=/usr/local/sbin/chrome-devel-sandbox
 ```
 
-
 ## Running Puppeteer on Travis CI
 
 > 👋 We ran our tests for Puppeteer on Travis CI until v6.0.0 (when we've migrated to GitHub Actions) - see our historical [`.travis.yml` (v5.5.0)](https://github.com/puppeteer/puppeteer/blob/v5.5.0/.travis.yml) for reference.
 
 Tips-n-tricks:
+
 - [xvfb](https://en.wikipedia.org/wiki/Xvfb) service should be launched in order to run Chromium in non-headless mode
 - Runs on Xenial Linux on Travis by default
 - Runs `npm install` by default
@@ -366,7 +373,7 @@ longer necessary. Instead, launch the browser with the `--disable-dev-shm-usage`
 
 ```js
 const browser = await puppeteer.launch({
-  args: ['--disable-dev-shm-usage']
+  args: ['--disable-dev-shm-usage'],
 });
 ```
 
@@ -422,17 +429,17 @@ If you are using an EC2 instance running amazon-linux in your CI/CD pipeline, an
 
 1. To install Chromium, you have to first enable `amazon-linux-extras` which comes as part of [EPEL (Extra Packages for Enterprise Linux)](https://aws.amazon.com/premiumsupport/knowledge-center/ec2-enable-epel/):
 
-    ```sh
+   ```sh
-    sudo amazon-linux-extras install epel -y
+   sudo amazon-linux-extras install epel -y
-    ```
+   ```
 
 1. Next, install Chromium:
 
-    ```sh
+   ```sh
-    sudo yum install -y chromium
+   sudo yum install -y chromium
-    ```
+   ```
 
-Now Puppeteer can launch Chromium to run your tests. If you do not enable EPEL and if you continue installing chromium as part of `npm install`, Puppeteer cannot launch Chromium due to unavailablity of `libatk-1.0.so.0` and many more packages. 
+Now Puppeteer can launch Chromium to run your tests. If you do not enable EPEL and if you continue installing chromium as part of `npm install`, Puppeteer cannot launch Chromium due to unavailablity of `libatk-1.0.so.0` and many more packages.
 
 ## Code Transpilation Issues
 

examples/README.md

@@ -17,7 +17,7 @@ More complex and use case driven examples can be found at [github.com/GoogleChro
 ## Rendering and web scraping
 
 - [Puppetron](https://github.com/cheeaun/puppetron) - Demo site that shows how to use Puppeteer and Headless Chrome to render pages. Inspired by [GoogleChrome/rendertron](https://github.com/GoogleChrome/rendertron).
-- [Thal](https://medium.com/@e_mad_ehsan/getting-started-with-puppeteer-and-chrome-headless-for-web-scrapping-6bf5979dee3e "An article on medium") - Getting started with Puppeteer and Chrome Headless for Web Scraping.
+- [Thal](https://medium.com/@e_mad_ehsan/getting-started-with-puppeteer-and-chrome-headless-for-web-scrapping-6bf5979dee3e 'An article on medium') - Getting started with Puppeteer and Chrome Headless for Web Scraping.
 - [pupperender](https://github.com/LasaleFamine/pupperender) - Express middleware that checks the User-Agent header of incoming requests, and if it matches one of a configurable set of bots, render the page using Puppeteer. Useful for PWA rendering.
 - [headless-chrome-crawler](https://github.com/yujiosaka/headless-chrome-crawler) - Crawler that provides simple APIs to manipulate Headless Chrome and allows you to crawl dynamic websites.
 - [puppeteer-examples](https://github.com/checkly/puppeteer-examples) - Puppeteer Headless Chrome examples for real life use cases such as getting useful info from the web pages or common login scenarios.
@@ -35,4 +35,5 @@ More complex and use case driven examples can be found at [github.com/GoogleChro
 - [cucumber-puppeteer-example](https://github.com/mlampedx/cucumber-puppeteer-example) - Example repository demonstrating how to use Puppeeteer and Cucumber for integration testing.
 
 ## Services
+
 - [Checkly](https://checklyhq.com) - Monitoring SaaS that uses Puppeteer to check availability and correctness of web pages and apps.

experimental/puppeteer-firefox/README.md

@@ -21,7 +21,7 @@ Note: When you install puppeteer-firefox, it downloads a [custom-built Firefox](
 
 ### Usage
 
-**Example** - navigating to https://example.com and saving a screenshot as *example.png*:
+**Example** - navigating to https://example.com and saving a screenshot as `example.png`:
 
 Save file as **example.js**
 
@@ -32,7 +32,7 @@ const pptrFirefox = require('puppeteer-firefox');
   const browser = await pptrFirefox.launch();
   const page = await browser.newPage();
   await page.goto('https://example.com');
-  await page.screenshot({path: 'example.png'});
+  await page.screenshot({ path: 'example.png' });
   await browser.close();
 })();
 ```

package.json

@@ -24,7 +24,9 @@
     "eslint": "([ \"$CI\" = true ] && eslint --ext js --ext ts --quiet -f codeframe . || eslint --ext js --ext ts .)",
     "eslint-fix": "eslint --ext js --ext ts --fix .",
     "commitlint": "commitlint --from=HEAD~1",
-    "lint": "npm run eslint && npm run build && npm run doc && npm run commitlint",
+    "markdownlint": "prettier --check **/README.md docs/api.md docs/troubleshooting.md",
+    "markdownlint-fix": "prettier --write **/README.md docs/api.md docs/troubleshooting.md",
+    "lint": "npm run eslint && npm run build && npm run doc && npm run commitlint && npm run markdownlint",
     "doc": "node utils/doclint/cli.js",
     "clean-lib": "rm -rf lib",
     "build": "npm run tsc && npm run generate-d-ts",

test/README.md

@@ -4,19 +4,18 @@ Unit tests in Puppeteer are written using [Mocha] as the test runner and [Expect
 
 ## Test state
 
-
 We have some common setup that runs before each test and is defined in `mocha-utils.js`.
 
 You can use the `getTestState` function to read state. It exposes the following that you can use in your tests. These will be reset/tidied between tests automatically for you:
 
-* `puppeteer`: an instance of the Puppeteer library. This is exactly what you'd get if you ran `require('puppeteer')`.
+- `puppeteer`: an instance of the Puppeteer library. This is exactly what you'd get if you ran `require('puppeteer')`.
-* `puppeteerPath`: the path to the root source file for Puppeteer.
+- `puppeteerPath`: the path to the root source file for Puppeteer.
-* `defaultBrowserOptions`: the default options the Puppeteer browser is launched from in test mode, so tests can use them and override if required.
+- `defaultBrowserOptions`: the default options the Puppeteer browser is launched from in test mode, so tests can use them and override if required.
-* `server`: a dummy test server instance (see `utils/testserver` for more).
+- `server`: a dummy test server instance (see `utils/testserver` for more).
-* `httpsServer`: a dummy test server HTTPS instance (see `utils/testserver` for more).
+- `httpsServer`: a dummy test server HTTPS instance (see `utils/testserver` for more).
-* `isFirefox`: true if running in Firefox.
+- `isFirefox`: true if running in Firefox.
-* `isChrome`: true if running Chromium.
+- `isChrome`: true if running Chromium.
-* `isHeadless`: true if the test is in headless mode.
+- `isHeadless`: true if the test is in headless mode.
 
 If your test needs a browser instance, you can use the `setupTestBrowserHooks()` function which will automatically configure a browser that will be cleaned between each test suite run. You access this via `getTestState()`.
 
@@ -33,8 +32,8 @@ There is also `describeChromeOnly` and `itChromeOnly` which will only execute th
 There are also tests that assume a normal install flow, with browser binaries ending up in `.local-<browser>`, for example. Such tests are skipped with
 `itOnlyRegularInstall` which checks `BINARY` and `PUPPETEER_ALT_INSTALL` environment variables.
 
-[Mocha]: https://mochajs.org/
+[mocha]: https://mochajs.org/
-[Expect]: https://www.npmjs.com/package/expect
+[expect]: https://www.npmjs.com/package/expect
 
 ## Running tests
 
@@ -46,7 +45,7 @@ Despite being named 'unit', these are integration tests, making sure public API
 npm run unit
 ```
 
-- __Important__: don't forget to first run TypeScript if you're testing local changes:
+- **Important**: don't forget to first run TypeScript if you're testing local changes:
 
 ```bash
 npm run tsc && npm run unit
@@ -63,7 +62,7 @@ npm run tsc && npm run unit
   });
 ```
 
-- To disable a specific test, substitute the `it` with `xit` (mnemonic rule: '*cross it*'):
+- To disable a specific test, substitute the `it` with `xit` (mnemonic rule: '_cross it_'):
 
 ```js
   ...

utils/doclint/README.md

@@ -1,18 +1,14 @@
 # DocLint
 
-**Doclint** is a small program that lints Puppeteer's documentation against
+**Doclint** is a small program that lints Puppeteer's documentation against Puppeteer's source code.
-Puppeteer's source code.
 
 Doclint works in a few steps:
 
-1. Read sources in `lib/` folder, parse AST trees and extract public API
+1. Read sources in `lib/` folder, parse AST trees and extract public API. Note that we run DocLint on the outputted JavaScript in `lib/` rather than the source code in `src/`. We will do this until we have migrated `src/` to be exclusively TypeScript and then we can update DocLint to support TypeScript.
-    - note that we run DocLint on the outputted JavaScript in `lib/` rather than the source code in `src/`. We will do this until we have migrated `src/` to be exclusively TypeScript and then we can update DocLint to support TypeScript.
+2. Read sources in `docs/` folder, render markdown to HTML, use puppeteer to traverse the HTML and extract described API.
-2. Read sources in `docs/` folder, render markdown to HTML, use puppeteer to traverse the HTML
+3. Compare one API to another.
-  and extract described API
-3. Compare one API to another
 
-Doclint is also responsible for general markdown checks, most notably for the table of contents
+Doclint is also responsible for general markdown checks, most notably for the table of contents relevancy.
-relevancy.
 
 ## Running