### Installation and Basic Usage

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@isaacs/cliui/node_modules/ansi-styles/readme.md

Instructions on how to install the ansi-styles package and a basic example of its usage for styling text.

```APIDOC
## Installation

```sh
npm install ansi-styles
```

## Basic Usage

```js
import styles from 'ansi-styles';

console.log(`${styles.green.open}Hello world!${styles.green.close}`);
```
```

--------------------------------

### Yocto-Queue Installation and Usage

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/yocto-queue/readme.md

Instructions on how to install and basic usage examples for the yocto-queue package.

```APIDOC
## Installation

```bash
$ npm install yocto-queue
```

## Usage Example

```javascript
const Queue = require('yocto-queue');

const queue = new Queue();

queue.enqueue('item1');
queue.enqueue('item2');

console.log(queue.size); // Output: 2
console.log(...queue);   // Output: 'item1 item2'

console.log(queue.dequeue()); // Output: 'item1'
console.log(queue.dequeue()); // Output: 'item2'
```
```

--------------------------------

### Install verb and verb-generate-readme

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/is-extglob/README.md

Install the necessary tools globally to generate documentation. This is part of the project's development setup.

```sh
$ npm install -g verb verb-generate-readme && verb
```

--------------------------------

### Glob Installation and Basic Usage

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/glob/README.md

Instructions on how to install the glob library using npm and a basic example of its asynchronous usage.

```APIDOC
## Installation

Install with npm

```
npm i glob
```

## Basic Usage

```javascript
var glob = require("glob")

// options is optional
glob("**/*.js", options, function (er, files) {
  // files is an array of filenames.
  // If the `nonull` option is set, and nothing
  // was found, then files is ["**/*.js"]
  // er is an error object or null.
})
```
```

--------------------------------

### Hookified Setup

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/qified/node_modules/hookified/README.md

The base setup required for all Hookified examples. It involves importing Hookified, extending it, and instantiating the class.

```javascript
import { Hookified } from 'hookified';
class MyClass extends Hookified {
  constructor(options) { super(options); }
}
const myClass = new MyClass();
```

--------------------------------

### JSON5 Development Setup

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/json5/README.md

Clone the repository, install dependencies, and set up your development environment for contributing to JSON5.

```sh
git clone https://github.com/json5/json5
cd json5
npm install
```

--------------------------------

### Install and Use UAParser.js in Node.js

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/ua-parser-js/readme.md

Installation command and example of using the library within an HTTP server. Note that device information is unavailable in Node.js.

```sh
$ npm install ua-parser-js
```

```js
var http = require('http');
var parser = require('ua-parser-js');

http.createServer(function (req, res) {
    // get user-agent header
    var ua = parser(req.headers['user-agent']);
    // write the result as response
    res.end(JSON.stringify(ua, null, '  '));
})
.listen(1337, '127.0.0.1');

console.log('Server running at http://127.0.0.1:1337/');
```

--------------------------------

### End-to-End Example with Keyv and Redis

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/keyv/README.md

Demonstrates basic Keyv operations (set, get, delete, clear) using the Redis adapter. Shows setting values with and without expiration.

```javascript
import Keyv from 'keyv';
import KeyvRedis from '@keyv/redis';

const keyvRedis = new KeyvRedis('redis://user:pass@localhost:6379');
const keyv = new Keyv({ store: keyvRedis });

await keyv.set('foo', 'expires in 1 second', 1000); // true
await keyv.set('foo', 'never expires'); // true
await keyv.get('foo'); // 'never expires'
await keyv.delete('foo'); // true
await keyv.clear(); // undefined
```

--------------------------------

### Setup Standalone Proxy Server with Latency

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/http-proxy/README.md

This example shows how to introduce latency to proxied requests. It simulates a delay before forwarding the request to the target server. Requires 'http' and 'http-proxy' modules.

```javascript
var http = require('http'),
    httpProxy = require('http-proxy');

//
// Create a proxy server with latency
//
var proxy = httpProxy.createProxyServer();

//
// Create your server that makes an operation that waits a while
// and then proxies the request
//
http.createServer(function (req, res) {
  // This simulates an operation that takes 500ms to execute
  setTimeout(function () {
    proxy.web(req, res, {
      target: 'http://localhost:9008'
    });
  }, 500);
}).listen(8008);

//
// Create your target server
//
http.createServer(function (req, res) {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.write('request successfully proxied to: ' + req.url + '\n' + JSON.stringify(req.headers, true, 2));
  res.end();
}).listen(9008);
```

--------------------------------

### Install Keyv

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/flat-cache/node_modules/keyv/README.md

Install Keyv using npm. This command installs the core Keyv package.

```bash
npm install --save keyv
```

--------------------------------

### Basic Optionator Setup and Usage

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/eslint/node_modules/optionator/README.md

Demonstrates how to initialize Optionator with custom settings for options, prepend/append text, and then parse command-line arguments. Includes logic to display help if the 'help' option is present.

```javascript
var optionator = require('optionator')({
    prepend: 'Usage: cmd [options]',
    append: 'Version 1.0.0',
    options: [{ 
        option: 'help',
        alias: 'h',
        type: 'Boolean',
        description: 'displays help'
    }, { 
        option: 'count',
        alias: 'c',
        type: 'Int',
        description: 'number of things',
        example: 'cmd --count 2'
    }]
});

var options = optionator.parseArgv(process.argv);
if (options.help) {
    console.log(optionator.generateHelp());
}
...
```

--------------------------------

### Initialize a Connect Application

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/connect/README.md

A complete example demonstrating how to set up a Connect app with compression, session management, body parsing, and a basic response handler.

```javascript
var connect = require('connect');
var http = require('http');

var app = connect();

// gzip/deflate outgoing responses
var compression = require('compression');
app.use(compression());

// store session state in browser cookie
var cookieSession = require('cookie-session');
app.use(cookieSession({
    keys: ['secret1', 'secret2']
}));

// parse urlencoded request bodies into req.body
var bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({extended: false}));

// respond to all requests
app.use(function(req, res){
  res.end('Hello from Connect!\n');
});

//create node.js http server and listen on port
http.createServer(app).listen(3000);
```

--------------------------------

### Start Local Development Server

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/inspector_overlay/README.md

Command to initiate a local web server for testing overlay UI without bundling.

```bash
python -m SimpleHTTPServer 8000
```

--------------------------------

### Serve Documentation Locally

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/scripts/component_docs/README.md

Start a local HTTP server in the output directory to view the generated documentation.

```bash
python3 -m http.server 8000
```

--------------------------------

### Quickstart

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/micromatch/README.md

Basic usage examples for micromatch.

```APIDOC
## Quickstart

```js
const micromatch = require('micromatch');
// micromatch(list, patterns[, options]);
```

The [main export](#micromatch) takes a list of strings and one or more glob patterns:

```js
console.log(micromatch(['foo', 'bar', 'baz', 'qux'], ['f*', 'b*'])) //=> ['foo', 'bar', 'baz']
console.log(micromatch(['foo', 'bar', 'baz', 'qux'], ['*', '!b*'])) //=> ['foo', 'qux']
```

Use [.isMatch()](#ismatch) to for boolean matching:

```js
console.log(micromatch.isMatch('foo', 'f*')) //=> true
console.log(micromatch.isMatch('foo', ['b*', 'f*'])) //=> true
```

[Switching](#switching-to-micromatch) from minimatch and multimatch is easy!
```

--------------------------------

### Setup Basic Stand-alone Proxy Server

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/http-proxy/README.md

Set up a basic stand-alone proxy server by creating a proxy instance with a target and then invoking the `listen` method on the proxy instance. A target server is also created for demonstration.

```javascript
var http = require('http'),
    httpProxy = require('http-proxy');
//
// Create your proxy server and set the target in the options.
//
httpProxy.createProxyServer({target:'http://localhost:9000'}).listen(8000); // See (†)

//
// Create your target server
//
http.createServer(function (req, res) {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.write('request successfully proxied!' + '\n' + JSON.stringify(req.headers, true, 2));
  res.end();
}).listen(9000);
```

--------------------------------

### new Keyv([uri], [options])

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/flat-cache/node_modules/keyv/README.md

Initializes a new Keyv instance with optional connection URI and configuration settings.

```APIDOC
## new Keyv([uri], [options])

### Description
Returns a new Keyv instance. The instance is an EventEmitter that emits an 'error' event if the storage adapter connection fails.

### Parameters
#### Path Parameters
- **uri** (String) - Optional - The connection string URI.

#### Request Body
- **options** (Object) - Optional - Configuration object passed to the storage adapter.
- **options.namespace** (String) - Optional - Namespace for the current instance. Default: 'keyv'.
- **options.ttl** (Number) - Optional - Default Time-To-Live. Can be overridden on .set().

### Request Example
const keyv = new Keyv('redis://localhost', { namespace: 'my-app', ttl: 5000 });
```

--------------------------------

### Defining Commands with Options and Actions

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/commander/Readme.md

Define commands with descriptions, options, and associated actions. This snippet demonstrates setting up 'setup' and 'exec' commands, including aliases and custom help for commands.

```javascript
var program = require('commander');

program
  .version('0.1.0')
  .option('-C, --chdir <path>', 'change the working directory')
  .option('-c, --config <path>', 'set config path. defaults to ./deploy.conf')
  .option('-T, --no-tests', 'ignore test hook');

program
  .command('setup [env]')
  .description('run setup commands for all envs')
  .option("-s, --setup_mode [mode]", "Which setup mode to use")
  .action(function(env, options){
    var mode = options.setup_mode || "normal";
    env = env || 'all';
    console.log('setup for %s env(s) with %s mode', env, mode);
  });

program
  .command('exec <cmd>')
  .alias('ex')
  .description('execute the given remote cmd')
  .option("-e, --exec_mode <mode>", "Which exec mode to use")
  .action(function(cmd, options){
    console.log('exec "%s" using %s mode', cmd, options.exec_mode);
  }).on('--help', function() {
    console.log('');
    console.log('Examples:');
    console.log('');
    console.log('  $ deploy exec sequential');
    console.log('  $ deploy exec async');
  });

program
  .command('*')
  .action(function(env){
    console.log('deploying "%s"', env);
  });

program.parse(process.argv);

```

--------------------------------

### Deep Filter Example

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@nodelib/fs.walk/README.md

Provides an example of a `deepFilter` function that prevents the traversal from entering directories whose paths start with `node_modules`.

```typescript
// Skip all directories that starts with `node_modules`
const filter: DeepFilterFunction = (entry) => !entry.path.startsWith('node_modules');
```

--------------------------------

### Installation and Usage

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/eslint/node_modules/eslint-visitor-keys/README.md

Instructions on how to install and import the eslint-visitor-keys package into your project.

```APIDOC
## Installation

Use npm to install:

```bash
$ npm install eslint-visitor-keys
```

### Requirements

- Node.js `^18.18.0`, `^20.9.0`, or `>=21.1.0`

## Usage

To use in an ESM file:

```js
import * as evk from "eslint-visitor-keys"
```

To use in a CommonJS file:

```js
const evk = require("eslint-visitor-keys")
```
```

--------------------------------

### Installation via NPM

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/fast-json-stable-stringify/README.md

Command to install the package.

```bash
npm install fast-json-stable-stringify
```

--------------------------------

### Install and Run NPM License Checker

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/license-checker/README.md

Install the license-checker globally and run it on a project to see dependency licenses. This is a basic setup for initial use.

```shell
npm install -g license-checker

mkdir foo
cd foo
npm install yui-lint
license-checker
```

--------------------------------

### Version Option Example

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/svgo/node_modules/commander/Readme.md

Example of how the version option is displayed when invoked.

```bash
$ ./examples/pizza -V
0.0.1
```

--------------------------------

### Usage in Node.js

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/treeify/README.md

Example of how to use the `asTree` method in a Node.js project after installation.

```APIDOC
## Usage in Node.js

Then proceed to use it in your project:
```javascript
var treeify = require('treeify');
console.log(
   treeify.asTree({
      apples: 'gala',      //  ├─ apples: gala
      oranges: 'mandarin'  //  └─ oranges: mandarin
   }, true)
);
```
```

--------------------------------

### Initialize Engine.IO Client

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/engine.io/README.md

Shows how to include the client library and establish a connection to the server.

```html
<script src="/path/to/engine.io.js"></script>
<script>
  const socket = new eio.Socket('ws://localhost/');
  socket.on('open', () => {
    socket.on('message', data => {});
    socket.on('close', () => {});
  });
</script>
```

--------------------------------

### Install on-finished

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/body-parser/node_modules/on-finished/README.md

Use npm to install the module in your project.

```sh
$ npm install on-finished
```

--------------------------------

### Get Executable Path

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/bare-os/README.md

Returns the absolute path of the executable that started the process.

```javascript
const p = os.execPath()
```

--------------------------------

### Quick Start: Get MIME Type and Extension

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/mime/README.md

Basic usage of the Mime module to get the MIME type from an extension and the extension from a MIME type. This demonstrates the core functionality.

```javascript
const mime = require('mime');

mime.getType('txt');                    // ⇨ 'text/plain'
mime.getExtension('text/plain');        // ⇨ 'txt'
```

--------------------------------

### Build Component Documentation

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/scripts/component_docs/README.md

Execute this command to build the component documentation, generating an `index.html` file in the output directory.

```bash
autoninja -C out/Default scripts/component_docs
```

--------------------------------

### Get unquoted attribute value

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/postcss-selector-parser/API.md

Examples of retrieving the raw unquoted content from an attribute value.

```css
[href=foo] /* foo */
[href='foo'] /* foo */
[href="foo"] /* foo */
[href] /* undefined */
```

--------------------------------

### Run Example Code

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/svg-tags/README.md

Execute the example JavaScript file using Node.js from the top-level application directory.

```bash
$ node ./examples/index.js
```

--------------------------------

### Installation

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/color-convert/README.md

Instructions on how to install the color-convert library using npm.

```APIDOC
## Install

### Description
Instructions on how to install the color-convert library using npm.

### Request Example
```console
$ npm install color-convert
```
```

--------------------------------

### Streamroller Usage and Constructor

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/streamroller/README.md

This section covers the basic installation, usage example, and the constructor for creating a RollingFileStream.

```APIDOC
## Installation
```sh
npm install streamroller
```

## Usage Example
```javascript
var rollers = require('streamroller');
var stream = new rollers.RollingFileStream('myfile', 1024, 3);
stream.write("stuff");
stream.end();
```

## Constructor: RollingFileStream

This returns a `WritableStream` that manages file rollovers.

### Parameters

*   **filename** (string) - The base name for the log file.
*   **maxSize** (integer) - Optional. Defaults to `MAX_SAFE_INTEGER`. The size in bytes that triggers a rollover.
*   **numBackups** (integer) - Optional. Defaults to `1`. The number of old files to keep (excluding the current active file).
*   **options** (Object) - Optional. Configuration options for the stream.
    *   **encoding** (string) - Optional. Defaults to `'utf8'`. The encoding for the file.
    *   **mode** (integer) - Optional. Defaults to `0o600`. The file mode (see [node.js file modes](https://nodejs.org/dist/latest-v12.x/docs/api/fs.html#fs_file_modes)).
    *   **flags** (string) - Optional. Defaults to `'a'`. The file system flags (see [node.js file flags](https://nodejs.org/dist/latest-v12.x/docs/api/fs.html#fs_file_system_flags)).
    *   **compress** (boolean) - Optional. Defaults to `false`. If true, backup files will be compressed using gzip and have a `.gz` extension.
    *   **keepFileExt** (boolean) - Optional. Defaults to `false`. If true, preserves the file extension when rotating log files (e.g., `file.log` becomes `file.1.log` instead of `file.log.1`).
    *   **fileNameSep** (string) - Optional. Defaults to `'.'`. The separator used when naming backup files (e.g., `abc.log.1` or `abc.1.log` if `keepFileExt` is true).

### Rollover Behavior

When the current file being written to reaches or exceeds `maxSize`, the following occurs:

1.  The current file is renamed to `filename.1`.
2.  A new file is created for writing.

Up to `numBackups` old files are maintained. For example, if `numBackups` is 3, the files will be named:

```
     filename
     filename.1
     filename.2
     filename.3
```

When `filename` size >= `maxSize`:

```
     filename     -> filename.1
     filename.1   -> filename.2
     filename.2   -> filename.3
     filename.3   gets overwritten
     filename     is a new file
```
```

--------------------------------

### Basic Usage Example

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/meow/readme.md

Demonstrates how to use the meow CLI helper with arguments and flags.

```sh
./foo-app.js unicorns --rainbow
```

```js
#!/usr/bin/env node
import meow from 'meow';
import foo from './lib/index.js';

const cli = meow(`
	Usage
	  $ foo <input>

	Options
	  --rainbow, -r  Include a rainbow

	Examples
	  $ foo unicorns --rainbow
	  🌈 unicorns 🌈
`, {
		importMeta: import.meta,
		flags: {
			rainbow: {
				type: 'boolean',
				shortFlag: 'r'
			}
		}
	});
/*
{
	input: ['unicorns'],
	flags: {rainbow: true},
	...
}
*/

foo(cli.input.at(0), cli.flags);
```

--------------------------------

### Initialize Keyv Instance

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/flat-cache/node_modules/keyv/README.md

Create a new Keyv instance. Pass a connection string to automatically load the correct storage adapter. Handle database connection errors using the 'error' event.

```javascript
const Keyv = require('keyv');

// One of the following
const keyv = new Keyv();
const keyv = new Keyv('redis://user:pass@localhost:6379');
const keyv = new Keyv('mongodb://user:pass@localhost:27017/dbname');
const keyv = new Keyv('sqlite://path/to/database.sqlite');
const keyv = new Keyv('postgresql://user:pass@localhost:5432/dbname');
const keyv = new Keyv('mysql://user:pass@localhost:3306/dbname');
const keyv = new Keyv('etcd://localhost:2379');

// Handle DB connection errors
keyv.on('error', err => console.log('Connection Error', err));
```

--------------------------------

### Clean Project Dependencies

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/flat-cache/node_modules/keyv/README.md

Removes Yarn and all installed dependencies. After running, you must repeat the setup steps.

```bash
yarn clean
```

--------------------------------

### Use side-channel-map

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/side-channel-map/README.md

Basic usage example demonstrating setting, getting, asserting, and deleting values in the side channel.

```js
const assert = require('assert');
const getSideChannelMap = require('side-channel-map');

const channel = getSideChannelMap();

const key = {};
assert.equal(channel.has(key), false);
assert.throws(() => channel.assert(key), TypeError);

channel.set(key, 42);

channel.assert(key); // does not throw
assert.equal(channel.has(key), true);
assert.equal(channel.get(key), 42);

channel.delete(key);
assert.equal(channel.has(key), false);
assert.throws(() => channel.assert(key), TypeError);
```

--------------------------------

### GET /products/:id

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/cors/README.md

An example endpoint demonstrating how to implement asynchronous CORS configuration using a whitelist delegate.

```APIDOC
## GET /products/:id

### Description
Retrieves product information with CORS enabled based on a dynamic whitelist check.

### Method
GET

### Endpoint
/products/:id

### Parameters
#### Path Parameters
- **id** (string) - Required - The unique identifier of the product.

### Response
#### Success Response (200)
- **msg** (string) - Confirmation message indicating CORS is enabled for the domain.

#### Response Example
{
  "msg": "This is CORS-enabled for a whitelisted domain."
}
```

--------------------------------

### Installation

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@typescript-eslint/visitor-keys/node_modules/eslint-visitor-keys/README.md

Instructions on how to install the eslint-visitor-keys package using npm.

```APIDOC
## Installation

Use [npm] to install.

```bash
$ npm install eslint-visitor-keys
```

### Requirements

- [Node.js] `^20.19.0`, `^22.13.0`, or `>=24`
```

--------------------------------

### Example package.json structure

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/eslint-plugin-import/docs/rules/no-extraneous-dependencies.md

A sample package.json file demonstrating various dependency categories.

```json
{
  "name": "my-project",
  "...": "...",
  "dependencies": {
    "builtin-modules": "^1.1.1",
    "lodash.cond": "^4.2.0",
    "lodash.find": "^4.2.0",
    "pkg-up": "^1.0.0"
  },
  "devDependencies": {
    "ava": "^0.13.0",
    "eslint": "^2.4.0",
    "eslint-plugin-ava": "^1.3.0",
    "xo": "^0.13.0"
  },
  "optionalDependencies": {
    "lodash.isarray": "^4.0.0"
  },
  "peerDependencies": {
    "react": ">=15.0.0 <16.0.0"
  },
  "bundledDependencies": [
    "@generated/foo",
  ]
}
```

--------------------------------

### Install Mocha Type Definitions

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@types/mocha/README.md

Use npm to install the @types/mocha package, which provides TypeScript type definitions for the Mocha testing framework. This is useful for projects using TypeScript to get better autocompletion and type checking when writing tests.

```bash
npm install --save @types/mocha
```

--------------------------------

### Run DevTools with Canary Browser

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/front_end/models/ai_assistance/README.md

Starts the DevTools development server using the Canary browser. Ensure you have Canary installed and configured.

```bash
npm start -- --browser=canary
```

--------------------------------

### Build and test the project

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/fast-levenshtein/README.md

Commands to install dependencies and run the build process.

```bash
$ npm install -g grunt-cli
$ npm install
$ npm run build
```

--------------------------------

### Get Caller File in a Module

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/get-caller-file/README.md

This example demonstrates how to use the get-caller-file utility within a Node.js module to determine the invoking file.

```javascript
// ./foo.js
const getCallerFile = require('get-caller-file');

module.exports = function() {
  return getCallerFile(); // figures out who called it
};
```

--------------------------------

### Usage Example for @jridgewell/set-array

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@jridgewell/set-array/README.md

Demonstrates how to import and use SetArray, put, get, and pop functions. Ensure you have assert imported for the assertions to work.

```js
import { SetArray, get, put, pop } from '@jridgewell/set-array';

const sa = new SetArray();

let index = put(sa, 'first');
assert.strictEqual(index, 0);

index = put(sa, 'second');
assert.strictEqual(index, 1);

assert.deepEqual(sa.array, [ 'first', 'second' ]);

index = get(sa, 'first');
assert.strictEqual(index, 0);

pop(sa);
index = get(sa, 'second');
assert.strictEqual(index, undefined);
assert.deepEqual(sa.array, [ 'first' ]);
```

--------------------------------

### new Keyv([storage-adapter], [options]) or new Keyv([options])

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/keyv/README.md

Instantiates a new Keyv instance. You can optionally provide a storage adapter and/or configuration options.

```APIDOC
## new Keyv([storage-adapter], [options]) or new Keyv([options])

### Description
Instantiates a new Keyv instance. You can optionally provide a storage adapter and/or configuration options.

### Parameters
#### Path Parameters
- **storage-adapter** (object) - Optional - The storage adapter to use.
- **options** (object) - Optional - Configuration options for Keyv.
  - **namespace** (string) - Optional - A namespace for the storage.
  - **ttl** (number) - Optional - Default time-to-live in milliseconds.
  - **serialize** (function) - Optional - Custom serializer function.
  - **deserialize** (function) - Optional - Custom deserializer function.
  - **compression** (boolean|object) - Optional - Enable or configure compression.
  - **useKeyPrefix** (boolean) - Optional - Use key prefix for storage adapter.
  - **retry** (object) - Optional - Retry options for storage adapter operations.
  - **max** (number) - Optional - Maximum number of items in the cache (for memory adapter).
  - **ttlInterval** (number) - Optional - Interval for cleaning expired items (for memory adapter).
  - **store** (object) - Optional - The underlying storage instance.
```

--------------------------------

### Async Usage Example

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/escalade/readme.md

Demonstrates how to use the asynchronous version of escalade to find a 'package.json' file starting from a given input path. The callback logs the current directory and names, and returns the filename when found. Also shows an example of searching for a non-existent file.

```javascript
//~> demo.js
import { join } from 'path';
import escalade from 'escalade';

const input = join(__dirname, 'demo.js');
// or: const input = __dirname;

const pkg = await escalade(input, (dir, names) => {
  console.log('~> dir:', dir);
  console.log('~> names:', names);
  console.log('---');

  if (names.includes('package.json')) {
    // will be resolved into absolute
    return 'package.json';
  }
});

//~> dir: /Users/lukeed/oss/escalade/test/fixtures/foobar
//~> names: ['demo.js']
//---
//~> dir: /Users/lukeed/oss/escalade/test/fixtures
//~> names: ['index.js', 'foobar']
//---
//~> dir: /Users/lukeed/oss/escalade/test
//~> names: ['fixtures']
//---
//~> dir: /Users/lukeed/oss/escalade
//~> names: ['package.json', 'test']
//---

console.log(pkg);
//=> /Users/lukeed/oss/escalade/package.json

// Now search for "missing123.txt"
// (Assume it doesn't exist anywhere!)
const missing = await escalade(input, (dir, names) => {
  console.log('~> dir:', dir);
  return names.includes('missing123.txt') && 'missing123.txt';
});

//~> dir: /Users/lukeed/oss/escalade/test/fixtures/foobar
//~> dir: /Users/lukeed/oss/escalade/test/fixtures
//~> dir: /Users/lukeed/oss/escalade/test
//~> dir: /Users/lukeed/oss/escalade
//~> dir: /Users/lukeed/oss
//~> dir: /Users/lukeed
//~> dir: /Users
//~> dir: /

console.log(missing);
//=> undefined

```

--------------------------------

### Build and Update Documentation

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/front_end/third_party/third-party-web/package/lib/markdown/template.md

Commands to install dependencies, build the project, and regenerate the README.

```bash
# Install `cairo` and dependencies for node-canvas
brew install pkg-config cairo pango libpng jpeg giflib
# Build the requirements in this repo
yarn build
# Regenerate the README
yarn start
```

--------------------------------

### Install with Custom Source Map Retrieval

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/source-map-support/README.md

Provide a `retrieveSourceMap` callback to customize how source maps are loaded. This example shows caching source maps in memory.

```javascript
require('source-map-support').install({
  retrieveSourceMap: function(source) {
    if (source === 'compiled.js') {
      return {
        url: 'original.js',
        map: fs.readFileSync('compiled.js.map', 'utf8')
      };
    }
    return null;
  }
});
```

--------------------------------

### Get Symbol Description Example

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/get-symbol-description/README.md

Import and use the `get-symbol-description` function to test its behavior with different Symbol types. Asserts are used to verify the expected output.

```javascript
var getSymbolDescription = require('get-symbol-description');
var assert = require('assert');

assert(getSymbolDescription(Symbol()) === undefined);
assert(getSymbolDescription(Symbol('')) === ''); // or `undefined`, if in an engine that lacks name inference from concise method
assert(getSymbolDescription(Symbol('foo')) === 'foo');
assert(getSymbolDescription(Symbol.iterator) === 'Symbol.iterator');
```

--------------------------------

### Usage Example for side-channel-list

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/side-channel-list/README.md

Demonstrates basic usage of the side-channel-list, including setting, getting, asserting, and deleting keys. Ensure keys are deleted to prevent memory leaks.

```js
const assert = require('assert');
const getSideChannelList = require('side-channel-list');

const channel = getSideChannelList();

const key = {};
assert.equal(channel.has(key), false);
assert.throws(() => channel.assert(key), TypeError);

channel.set(key, 42);

channel.assert(key); // does not throw
assert.equal(channel.has(key), true);
assert.equal(channel.get(key), 42);

channel.delete(key);
assert.equal(channel.has(key), false);
assert.throws(() => channel.assert(key), TypeError);
```

--------------------------------

### Basic Mitt Usage Example

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/mitt/README.md

Demonstrates how to create an emitter instance, listen to events (including wildcard), emit events, clear all handlers, and manage handler references for listening and unlistening.

```javascript
import mitt from 'mitt'

const emitter = mitt()

// listen to an event
emitter.on('foo', e => console.log('foo', e) )

// listen to all events
emitter.on('*', (type, e) => console.log(type, e) )

// fire an event
emitter.emit('foo', { a: 'b' })

// clearing all events
emitter.all.clear()

// working with handler references:
function onFoo() {}
emitter.on('foo', onFoo)   // listen
emitter.off('foo', onFoo)  // unlisten
```

--------------------------------

### Access browser globals

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@eslint/eslintrc/node_modules/globals/readme.md

Import the 'globals' package and access the 'browser' property to get a list of browser-specific global identifiers. The output shows examples of these globals and their read-only status.

```js
const globals = require('globals');

console.log(globals.browser);
/*
{
	addEventListener: false,
	applicationCache: false,
	ArrayBuffer: false,
	atob: false,
	…
}
*/
```

--------------------------------

### Install Dependencies

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/engine.io-parser/Readme.md

Commands to navigate to the directory and install dependencies.

```bash
cd engine.io-parser
npm ci
```

--------------------------------

### Get and Validate Typed Array Names

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/possible-typed-array-names/README.md

Use this snippet to retrieve the list of Typed Array names and assert their validity. Ensure the 'assert' module is available and the 'possible-typed-array-names' package is installed.

```javascript
const assert = require('assert');

const names = require('possible-typed-array-names');

assert(Array.isArray(names));
assert(names.every(name => (
    typeof name === 'string'
    && typeof globalThis[name] === 'function'
    && globalThis[name].name === name
)));
```

--------------------------------

### Step Option Examples

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/fill-range/README.md

Demonstration of the step option with numbers and letters.

```js
// numbers
console.log(fill('1', '10', 2)); //=> [ '1', '3', '5', '7', '9' ]
console.log(fill('1', '10', 3)); //=> [ '1', '4', '7', '10' ]
console.log(fill('1', '10', 4)); //=> [ '1', '5', '9' ]

// letters
console.log(fill('a', 'z', 5)); //=> [ 'a', 'f', 'k', 'p', 'u', 'z' ]
console.log(fill('a', 'z', 7)); //=> [ 'a', 'h', 'o', 'v' ]
console.log(fill('a', 'z', 9)); //=> [ 'a', 'j', 's' ]
```

--------------------------------

### Generate Browserslist Query from Electron Major Version (Deprecated)

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/electron-to-chromium/README.md

Use the deprecated `electronToBrowserList` function with a major Electron version to get a Browserslist query string. Example uses '1.4'.

```javascript
var query = e2c.electronToBrowserList('1.4');
// query is "Chrome >= 53"
```

--------------------------------

### Convert Chromium Major Version to Electron Major Version

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/electron-to-chromium/README.md

Use the `chromiumToElectron` function with a major Chromium version to get the corresponding major Electron version. Example uses '54'.

```javascript
var electronVersion = e2c.chromiumToElectron('54');
// electronVersion is "1.4"
```

--------------------------------

### Install bare-os

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/bare-os/README.md

Install the bare-os module using npm.

```bash
npm i bare-os
```

--------------------------------

### Install source map support programmatically

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/source-map-support/README.md

Invoke the install method at the top of your entry file.

```javascript
require('source-map-support').install();
```

--------------------------------

### Convert Electron Full Version to Chromium Full Version

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/electron-to-chromium/README.md

Use the `electronToChromium` function with a full Electron version to get the corresponding full Chromium version. Example uses '1.4.11'.

```javascript
var chromeVersion = e2c.electronToChromium('1.4.11');
// chromeVersion is "53.0.2785.143"
```

--------------------------------

### Convert Electron Major Version to Chromium Major Version

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/electron-to-chromium/README.md

Use the `electronToChromium` function with a major Electron version to get the corresponding major Chromium version. Example uses '1.4'.

```javascript
var chromeVersion = e2c.electronToChromium('1.4');
// chromeVersion is "53"
```

--------------------------------

### Install Dependencies and Run Tests

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/fill-range/README.md

This command installs the necessary project dependencies and executes the unit tests. It's a standard way to verify the project's functionality.

```sh
$ npm install && npm test
```

--------------------------------

### Create Keyv Instance with BigMap Adapter

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@keyv/bigmap/README.md

Basic usage of createKeyv to initialize a Keyv instance with BigMap as the storage adapter. Includes examples for set, get, has, delete, and clear operations.

```typescript
import { createKeyv } from '@keyv/bigmap';

// Basic usage
const keyv = createKeyv();

// Set with TTL (in milliseconds)
await keyv.set('user:123', { name: 'Alice', age: 30 }, 60000); // Expires in 60 seconds

// Get value
const user = await keyv.get('user:123');
console.log(user); // { name: 'Alice', age: 30 }

// Check if key exists
const exists = await keyv.has('user:123');

// Delete key
await keyv.delete('user:123');

// Clear all keys
await keyv.clear();
```

--------------------------------

### Install to-regex-range

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/to-regex-range/README.md

Command to install the library via npm.

```sh
$ npm install --save to-regex-range
```

--------------------------------

### Install @eslint/config-helpers

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@eslint/config-helpers/README.md

Install the package using npm, yarn, pnpm, or bun for Node.js environments. For Deno, use the 'deno add' command.

```shell
npm install @eslint/config-helpers
```

```shell
yarn add @eslint/config-helpers
```

```shell
pnpm install @eslint/config-helpers
```

```shell
bun add @eslint/config-helpers
```

```shell
deno add @eslint/config-helpers
```

--------------------------------

### Example Output: Process Arguments

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/yargs-parser/README.md

Example of the output when parsing process arguments with '--foo=33 --bar hello'.

```console
$ node example.js --foo=33 --bar hello
{ _: [], foo: 33, bar: 'hello' }
```

--------------------------------

### Convert Chromium Full Version to Electron Full Versions

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/electron-to-chromium/README.md

Use the `chromiumToElectron` function with a full Chromium version to get an array of corresponding full Electron versions. Example uses '56.0.2924.87'.

```javascript
var electronVersions = e2c.chromiumToElectron('56.0.2924.87');
// electronVersions is ["1.6.3", "1.6.2", "1.6.1", "1.6.0"]
```

--------------------------------

### Setup Automatic Workspace Folders with Serve

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/docs/ecosystem/automatic_workspace_folders.md

This bash script sets up the necessary directory and configuration file for automatic workspace folders and starts a local server. It dynamically generates a UUID for the project.

```bash
cd /Users/foo/bar
mkdir -p .well-known/appspecific
echo "{\"workspace\":{\"root\":\"${PWD}\",\"uuid\":\"
$(npx --package uuid uuid v4)\"}}" > .well-known/appspecific/com.chrome.devtools.json
npx serve
```

--------------------------------

### Get Visitor Keys for an AST Node

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@stylistic/eslint-plugin/node_modules/eslint-visitor-keys/README.md

Retrieve the visitor keys for a given AST node. This utility excludes keys like 'parent', 'leadingComments', 'trailingComments', and properties starting with '_'. It's useful for traversing unknown nodes.

```javascript
const node = {
    type: "AssignmentExpression",
    left: { type: "Identifier", name: "foo" },
    right: { type: "Literal", value: 0 }
}
console.log(evk.getKeys(node)) // → ["type", "left", "right"]
```

--------------------------------

### Installing the plugin

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@web/rollup-plugin-import-meta-assets/README.md

Command to install the package as a development dependency.

```bash
npm install @web/rollup-plugin-import-meta-assets --save-dev
```

--------------------------------

### Compile and Run CoffeeScript with Source Maps

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/source-map-support/README.md

Install necessary packages, compile the CoffeeScript file with source map support, and run the generated JavaScript file. This setup helps in debugging by providing accurate error locations.

```sh
$ npm install source-map-support coffeescript
$ node_modules/.bin/coffee --map --compile demo.coffee
$ node demo.js
```

--------------------------------

### Command Line Usage Examples

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/nopt/README.md

Demonstrates various command-line invocations and their resulting parsed output objects.

```console
$ node my-program.js --foo "blerp" --no-flag
{ "foo" : "blerp", "flag" : false }

$ node my-program.js ---bar 7 --foo "Mr. Hand" --flag
{ bar: 7, foo: "Mr. Hand", flag: true }

$ node my-program.js --foo "blerp" -f -----p
{ foo: "blerp", flag: true, pick: true }

$ node my-program.js -fp --foofoo
{ foo: "Mr. Foo", flag: true, pick: true }

$ node my-program.js --foofoo -- -fp  # -- stops the flag parsing.
{ foo: "Mr. Foo", argv: { remain: ["-fp"] } }

$ node my-program.js --blatzk -fp # unknown opts are ok.
{ blatzk: true, flag: true, pick: true }

$ node my-program.js --blatzk=1000 -fp # but you need to use = if they have a value
{ blatzk: 1000, flag: true, pick: true }

$ node my-program.js --no-blatzk -fp # unless they start with "no-"
{ blatzk: false, flag: true, pick: true }

$ node my-program.js --baz b/a/z # known paths are resolved.
{ baz: "/Users/isaacs/b/a/z" }

# if Array is one of the types, then it can take many
# values, and will always be an array.  The other types provided
# specify what types are allowed in the list.

$ node my-program.js --many1 5 --many1 null --many1 foo
{ many1: ["5", "null", "foo"] }

$ node my-program.js --many2 foo --many2 bar
{ many2: ["/path/to/foo", "path/to/bar"] }
```

--------------------------------

### Basic qjobs Usage Example

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/qjobs/Readme.md

Demonstrates how to initialize qjobs, add jobs, and handle various queue events like start, end, jobStart, jobEnd, pause, and unpause. Jobs can be added dynamically, and the queue can be paused and resumed.

```javascript
var qjobs = new require('./qjobs');
                                
// My non blocking main job     
var myjob = function(args,next) {
    setTimeout(function() {
        console.log('Do something interesting here',args);
        next();
    },1000);
}

var q = new qjobs({maxConcurrency:10});

// Let's add 30 job to the queue
for (var i = 0; i<30; i++) {
    q.add(myjob,[i,'test '+i]);
}

q.on('start',function() {
    console.log('Starting ...');
});

q.on('end',function() {
    console.log('... All jobs done');
});

q.on('jobStart',function(args) {
    console.log('jobStart',args);
});

q.on('jobEnd',function(args) {

    console.log('jobend',args);

    // If i'm jobId 10, then make a pause of 5 sec

    if (args._jobId == 10) {
        q.pause(true);
        setTimeout(function() {
            q.pause(false);
        },5000);
    }
});

q.on('pause',function(since) {
    console.log('in pause since '+since+' milliseconds');
});

q.on('unpause',function() {
    console.log('pause end, continu ..');
});

q.run();

//q.abort() will empty jobs list

```

--------------------------------

### Setup Standalone Proxy Server with Request Header Rewriting

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/http-proxy/README.md

This example demonstrates how to proxy requests while modifying outgoing proxy request headers. It uses the 'proxyReq' event to add a custom header before the request is sent to the target. Requires 'http' and 'http-proxy' modules.

```javascript
var http = require('http'),
    httpProxy = require('http-proxy');

//
// Create a proxy server with custom application logic
//
var proxy = httpProxy.createProxyServer({});

// To modify the proxy connection before data is sent, you can listen
// for the 'proxyReq' event. When the event is fired, you will receive
// the following arguments: (http.ClientRequest proxyReq, http.IncomingMessage req,
//  http.ServerResponse res, Object options). This mechanism is useful when
// you need to modify the proxy request before the proxy connection
// is made to the target.
//
proxy.on('proxyReq', function(proxyReq, req, res, options) {
  proxyReq.setHeader('X-Special-Proxy-Header', 'foobar');
});

var server = http.createServer(function(req, res) {
  // You can define here your custom logic to handle the request
  // and then proxy the request.
  proxy.web(req, res, {
    target: 'http://127.0.0.1:5050'
  });
});

console.log("listening on port 5050")
server.listen(5050);
```

--------------------------------

### Install Keyv Storage Adapters

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/keyv/README.md

Install optional storage adapters for Keyv, such as Redis, MongoDB, SQLite, and others.

```bash
npm install --save @keyv/redis
npm install --save @keyv/valkey
npm install --save @keyv/mongo
npm install --save @keyv/sqlite
npm install --save @keyv/postgres
npm install --save @keyv/mysql
npm install --save @keyv/etcd
npm install --save @keyv/memcache
npm install --save @keyv/dynamo
```

--------------------------------

### Basic Usage Example

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/@isaacs/cliui/README.md

Demonstrates how to use cliui to create a simple command-line interface with usage information and options.

```APIDOC
## Basic Usage Example

### Description
This example shows how to initialize cliui and add rows with text and formatting.

### Method
`require('cliui')()`

### Endpoint
N/A (Client-side library)

### Request Example
```javascript
const ui = require('cliui')()

ui.div('Usage: $0 [command] [options]')

ui.div({
  text: 'Options:',
  padding: [2, 0, 1, 0]
})

ui.div(
  {
    text: "-f, --file",
    width: 20,
    padding: [0, 4, 0, 4]
  },
  {
    text: "the file to load." +
      chalk.green("(if this description is long it wraps).")
    ,
    width: 20
  },
  {
    text: chalk.red("[required]"),
    align: 'right'
  }
)

console.log(ui.toString())
```

### Response
#### Success Response (200)
Outputs the formatted command-line interface to the console.

#### Response Example
```shell
Usage: $0 [command] [options]

Options:
-f, --file          the file to load. (if this description is long it wraps).     [required]
```
```

--------------------------------

### Install ESLint JSDoc Plugin

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/eslint-plugin-jsdoc/README.md

Install the eslint-plugin-jsdoc. Install globally if ESLint is global, otherwise install locally.

```sh
npm install --save-dev eslint-plugin-jsdoc
```

--------------------------------

### Install get-proto

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/get-proto/README.md

Use npm to install the package as a dependency.

```sh
npm install --save get-proto
```

--------------------------------

### Install and Configure ESLint

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/eslint/README.md

Use this command to install and configure ESLint for your project. Ensure you have Node.js installed.

```shell
npm init @eslint/config@latest
```

--------------------------------

### Install Storage Adapters

Source: https://github.com/chromedevtools/devtools-frontend/blob/main/node_modules/flat-cache/node_modules/keyv/README.md

Install optional storage adapters for Keyv, such as Redis, MongoDB, SQLite, PostgreSQL, MySQL, and Etcd.

```bash
npm install --save @keyv/redis
npm install --save @keyv/mongo
npm install --save @keyv/sqlite
npm install --save @keyv/postgres
npm install --save @keyv/mysql
npm install --save @keyv/etcd
```