Paul Irish paulirish

## coverage.js
'use strict';

const chromeLauncher = require('chrome-launcher');
const CDP = require('chrome-remote-interface');

const launchChrome = () =>
  chromeLauncher.launch({
    chromeFlags: ['--disable-gpu', '--headless']
  });

## server-timing-demo.js
// see for screenshot:
//     https://twitter.com/paul_irish/status/829090506084749312

const http = require('http');

function requestHandler(request, response) {
	const headers = {
		'Server-Timing': `
		  sql-1;desc="MySQL lookup Server";dur=100,
		  sql-2;dur=900;desc="MySQL shard Server #1",

## intro-overhead-of-performance.mark.md

      
              3 files
            
          
              3 forks
            
          
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              29 stars
            
          
                paulirish
                / intro-overhead-of-performance.mark.md
            
            
              Last active
              April 2, 2024 16:50
            
              
                Evaluating overhead of performance.mark()
              
          
    A few conversations have circled around user-side structural profiling. For context, see React PR #7549: Show React events in the timeline when ReactPerf is active
One particular concern is the measurement overhead. This gist has a benchmarking script (measure.js) for evaluating overhead and initial results.
Results: performance.mark()

Runs about 0.65µs per mark() call. Naturally, that's ~= an overhead of 1ms for 1500 mark()s.


## devtools-protocol-send-command-and-monitor.md

      
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              8 stars
            
          
                paulirish
                / devtools-protocol-send-command-and-monitor.md
            
            
              Last active
              February 11, 2020 17:42
                — forked from jasonLaster/inspector.js
            
              
                how to issue commands and monitor the devtools protocol
              
          
    Playing with the protocol

You can send arbitrary commands over the protocol fairly easily.
Main.sendOverProtocol('Emulation.setDeviceMetricsOverride', nexus5XMetrics());
Main.sendOverProtocol("Emulation.clearDeviceMetricsOverride");

// It returns a promise

  
## index.html
<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8"/>
	<title>array augmenting: push read vs concat</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
	<script src="./suite.js"></script>
</head>
<body>
	<h1>Open the console to view the results</h1>

## open-chrome-tabs-in-safari.scpt
tell application "Google Chrome"

	set tab_list to every tab in the front window

	repeat with the_tab in tab_list
		set the_url to the URL of the_tab
		tell application "Safari" to open location the_url
	end repeat

end tell

## index.html
<head>
  ...
  <meta name="viewport" content="width=device-width">
  ...
</head>

## appmanifest_221380.acf
    "AppState"
    {
      "AppID"  "221380"
      "Universe" "1"
      "StateFlags" "1026"
    }

## npm3 install performance
I have long wanted to understand what was happening during an `npm install`

I finally now have some data on that.

…

## index.html
<html>
  <head>
    <script src="modifyme.js"></script>
  </head>
  <body>
    <h1>Testing source map reloading.</h1>
    <h3>Open Dev Tools and look in the console.</h3>
    <p>Execute the <code>test_sm()</code> function and follow the source links.</p>
  </body>
</html>
	'use strict';

	const chromeLauncher = require('chrome-launcher');
	const CDP = require('chrome-remote-interface');

	const launchChrome = () =>
	chromeLauncher.launch({
	chromeFlags: ['--disable-gpu', '--headless']
	});
	// see for screenshot:
	// https://twitter.com/paul_irish/status/829090506084749312

	const http = require('http');

	function requestHandler(request, response) {
	const headers = {
	'Server-Timing': `
	sql-1;desc="MySQL lookup Server";dur=100,
	sql-2;dur=900;desc="MySQL shard Server #1",
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8"/>
	<title>array augmenting: push read vs concat</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
	<script src="./suite.js"></script>
	</head>
	<body>
	<h1>Open the console to view the results</h1>
	tell application "Google Chrome"

	set tab_list to every tab in the front window

	repeat with the_tab in tab_list
	set the_url to the URL of the_tab
	tell application "Safari" to open location the_url
	end repeat

	end tell
	<head>
	...
	<meta name="viewport" content="width=device-width">
	...
	</head>
	"AppState"
	{
	"AppID" "221380"
	"Universe" "1"
	"StateFlags" "1026"
	}
	I have long wanted to understand what was happening during an `npm install`

	I finally now have some data on that.

	…
	<html>
	<head>
	<script src="modifyme.js"></script>
	</head>
	<body>
	<h1>Testing source map reloading.</h1>
	<h3>Open Dev Tools and look in the console.</h3>
	<p>Execute the <code>test_sm()</code> function and follow the source links.</p>
	</body>
	</html>