hrgui/ajax-test.html

## ajax-test.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
   <script src="node_modules/setImmediate/setImmediate.js"></script>
   <script src="ajax-test.js"></script>
</body>
</html>

## ajax-test.js

function ajax(url) {

    return new Promise((resolve, reject) => {
        var xmlhttp = new XMLHttpRequest();

        xmlhttp.onreadystatechange = function () {
            if (xmlhttp.readyState == XMLHttpRequest.DONE) {
                if (xmlhttp.status == 200) {
                    resolve(xmlhttp.responseText);

                }
                else if (xmlhttp.status == 400) {
                    reject(xmlhttp.responseText);

                }
                else {
                    reject(xmlhttp.responseText);

                }
            }
        };

        xmlhttp.open("GET", url, true);
        xmlhttp.send();
    });
}


let gotUser = false;
let timedout = false;

let start = new Date();

ajax('https://randomuser.me/api')
    .then(user => {
        user = JSON.parse(user);
        console.log('fetch returns', user, timedout);
        if (timedout) {
            document.body.innerText = new Date() - start;
            return;
        }

        gotUser = true;
        user.duration = new Date() - start;
        document.body.innerText = JSON.stringify(user);
    })

function busyLoop() {
    let date = new Date();
    let future = new Date(date.getTime() + 2000);
    while (date < future) {
        date = new Date();
    }
}
setTimeout(_ => busyLoop(), 4);

setTimeout(function () {
    console.log('timer fired from setTimeout');
}, 200);


function setTimerImmediate(func, duration) {
    let date = new Date();
    let future = new Date(date.getTime() + duration);

    function loop() {
        setImmediate(function () {
            date = new Date();
            if (date >= future) {
                func();
            } else {
                loop();
            }
        });
    }
    loop();
}

setTimerImmediate(function () {
    console.log('timer fired from setTimerImmediate, last call!');
    console.time('timer1');
    console.time('timer2');

    //delay between the function call and timeout is ~2s + 1
    setTimeout(function() {
        console.log('am i called first?')
        console.timeEnd('timer1');
    }, 1);

    setImmediate(function() {
        console.timeEnd('timer2')
        console.log('fire off timeout')
        !gotUser && document.write('timedout');
        timedout = true;
    });
}, 200);

setTimerImmediate(function() {
    console.log('start busy loop again');
    busyLoop();
}, 201);

## package.json
{
  "name": "setimmediate-test",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "setimmediate": "^1.0.5"
  }
}
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<meta http-equiv="X-UA-Compatible" content="ie=edge">
	<title>Document</title>
	</head>
	<body>
	<script src="node_modules/setImmediate/setImmediate.js"></script>
	<script src="ajax-test.js"></script>
	</body>
	</html>

	function ajax(url) {

	return new Promise((resolve, reject) => {
	var xmlhttp = new XMLHttpRequest();

	xmlhttp.onreadystatechange = function () {
	if (xmlhttp.readyState == XMLHttpRequest.DONE) {
	if (xmlhttp.status == 200) {
	resolve(xmlhttp.responseText);

	}
	else if (xmlhttp.status == 400) {
	reject(xmlhttp.responseText);

	}
	else {
	reject(xmlhttp.responseText);

	}
	}
	};

	xmlhttp.open("GET", url, true);
	xmlhttp.send();
	});
	}



	let gotUser = false;
	let timedout = false;

	let start = new Date();

	ajax('https://randomuser.me/api')
	.then(user => {
	user = JSON.parse(user);
	console.log('fetch returns', user, timedout);
	if (timedout) {
	document.body.innerText = new Date() - start;
	return;
	}

	gotUser = true;
	user.duration = new Date() - start;
	document.body.innerText = JSON.stringify(user);
	})

	function busyLoop() {
	let date = new Date();
	let future = new Date(date.getTime() + 2000);
	while (date < future) {
	date = new Date();
	}
	}
	setTimeout(_ => busyLoop(), 4);

	setTimeout(function () {
	console.log('timer fired from setTimeout');
	}, 200);


	function setTimerImmediate(func, duration) {
	let date = new Date();
	let future = new Date(date.getTime() + duration);

	function loop() {
	setImmediate(function () {
	date = new Date();
	if (date >= future) {
	func();
	} else {
	loop();
	}
	});
	}
	loop();
	}

	setTimerImmediate(function () {
	console.log('timer fired from setTimerImmediate, last call!');
	console.time('timer1');
	console.time('timer2');

	//delay between the function call and timeout is ~2s + 1
	setTimeout(function() {
	console.log('am i called first?')
	console.timeEnd('timer1');
	}, 1);

	setImmediate(function() {
	console.timeEnd('timer2')
	console.log('fire off timeout')
	!gotUser && document.write('timedout');
	timedout = true;
	});
	}, 200);

	setTimerImmediate(function() {
	console.log('start busy loop again');
	busyLoop();
	}, 201);
	{
	"name": "setimmediate-test",
	"version": "1.0.0",
	"description": "",
	"main": "index.js",
	"scripts": {
	"test": "echo \"Error: no test specified\" && exit 1"
	},
	"keywords": [],
	"author": "",
	"license": "ISC",
	"dependencies": {
	"setimmediate": "^1.0.5"
	}
	}