yashikagarg13/index.html

## index.html
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
  <script src="https://npmcdn.com/expect/umd/expect.min.js"></script>
  <script src="https://wzrd.in/standalone/deep-freeze@latest"></script>
</head>
<body>
  <div id="root"></div>
<script id="jsbin-javascript">
"use strict";

function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } }

var addCounter = function addCounter(list) {
  var initialState = 0;
  return [].concat(_toConsumableArray(list), [0]);
  // return list.concat([initialState])
};

var removeCounter = function removeCounter(list, index) {
  return [].concat(_toConsumableArray(list.slice(0, index)), _toConsumableArray(list.slice(index + 1)));
};

var incrementCounter = function incrementCounter(list, index) {
  var counterState = list[index] + 1;
  return [].concat(_toConsumableArray(list.slice(0, index)), [counterState], _toConsumableArray(list.slice(index + 1)));
};

var decrementCounter = function decrementCounter(list, index) {
  var counterState = list[index] - 1;
  return [].concat(_toConsumableArray(list.slice(0, index)), [counterState], _toConsumableArray(list.slice(index + 1)));
};

var testAddCounter = function testAddCounter() {
  var listBefore = [];
  var listAfter = [0];

  deepFreeze(listBefore);

  expect(addCounter(listBefore)).toEqual(listAfter);
};

var testRemoveCounter = function testRemoveCounter() {
  var listBefore = [0, 10, 1];
  var listAfter = [0, 1];

  deepFreeze(listBefore);

  expect(removeCounter(listBefore, 1)).toEqual(listAfter);
};

var testIncrementCounter = function testIncrementCounter() {
  var listBefore = [0, 10, 1];
  var listAfter = [0, 11, 1];

  deepFreeze(listBefore);

  expect(incrementCounter(listBefore, 1)).toEqual(listAfter);
};

var testDecrementCounter = function testDecrementCounter() {
  var listBefore = [0, 10, 1];
  var listAfter = [0, 9, 1];

  deepFreeze(listBefore);

  expect(decrementCounter(listBefore, 1)).toEqual(listAfter);
};

testAddCounter();
testRemoveCounter();
testIncrementCounter();
testDecrementCounter();
console.log("Test passed!!");
</script>


<script id="jsbin-source-javascript" type="text/javascript">const addCounter = (list) => {
  let initialState = 0;
  return [...list, 0];
  // return list.concat([initialState])
}

const removeCounter = (list, index) => {
 return [...list.slice(0, index),
         ...list.slice(index + 1)]
}

const incrementCounter = (list, index) => {
  const counterState = list[index] + 1;
  return [...list.slice(0, index),
          counterState,
         ...list.slice(index + 1)]
}

const decrementCounter = (list, index) => {
  const counterState = list[index] - 1;
  return [...list.slice(0, index),
          counterState,
         ...list.slice(index + 1)]
}

const testAddCounter = () => {
  const listBefore = [];
  const listAfter = [0];

  deepFreeze(listBefore);

  expect(addCounter(listBefore)).toEqual(listAfter);
}

const testRemoveCounter = ()  => {
  const listBefore = [0, 10, 1];
  const listAfter = [0, 1];

  deepFreeze(listBefore);

  expect(removeCounter(listBefore, 1)).toEqual(listAfter);
}

const testIncrementCounter = ()  => {
  const listBefore = [0, 10, 1];
  const listAfter = [0, 11, 1];

  deepFreeze(listBefore);

  expect(incrementCounter(listBefore, 1)).toEqual(listAfter);
}

const testDecrementCounter = ()  => {
  const listBefore = [0, 10, 1];
  const listAfter = [0, 9, 1];

  deepFreeze(listBefore);

  expect(decrementCounter(listBefore, 1)).toEqual(listAfter);
}

testAddCounter();
testRemoveCounter();
testIncrementCounter();
testDecrementCounter();
console.log("Test passed!!");

</script></body></script>
</html>

## jsbin.kiqexic.js
"use strict";

function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } }

var addCounter = function addCounter(list) {
  var initialState = 0;
  return [].concat(_toConsumableArray(list), [0]);
  // return list.concat([initialState])
};

var removeCounter = function removeCounter(list, index) {
  return [].concat(_toConsumableArray(list.slice(0, index)), _toConsumableArray(list.slice(index + 1)));
};

var incrementCounter = function incrementCounter(list, index) {
  var counterState = list[index] + 1;
  return [].concat(_toConsumableArray(list.slice(0, index)), [counterState], _toConsumableArray(list.slice(index + 1)));
};

var decrementCounter = function decrementCounter(list, index) {
  var counterState = list[index] - 1;
  return [].concat(_toConsumableArray(list.slice(0, index)), [counterState], _toConsumableArray(list.slice(index + 1)));
};

var testAddCounter = function testAddCounter() {
  var listBefore = [];
  var listAfter = [0];

  deepFreeze(listBefore);

  expect(addCounter(listBefore)).toEqual(listAfter);
};

var testRemoveCounter = function testRemoveCounter() {
  var listBefore = [0, 10, 1];
  var listAfter = [0, 1];

  deepFreeze(listBefore);

  expect(removeCounter(listBefore, 1)).toEqual(listAfter);
};

var testIncrementCounter = function testIncrementCounter() {
  var listBefore = [0, 10, 1];
  var listAfter = [0, 11, 1];

  deepFreeze(listBefore);

  expect(incrementCounter(listBefore, 1)).toEqual(listAfter);
};

var testDecrementCounter = function testDecrementCounter() {
  var listBefore = [0, 10, 1];
  var listAfter = [0, 9, 1];

  deepFreeze(listBefore);

  expect(decrementCounter(listBefore, 1)).toEqual(listAfter);
};

testAddCounter();
testRemoveCounter();
testIncrementCounter();
testDecrementCounter();
console.log("Test passed!!");
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width">
	<title>JS Bin</title>
	<script src="https://npmcdn.com/expect/umd/expect.min.js"></script>
	<script src="https://wzrd.in/standalone/deep-freeze@latest"></script>
	</head>
	<body>
	<div id="root"></div>
	<script id="jsbin-javascript">
	"use strict";

	function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } }

	var addCounter = function addCounter(list) {
	var initialState = 0;
	return [].concat(_toConsumableArray(list), [0]);
	// return list.concat([initialState])
	};

	var removeCounter = function removeCounter(list, index) {
	return [].concat(_toConsumableArray(list.slice(0, index)), _toConsumableArray(list.slice(index + 1)));
	};

	var incrementCounter = function incrementCounter(list, index) {
	var counterState = list[index] + 1;
	return [].concat(_toConsumableArray(list.slice(0, index)), [counterState], _toConsumableArray(list.slice(index + 1)));
	};

	var decrementCounter = function decrementCounter(list, index) {
	var counterState = list[index] - 1;
	return [].concat(_toConsumableArray(list.slice(0, index)), [counterState], _toConsumableArray(list.slice(index + 1)));
	};

	var testAddCounter = function testAddCounter() {
	var listBefore = [];
	var listAfter = [0];

	deepFreeze(listBefore);

	expect(addCounter(listBefore)).toEqual(listAfter);
	};

	var testRemoveCounter = function testRemoveCounter() {
	var listBefore = [0, 10, 1];
	var listAfter = [0, 1];

	deepFreeze(listBefore);

	expect(removeCounter(listBefore, 1)).toEqual(listAfter);
	};

	var testIncrementCounter = function testIncrementCounter() {
	var listBefore = [0, 10, 1];
	var listAfter = [0, 11, 1];

	deepFreeze(listBefore);

	expect(incrementCounter(listBefore, 1)).toEqual(listAfter);
	};

	var testDecrementCounter = function testDecrementCounter() {
	var listBefore = [0, 10, 1];
	var listAfter = [0, 9, 1];

	deepFreeze(listBefore);

	expect(decrementCounter(listBefore, 1)).toEqual(listAfter);
	};

	testAddCounter();
	testRemoveCounter();
	testIncrementCounter();
	testDecrementCounter();
	console.log("Test passed!!");
	</script>



	<script id="jsbin-source-javascript" type="text/javascript">const addCounter = (list) => {
	let initialState = 0;
	return [...list, 0];
	// return list.concat([initialState])
	}

	const removeCounter = (list, index) => {
	return [...list.slice(0, index),
	...list.slice(index + 1)]
	}

	const incrementCounter = (list, index) => {
	const counterState = list[index] + 1;
	return [...list.slice(0, index),
	counterState,
	...list.slice(index + 1)]
	}

	const decrementCounter = (list, index) => {
	const counterState = list[index] - 1;
	return [...list.slice(0, index),
	counterState,
	...list.slice(index + 1)]
	}

	const testAddCounter = () => {
	const listBefore = [];
	const listAfter = [0];

	deepFreeze(listBefore);

	expect(addCounter(listBefore)).toEqual(listAfter);
	}

	const testRemoveCounter = () => {
	const listBefore = [0, 10, 1];
	const listAfter = [0, 1];

	deepFreeze(listBefore);

	expect(removeCounter(listBefore, 1)).toEqual(listAfter);
	}

	const testIncrementCounter = () => {
	const listBefore = [0, 10, 1];
	const listAfter = [0, 11, 1];

	deepFreeze(listBefore);

	expect(incrementCounter(listBefore, 1)).toEqual(listAfter);
	}

	const testDecrementCounter = () => {
	const listBefore = [0, 10, 1];
	const listAfter = [0, 9, 1];

	deepFreeze(listBefore);

	expect(decrementCounter(listBefore, 1)).toEqual(listAfter);
	}

	testAddCounter();
	testRemoveCounter();
	testIncrementCounter();
	testDecrementCounter();
	console.log("Test passed!!");

	</script></body></script>
	</html>