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@raydot
Created December 2, 2019 21:24
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Redux Tutorial Video 9 // source https://jsbin.com/cojitey
<!DOCTYPE html>
<html>
<head>
<meta name="description" content="Video 9">
<meta charset="utf-8">
<title>Redux Tutorial</title>
<script src="https://wzrd.in/standalone/expect@latest"></script>
<script src="https://wzrd.in/standalone/deep-freeze@latest"></script>
</head>
<body>
<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) {
// ANTIPATTERN: Mutation
//list.push(0)
// Better, does not mutate:
// return list.concat[0]
// Best:
return [].concat(_toConsumableArray(list), [0]);
};
var removeCounter = function removeCounter(list, index) {
// ANTIPATTERN: Mutation
//list.splice(index, 1)
//return list
// .slice(0, index)
// .concat(list.slice(index + 1))
// and let's improve on the method chain pattern:
return [].concat(_toConsumableArray(list.slice(0, index)), _toConsumableArray(list.slice(index + 1)));
};
var incrementCounter = function incrementCounter(list, index) {
// ANTIPATTERN: modification
// list[index]++;
// return list
// Similar pattern to the one in removeCounter
//return list
// .slice(0, index)
// .concat([list[index] + 1])
// .concat(list.slice(index + 1))
// And now, nice way:
return [].concat(_toConsumableArray(list.slice(0, index)), [list[index] + 1], _toConsumableArray(list.slice(index + 1)));
};
var testAddCounter = function testAddCounter() {
var listBefore = [];
var listAfter = [0];
// Keep from mutating
deepFreeze(listBefore);
expect(addCounter(listBefore)).toEqual(listAfter);
};
var testRemoveCounter = function testRemoveCounter() {
// takes an array and an integer
// returns the array without the item indicated by the integer
var listBefore = [0, 10, 20];
var listAfter = [0, 20];
deepFreeze(listBefore);
expect(removeCounter(listBefore, 1)).toEqual(listAfter);
};
var testIncrementCounter = function testIncrementCounter() {
var listBefore = [0, 10, 20];
var listAfter = [0, 11, 20];
deepFreeze(listBefore);
expect(incrementCounter(listBefore, 1)).toEqual(listAfter);
};
testAddCounter();
testRemoveCounter();
testIncrementCounter();
console.log('All tests passed!');
</script>
<script id="jsbin-source-javascript" type="text/javascript">const addCounter = (list) => {
// ANTIPATTERN: Mutation
//list.push(0)
// Better, does not mutate:
// return list.concat[0]
// Best:
return [...list, 0];
}
const removeCounter = (list, index) => {
// ANTIPATTERN: Mutation
//list.splice(index, 1)
//return list
// .slice(0, index)
// .concat(list.slice(index + 1))
// and let's improve on the method chain pattern:
return [
...list.slice(0, index),
...list.slice(index + 1)
]
};
const incrementCounter = (list, index) => {
// ANTIPATTERN: modification
// list[index]++;
// return list
// Similar pattern to the one in removeCounter
//return list
// .slice(0, index)
// .concat([list[index] + 1])
// .concat(list.slice(index + 1))
// And now, nice way:
return [
...list.slice(0, index),
list[index] + 1,
...list.slice(index + 1)
]
}
const testAddCounter = () => {
const listBefore = [];
const listAfter = [0];
// Keep from mutating
deepFreeze(listBefore);
expect(
addCounter(listBefore)
).toEqual(listAfter)
};
const testRemoveCounter = () => {
// takes an array and an integer
// returns the array without the item indicated by the integer
const listBefore = [0, 10, 20]
const listAfter = [0, 20]
deepFreeze(listBefore);
expect(
removeCounter(listBefore, 1)
).toEqual(listAfter);
}
const testIncrementCounter = () => {
const listBefore = [0, 10, 20]
const listAfter = [0, 11, 20]
deepFreeze(listBefore)
expect(
incrementCounter(listBefore, 1)
).toEqual(listAfter)
}
testAddCounter();
testRemoveCounter();
testIncrementCounter();
console.log('All tests passed!')</script></body>
</html>
'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) {
// ANTIPATTERN: Mutation
//list.push(0)
// Better, does not mutate:
// return list.concat[0]
// Best:
return [].concat(_toConsumableArray(list), [0]);
};
var removeCounter = function removeCounter(list, index) {
// ANTIPATTERN: Mutation
//list.splice(index, 1)
//return list
// .slice(0, index)
// .concat(list.slice(index + 1))
// and let's improve on the method chain pattern:
return [].concat(_toConsumableArray(list.slice(0, index)), _toConsumableArray(list.slice(index + 1)));
};
var incrementCounter = function incrementCounter(list, index) {
// ANTIPATTERN: modification
// list[index]++;
// return list
// Similar pattern to the one in removeCounter
//return list
// .slice(0, index)
// .concat([list[index] + 1])
// .concat(list.slice(index + 1))
// And now, nice way:
return [].concat(_toConsumableArray(list.slice(0, index)), [list[index] + 1], _toConsumableArray(list.slice(index + 1)));
};
var testAddCounter = function testAddCounter() {
var listBefore = [];
var listAfter = [0];
// Keep from mutating
deepFreeze(listBefore);
expect(addCounter(listBefore)).toEqual(listAfter);
};
var testRemoveCounter = function testRemoveCounter() {
// takes an array and an integer
// returns the array without the item indicated by the integer
var listBefore = [0, 10, 20];
var listAfter = [0, 20];
deepFreeze(listBefore);
expect(removeCounter(listBefore, 1)).toEqual(listAfter);
};
var testIncrementCounter = function testIncrementCounter() {
var listBefore = [0, 10, 20];
var listAfter = [0, 11, 20];
deepFreeze(listBefore);
expect(incrementCounter(listBefore, 1)).toEqual(listAfter);
};
testAddCounter();
testRemoveCounter();
testIncrementCounter();
console.log('All tests passed!');
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