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Clone an array

Nov 19, 2022CodeCatch
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retryPromise.js

Oct 20, 2023LeifMessinger

0 likes • 18 views

//Retries maxRetries number of times, meaning that if you have 0, then it'll run the function once.
async function retryPromise(promiseFn, maxRetries = 3, delayOffset = 0, delayRandomRange = 0) {
return new Promise((resolve, reject) => {
promiseFn()
.then(resolve, (error) => { //On error
if (maxRetries <= 0) {
return reject(error);
} else {
if(delayRandomRange * Math.random() + delayOffset < 1.0){
return retryPromise(promiseFn, maxRetries - 1, delayOffset, delayRandomRange).then(resolve, reject);
}else{
return new Promise((resolveTwo, rejectTwo) => {
setTimeout(() => {
return retryPromise(promiseFn, maxRetries - 1, delayOffset, delayRandomRange).then(resolveTwo, rejectTwo);
}, delayRandomRange * Math.random() + delayOffset);
}).then(resolve, reject);
}
}
});
});
}
//Tests for that function.
//Returns a function that will fail numTimes times, then will return aValue
function functionThatReturnsAFunctionThatFailsACoupleTimes(numTimes, aValue){
return async function(){
if(numTimes == 0){
return aValue;
}
numTimes--;
throw false;
};
}
const SMALL_NUMBER = 10;
function testTest(failNumberOfTimes){
let functionThatFailsACoupleTimes = functionThatReturnsAFunctionThatFailsACoupleTimes(failNumberOfTimes, true);
//Test my test
for(let i = 0; i < (failNumberOfTimes * 2); ++i){
function evalTest(val){
let testTestFailedReason = "";
if(val === undefined){
testTestFailedReason = "Test test returned undefined for some reason.";
}
if((i + 1) > failNumberOfTimes){
if(val === true){
//We're good
}else{
testTestFailedReason = "Test test didn't return true when it should have.";
}
}else{
if(val === false){
//We're good
}else{
testTestFailedReason = "Test test didn't return false when it should have.";
}
}
testTestFailedReason = testTestFailedReason || "Test test passed test case";
console.log(testTestFailedReason, "at index", i, "where the function returned", val);
}
functionThatFailsACoupleTimes().then(evalTest, evalTest)
};
}
testTest(SMALL_NUMBER);
let testCaseCounter = 1;
const throwsNoError = [
(val)=>{
if(val == true){
console.log("Passed test case " + (testCaseCounter++));
}else{
console.error("Unexpected return value", val);
}
},
()=>{
console.error("It wasn't supposed to fail!")
}
]
const throwsError = [
(val)=>{
console.error("It wasn't supposed to succeed!", val);
},
(val)=>{
if(val == false){
console.log("Passed test case " + (testCaseCounter++));
}else{
console.error("Unexpected return value", val);
}
}
];
//Runs SMALL_NUMBER times, because SMALL_NUMBER - 1 is the number of retries after the first one
let functionThatFailsACoupleTimes = functionThatReturnsAFunctionThatFailsACoupleTimes(SMALL_NUMBER - 1, true);
retryPromise(functionThatFailsACoupleTimes, SMALL_NUMBER - 1).then(...throwsNoError)
functionThatFailsACoupleTimes = functionThatReturnsAFunctionThatFailsACoupleTimes(SMALL_NUMBER - 1, true);
//Runs SMALL_NUMBER - 1 times, because SMALL_NUMBER - 2 is the number of retries after the first one
retryPromise(functionThatFailsACoupleTimes, SMALL_NUMBER - 2).then(...throwsError)
//Testing the delay. You'll have to wait a bit too.
functionThatFailsACoupleTimes = functionThatReturnsAFunctionThatFailsACoupleTimes(SMALL_NUMBER - 1, true);
//Runs SMALL_NUMBER times, because SMALL_NUMBER - 1 is the number of retries after the first one
retryPromise(functionThatFailsACoupleTimes, SMALL_NUMBER - 1, 500, 500).then(...throwsNoError)
functionThatFailsACoupleTimes = functionThatReturnsAFunctionThatFailsACoupleTimes(SMALL_NUMBER - 1, true);
//Runs SMALL_NUMBER - 1 times, because SMALL_NUMBER - 2 is the number of retries after the first one
retryPromise(functionThatFailsACoupleTimes, SMALL_NUMBER - 2, 500, 500).then(...throwsError)

Send mail with nodemailer

Nov 18, 2022AustinLeath

0 likes • 1 view

"use strict";
const nodemailer = require("nodemailer");
// async..await is not allowed in global scope, must use a wrapper
async function main() {
// Generate test SMTP service account from ethereal.email
// Only needed if you don't have a real mail account for testing
let testAccount = await nodemailer.createTestAccount();
// create reusable transporter object using the default SMTP transport
let transporter = nodemailer.createTransport({
host: "smtp.ethereal.email",
port: 587,
secure: false, // true for 465, false for other ports
auth: {
user: testAccount.user, // generated ethereal user
pass: testAccount.pass, // generated ethereal password
},
});
// send mail with defined transport object
let info = await transporter.sendMail({
from: '"Fred Foo 👻" <[email protected]>', // sender address
to: "[email protected], [email protected]", // list of receivers
subject: "Hello ✔", // Subject line
text: "Hello world?", // plain text body
html: "<b>Hello world?</b>", // html body
});
console.log("Message sent: %s", info.messageId);
// Message sent: <[email protected]>
// Preview only available when sending through an Ethereal account
console.log("Preview URL: %s", nodemailer.getTestMessageUrl(info));
// Preview URL: https://ethereal.email/message/WaQKMgKddxQDoou...
}
main().catch(console.error);

React - Lifting State

Jan 25, 2023C S

1 like • 11 views

export const Main = () => {
const [title, setTitle] = useState('');
return (
<ChildComponent
title={title}
onChange={e => setTitle(e.target.value)}
/>
);
};
export const ChildComponent = ({ title, onChange }) => {
return (
<Box component="form" onSubmit={() => {}} noValidate mt={5}>
<TextField
fullWidth
id="title"
label="Title"
name="title"
autoComplete="title"
autoFocus
color="primary"
variant="filled"
InputLabelProps={{ shrink: true }}
value={title}
onChange={onChange}
/>
</Box>
);
};

levenshtein distance

Nov 19, 2022CodeCatch

0 likes • 1 view

const levenshteinDistance = (s, t) => {
if (!s.length) return t.length;
if (!t.length) return s.length;
const arr = [];
for (let i = 0; i <= t.length; i++) {
arr[i] = [i];
for (let j = 1; j <= s.length; j++) {
arr[i][j] =
i === 0
? j
: Math.min(
arr[i - 1][j] + 1,
arr[i][j - 1] + 1,
arr[i - 1][j - 1] + (s[j - 1] === t[i - 1] ? 0 : 1)
);
}
}
return arr[t.length][s.length];
};
levenshteinDistance('duck', 'dark'); // 2

Untitled

Aug 13, 2023CAS

1 like • 2 views

function sortNumbers(arr) {
return arr.slice().sort((a, b) => a - b);
}
const unsortedArray = [4, 1, 9, 6, 3, 5];
const sortedArray = sortNumbers(unsortedArray);
console.log("Unsorted Numbers:", unsortedArray);
console.log("\n");
console.log("Sorted Numbers:", sortedArray);

Get union of arrays

Nov 19, 2022CodeCatch

0 likes • 0 views

const union = (...arr) => [...new Set(arr.flat())];
// Example
union([1, 2], [2, 3], [3]); // [1, 2, 3]