Code samples form ReactWeek TechTalk #5 - Advanced JavaScript features you might need https://speakerdeck.com/marsicdev/techtalk-advanced-javascript-concepts-you-might-need

abort-promise.js

/**********************************************/
/* How to use AbortController with the Fetch API
/**********************************************/

const url = 'https://jsonplaceholder.typicode.com/todos/1'

const abortController1 = new AbortController()
const abortSignal1 = abortController1.signal

const fetchTodo = async () => {
    try {
        const response = await fetch(url, { signal: abortSignal1 })
        const todo = await response.json()
        console.log(todo)
    } catch (error) {
        if (error.name === 'AbortError') {
            console.log('Operation timed out')
        } else {
            console.error(error)
        }
    }
}

fetchTodo()
abortController1.abort()

/**********************************************/
/* How to use AbortController with fs.readFile
/**********************************************/

const fs = require('node:fs')

const abortFRcontroller = new AbortController()
const { signal } = abortFRcontroller

fs.readFile('data.txt', { signal, encoding: 'utf8' }, (error, data) => {
    if (error) {
        if (error.name === 'AbortError') {
            console.log('Read file process aborted')
        } else {
            console.error(error)
        }
        return
    }
    console.log(data)
})

controller.abort()

generators.js

/**********************************************/
/*            Generator Functions
/**********************************************/
function* generatorFunction() {}

function* generatorFunction() {}

// Generator function expression
const generatorFunction = function* () {}

// Generator as the method of an object
const generatorObj = {
    *generatorMethod() {},
}

// Generator as the method of a class
class GeneratorClass {
    *generatorMethod() {}
}

/**********************************************/
/*            yield Operators
/**********************************************/

// Create a generator function with multiple yields
function* matrixGenerator() {
    yield 'Neo'
    yield 'Morpheus'
    yield 'Trinity'

    return 'The Oracle'
}

const matrixGenerator = matrixGenerator()

// Call next four times
matrixGenerator.next()
matrixGenerator.next()
matrixGenerator.return()
matrixGenerator.next()

/**********************************************/
/*            Iterating Over a Generator
/**********************************************/

// Iterate over Generator object
for (const value of generator) {
    console.log(value)
}

// Create an array from the values of a Generator object
const values = [...generator]

console.log(values)

/**********************************************/
/*            Closing a Generator
/**********************************************/

function* generatorFunction() {
    yield 'Neo'
    yield 'Morpheus'
    yield 'Trinity'
}

const generator1 = generatorFunction()

generator.next()
generator.return('There is no spoon!')
generator.next()

/**********************************************/
/*            try catch
/**********************************************/

// Define a generator function with a try...catch
function* generatorFunction() {
    try {
        yield 'Neo'
        yield 'Morpheus'
    } catch (error) {
        console.log(error)
    }
}

// Invoke the generator and throw an error
const generator3 = generatorFunction()

/**********************************************/
/*            yield Delegation
/**********************************************/

// Generator function that will be delegated to
function* numDelegate() {
    yield 3
    yield 4
}

// Outer generator function
function* mainGen() {
    yield 1
    yield 2
    yield* numDelegate()
}

// Iterate through the outer generator
const generator4 = mainGen()

for (const value of generator4) {
    console.log(value)
}

/**********************************************/
/*            Passing Values in Generators
/**********************************************/

function* generatorFunction() {
    console.log(yield)
    console.log(yield)

    return 'The end'
}

const generator5 = generatorFunction()

generator5.next()
generator5.next(100)
generator5.next(200)

/**********************************************/
/*            async/await with Generators
/**********************************************/

const getUsers = async function () {
    const response = await fetch('https://jsonplaceholder.typicode.com/users')
    const json = await response.json()

    return json
}

// Call the getUsers function and log the response
getUsers().then((response) => console.log(response))

const getUsersGen = asyncAlt(function* () {
    const response = yield fetch('https://jsonplaceholder.typicode.com/users')
    const json = yield response.json()

    return json
})

// Invoking the function
getUsersGen().then((response) => console.log(response))