node-moratorium

Delay a promise

Usage

const moratorium = require('moratorium')

;(async function () {
    const text = 'print this after 1234 ms'

    await moratorium.resolve(1234)

    console.log(text)
})()

API

moratorium.resolve(time, value)

Resolves a Promise after a specific amout of time.

Params:
time -> time to wait
value -> value returned by the Promise after the time set through time

Return: Promise

const value = await moratorium.resolve(1000, 'Vitória')

console.log(value) // Prints Vitória after 1000 ms

moratorium.reject(time, value)

Rejects a Promise after a specific amout of time.

Params:
time -> time to wait
value -> value returned by the Promise after the time set through time

Return: Promise

try {
    await moratorium.reject(1000, 'Vitória')
    // or
    await moratorium.reject(1000, new Error('Vitória'))
} catch (err) {
    console.log(err) // After the delay:
                     // In the frist case it prints Vitória,
                     // in the second the Error object
}

moratorium.span.resolve(time, span, value)

Resolves a Promise after a randomic span of time.

Params:
time -> time to wait
span -> lower and upper bound added to time (both bounds are inclusive)
value -> value returned by the Promise after the time set through time

Return: Promise

const value = await moratorium.span.resolve(1000, 500, 'Vitória')
console.log(value) // Prints Vitória after randomic time between 500 ms (inclusive) and 1500 ms (inclusive)

const value = await moratorium.span.resolve(2300, 100, 'Vitória')
console.log(value) // Prints Vitória after randomic time between 2200 ms (inclusive) and 2400 ms (inclusive)

moratorium.span.reject(time, span, value)

Rejects a Promise after a randomic span of time.

Params:
time -> time to wait
span -> lower and upper bound added to time (both bounds are inclusive)
value -> value returned by the Promise after the time set through time

Return: Promise

try {
    await moratorium.span.reject(1000, 500 'Vitória')
    // Rejects the promise after randomic time between 500 ms (inclusive) and 1500 ms (inclusive)

    await moratorium.span.reject(2300, 100, new Error('Vitória'))
    // Rejects the promise after randomic time between 2200 ms (inclusive) and 2400 ms (inclusive)
} catch (err) {
    console.log(err) // After the delay:
                     // In the frist case it prints Vitória,
                     // in the second the Error object
}

moratorium.range.resolve(from, to, value)

Resolves a Promise after a randomic ranged amout of time.

Params:
from -> lower bound (inclusive)
to -> upper bound (inclusive)
value -> value returned by the Promise after the time set through from and to

Return: Promise

const value = await moratorium.range.resolve(234, 780, 'Vitória')
console.log(value) // Prints Vitória after randomic time between 234 ms (inclusive) and 780 ms (inclusive)

const value = await moratorium.range.resolve(100, 350, 'Vitória')
console.log(value) // Prints Vitória after randomic time between 100 ms (inclusive) and 350 ms (inclusive)

moratorium.range.reject(from, to, value)

Rejects a Promise after a randomic ranged amout of time.

Params:
from -> lower bound (inclusive)
to -> upper bound (inclusive)
value -> value returned by the Promise after the time set through from and to

Return: Promise

try {
    await moratorium.range.reject(234, 780 'Vitória')
    // Rejects the promise after randomic time between 500 ms (inclusive) and 1500 ms (inclusive)

    await moratorium.range.reject(100, 350, new Error('Vitória'))
    // Rejects the promise after randomic time between 100 ms (inclusive) and 350 ms (inclusive)
} catch (err) {
    console.log(err) // After the delay:
                     // In the frist case it prints Vitória,
                     // in the second the Error object
}

Promise properties and methods

Each Promise object returned from the methods above has the following properties and methods:

promise.clear()

You can clear a delay by calling clear() method in the Promise returned by one of the methods above.

const moratorium = require('moratorium')

;(async function () {
    const text = 'print this after 500 instead of 1000'

    const delay = moratorium.resolve(1000, text)

    setTimeout(() => {
        delay.clear() // Resolve the delay promise
        // or
        delay.clear('Error reason') // Reject the delay promise
        // or
        delay.clear(new Error('Custom error')) // Reject the delay promise with a custom error
    }, 500)

    try {
        await delay
    } catch (err) {
        console.log(err) // If cleared with reason or error object
    }

    console.log(delay.value) // If cleared without arguments
})()

promise.time

It's the time that the Promise will have to wait before completion.

N.B: If the time is negative, it will be set to 0.

const moratorium = require('moratorium')

;(async function () {
    const delay = moratorium.resolve(1234)

    await delay

    console.log(delay.time) // Prints 1234
})()

promise.value

It's the value that will be returned by the Promise.

const moratorium = require('moratorium')

;(async function () {
    const delay = moratorium.resolve(1000, 'Vitória')

    await delay

    console.log(delay.value) // Prints Vitória
})()