A Simple Task Queue

Sometimes it is necessary to execute functions in a certain order, but the functions have to be executed asynchronously and they don't necessarily depend on each other. This queue is an example of a simple way to loosen the coupling between those functions. This is far from a refined method but might be a good starting point.

The reason why the project was originally named "Ajax Queue" is because that was my original use case for it but it will work with any function.

Example

import { AjaxQueue } from './ajax-queue';

// This function will be passed to the queue later on
function foo(): Promise<void> {
    // Generate a random number between 0 and 99
    const randomNum = Math.ceil(Math.random() * 100);
    
    // Return a resolved Promise if the random number was even
    if (randomNum % 2 === 0) {
        return Promise.resolve();
    }
    // Default return value is a rejected Promises
    return Promise.reject();
}

// This function will also be passed to the queue
function bar(text: string, num: number): Promise<void> {
    if (num % 2 === 1) {
        console.log(text);
        return Promise.resolve();
    }
    return Promise.reject();
}

// Initialise Queue
const QUEUE = new AjaxQueue();

// Calling a function which takes no parameters
QUEUE.add(foo); 

// The syntax for passing parameters to a function is the same as for the setIntervall() method
QUEUE.add(bar, 'The quick brown fox', Math.ceil(Math.random() * 100)); 

// Obviously we can also pass an arrow function
QUEUE.add(() => Promise.resolve());