| function promiseMap(inputValues, mapper) { | |
| const reducer = (acc$, inputValue) => | |
| acc$.then(acc => mapper(inputValue).then(result => acc.push(result) && acc)); | |
| return inputValues.reduce(reducer, Promise.resolve([])); | |
| } | |
| /* Example */ | |
| const axios = require('axios'); |
This is an example of a very common Node.js design pattern: a serial asynchronous iteration over a collection (array) using callbacks.
If you are interested in learning more about common (and even less common!) Node.js design patterns, you should check out the book Node.js Design Patterns by Mario Casciaro and Luciano Mammino (spoiler alert: that's me :P):
https://www.nodejsdesignpatterns.com/
To run the example:
| { | |
| "AED": "United Arab Emirates Dirham", | |
| "AFN": "Afghan Afghani", | |
| "ALL": "Albanian Lek", | |
| "AMD": "Armenian Dram", | |
| "ANG": "Netherlands Antillean Guilder", | |
| "AOA": "Angolan Kwanza", | |
| "ARS": "Argentine Peso", | |
| "AUD": "Australian Dollar", | |
| "AWG": "Aruban Florin", |
