Why async?

[vostrnad]

Why does every function return a Promise? As far as I can tell, the library doesn't actually need any async functions.

[ChrisCho-H]

Hi, thanks for opening an issue!

As the library itself doesn't relate to any I/O bound task(i.e. network, disk), it's true that it doesn't benefit much.

However, as far as I know, there are still some benefits to use async.

• It's beneficial if the application doesn't want "await" async function. For example, if you run below code, async function addInput will be finished after all the other synchronous context(i.e. console.log()) done.

  
  import * as bitcoin from 'bitcoin-sdk-js';

const test = async () => { const tx = new bitcoin.Transaction(); for (let i = 0; i < 100000; i++) { // not 'await' async func tx.addInput({ txHash: 'fd274afbd216c1b72fbe26fb536e312391b1f750eff6c58bce8bedc48dd26693', index: i, value: 1000, }) } // 'sync' will be printed console.log('sync'); // 'addInput' is not finished yet, so tx does not have any input, // because inside 'addInput' it awaits some other function before insert input in tx. console.log(tx); }

test();

If you would like to finish some other task first after call async function, it's beneficial not to "await". If that task is related I/O bound task, it would help a lot. It would provide a lot of flexibility in application level.
- While NodeJS runtime uses mostly single main thread, there's a thread pool either to execute cpu intensive job(crypto) or File I/O job(because underlying OS does not support async for it)! Although the library doesn't directly uses `node::crypto`, I guess when doing crypto related task it might use it. In that case, it does matter to asynchronously execute function to benefit from parallel multi-thread.
- Lastly, I guess there would be more possible benefits by providing `async`, while it does not have any disadvantage except it might produce some boilerplate(if dev want to use async function only in synchronous way, must resolve it).