Node.js assert.throws with async functions (Promises)

Question

I want to check if an async function throws using assert.throws from the native assert module. I tried with

const test = async () => await aPromi         


        

Answer 1

Since the question is still getting attention, I'd like to sum up the two best solutions, especially to highlight the new standard method.

Node v10+

There's a dedicated method in the assert library, assert.rejects.

For older versions of Node

A fill from vitalets answer:

import assert from 'assert';

async function assertThrowsAsync(fn, regExp) {
  let f = () => {};
  try {
    await fn();
  } catch(e) {
    f = () => {throw e};
  } finally {
    assert.throws(f, regExp);
  }
}