async attempt

[eglove]

attempt currently does not catch errors that come from promises. Instead, it will throw. I tried to send a PR for this, but the contribution docs look old (test files are named with .spec, not .test). I don't see how you're running tests.

For example, this will throw:

const request = new Request('http://example.com', {
  body: '',
  method: 'POST',
});

// STILL THROWS
const body = await attempt(async () => {
  return request.json();
});

However, if we have an async version that awaits the promise before, we can get the same results:

import attempt from 'lodash/attempt.js';
import isError from 'lodash/isError.js';

export async function attemptAsync(...parameters: Parameters<typeof attempt>) {
  try {
    return await attempt(...parameters);
  } catch (error: unknown) {
    return isError(error) ? error : new Error(error);
  }
}

Now we get the expected results:

const request = new Request('http://example.com', {
  body: '',
  method: 'POST',
});

const body = await attemptAsync(async () => {
  return request.json();
});
  
expect(isError(body)).toBe(true);
expect(body).toBeInstanceOf(SyntaxError);

if (body instanceof SyntaxError) {
  expect(body.message).toBe('Unexpected end of JSON input');
}