text: import test from 'ava';
  import { plus, minus, mul, div } from '../../lib/decimal';
  
  test('plus', async t => {
      const { is } = t;
      is(plus(1, 1), 2);
      is(plus(0.1, 0.2), 0.3);
  });
  
  test('minus', async t => {
      const { is } = t;
      is(minus(1, 1), 0);
      is(minus(0.1, 0.2), -0.1);
  });
  