Function async2

test/processor.test.ts:250–261

(css: Root)

      }, 1)
    })
  let async2 = (css: Root): Promise<void> =>
    new Promise<void>(resolve => {
      equal(starts, 1)
      equal(finish, 1)

      starts += 1
      setTimeout(() => {
        css.append('b {}')
        finish += 1
        resolve()
      }, 1)
    })
  let r = await new Processor([async1, async2]).process('', { from: 'a' })
  is(starts, 2)
  is(finish, 2)