NodeJS eventloop执行顺序(process.nextTick和promise)

以下运行代码将获得: c,a,d,b

// case 1
const test = async () => {
  new Promise((resolve) => {
    resolve('a');
  }).then(r => console.log(r));

  process.nextTick(() => {
    console.log('c');
  });

  console.log(await 'd');

  return 'b';
};
(async () => {
  const r = await test();
  console.log(r);
})();

但是,如果我把过程。下一个复选框 await 'd'

// case 2
const test = async () => {
  new Promise((resolve) => {
    resolve('a');
  }).then(r => console.log(r));

  console.log(await 'd');

  process.nextTick(() => {
    console.log('c');
  });
  new Promise((resolve) => {
    resolve('e');
  }).then(r => console.log(r));

  return 'b';
};
(async () => {
  const r = await test();
  console.log(r);
})();

我得到: a,d,e,b,c

为什么选择流程。nextTick的执行顺序是这样变化的?

根据我有限的知识, nextTick 之前运行 Promise.resolve() 如所示 case1 ,所以我希望 a,d,c,e,b 而不是 a、 d、e、b、c 在里面 case2