头条面试题：js同步异步代码执行顺序测试

异步笔试题，请写出下面代码的运行结果：

async function async1() {
    console.log('async1 start');
    await async2();
    console.log('async1 end');
}
async function async2() {
    console.log('async2');
}
console.log('script start');
setTimeout(function() {
    console.log('setTimeout');
}, 0)
async1();
new Promise(function(resolve) {
    console.log('promise1');
    resolve();
}).then(function() {
    console.log('promise2');
});
console.log('script end');

/*
script start
async1 start
async2
promise1
script end
async1 end
promise2
setTimeout
*/

这道题考的知识点：

• js事件循环机制
• 同步异步执行顺序
• 微任务宏任务
• async await知识

答案解析和原理戳这里

我的问题：async await相关的执行顺序理解错误
总结记录：async await相当于是一个promise的语法糖，转换成promise再结合微任务宏任务相关知识可以得出正确答案

async function async1() {
    console.log('async1 start');
    await async2();
    console.log('async1 end');
}

// 等价于
async function async1() {
    console.log('async1 start');
    Promise.resolve(async2()).then(() => {
                console.log('async1 end');
        })
}