nodejs中事件循环中的执行顺序

const fs = require("fs");
const path = require("path");

const wait = () =>
    new Promise((resolove, reject) => {
        setTimeout(resolove(true), 3);
    });
fs.readFile(
    path.resolve(__dirname, "./limit.js"),
    "utf-8",
    async (err, data) => {
        console.log("读取的文件内容1");
    }
);
fs.readFile(
    path.resolve(__dirname, "./limit.js"),
    "utf-8",
    async (err, data) => {
        console.log("读取的文件内容2");
        await wait();
        console.log("读取文件内容2，等待3 秒后输出");
        process.nextTick(() => {
            console.log("读取文件内容2，等待3 秒后执行 process.nextTick");
        });
    }
);

console.log("start");

setTimeout(function () {
    console.log("setTimeout-1");
    process.nextTick(function () {
        console.log("setTimeout-1-process.nextTick");
    });
    new Promise(function (resolve) {
        console.log("setTimeout-1-Promise");
        resolve();
    }).then(function () {
        console.log("setTimeout-1-Promise-then");
    });
});
setImmediate(() => {
    console.log("setImmediate-1");
    process.nextTick(function () {
        console.log("setImmediate-1-process.nextTick-1");
    });
});
setImmediate(() => {
    console.log("setImmediate-2");
});
process.nextTick(function () {
    console.log("process.nextTick-1");
});
process.nextTick(function () {
    console.log("process.nextTick-2");
});
new Promise(function (resolve) {
    console.log("Promise-1");
    resolve();
}).then(function () {
    console.log("Promise-1-then");
});

setTimeout(function () {
    console.log("setTimeout-2");
    process.nextTick(function () {
        console.log("setTimeout-2-process.nextTick");
    });
    new Promise(function (resolve) {
        console.log("setTimeout-2-Promise");
        resolve();
    }).then(function () {
        console.log("setTimeout-2-Promise-then");
    });
});
// 执行结果
// start
// Promise-1

// 在每轮循环中，会将 process.nextTick 全部执行完，优先级> promise.then
// process.nextTick-1
// process.nextTick-2
// Promise-1-then

// setTimeout timer 优先级> setImmediate check 观察者
// setTimeout-1
// setTimeout-1-Promise
// setTimeout-1-process.nextTick
// setTimeout-1-Promise-then

// setTimeout-2
// setTimeout-2-Promise
// setTimeout-2-process.nextTick
// setTimeout-2-Promise-then

// 一次循环只执行一个 setImmediate
// setImmediate-1
// setImmediate-1-process.nextTick-1
// setImmediate-2

// 读取的文件内容1
// 读取的文件内容2
// 读取文件内容2，等待3 秒后输出
// 读取文件内容2，等待3 秒后执行 process.nextTick