let M = await N 的解糖模式应该是： new Promise((resolve, reject)=>{resolve(N)}).then(M => {...})

awaitExtractSugar.js

let yyy = async function() {
    return 123;
}

let multipleAwait = async function () {
    let a = await yyy();
    let b = await yyy();
    console.log(a+b);
}

let multipleAwaitP = function () {
    new Promise(function (resolve, reject) {
        resolve(yyy())
    }).then(a => {
        new Promise(function (resolve, reject) {
            resolve(yyy())
        }).then(b => {
            console.log(a+b)
        })
    })
}

nodebench.js

let xxx = async function() {
    return 'done';
}

let f1 = function () {
    let p = xxx();
    return p;
}

let f2 = async function () {
    let p = xxx();
    return p;
}

let f3 = async function () {
    let p = await xxx();
    return p;
}


let extractSugar = async function () {

    // await f1()
    let a1 = await xxx(); 

    // await f2()
    let a2 = await new Promise(function(resolve, reject) {
        resolve(xxx());
    })

    // await f3() wrong
    let a3 = await new Promise(function(resolve, reject) {
        xxx().then(res => {
            resolve(res)
        });
    });

    // await f3() wrong
    let _a3 = await new Promise(function (resolve, reject) {
        new Promise(function (resolve1, reject1) {
            xxx().then(res => {
                resolve(res);
            })
        })
    })

    // await f3() <-- bench closest to await f3()
    let trueA3 = await new Promise(function (resolve, reject) {
        resolve(new Promise(function (resolve1, reject1) {
            xxx().then(res => {
                resolve1(res);
            })
        }))
    })
    console.log(a1,a2,a3,_a3,trueA3)
}

// extractSugar()

let benchmark1 = async function () {
    console.time('cost');
    for (let i = 0; i < 1000000; i++) {
        // await f1(); // 174ms
        // await f2(); // 226ms
        // await f3(); // 376ms
    }
    console.timeEnd('cost')
}

// benchmark1()


let benchmark2 = async function () {
    console.time('cost');
    for (let i = 0; i < 1000000; i++) {
        // 170ms
        // await xxx(); 

        // 265ms
        // await new Promise(function(resolve, reject) {
        //     resolve(xxx());
        // });

        // 285ms
        // await new Promise(function(resolve, reject) {
        //     xxx().then(res => {
        //         resolve(res)
        //     });
        // });

        // 322ms
        // await new Promise(function (resolve, reject) {
        //     new Promise(function (resolve1, reject1) {
        //         xxx().then(res => {
        //             resolve(res);
        //         })
        //     })
        // })
        
        // 375ms --- closest to await f3()
        // await new Promise(function (resolve, reject) {
        //     resolve(new Promise(function (resolve1, reject1) {
        //         xxx().then(res => {
        //             resolve1(res);
        //         })
        //     }))
        // })
    }
    console.timeEnd('cost')
}

benchmark2()