编辑代码

function testPromise() {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            resolve(500)
        }, 500)
    }).then((res1) => {
        console.log(res1)
        return Promise.resolve('ok')
    }).then((res2) => {
        console.log(res2)
        return 1000
    }).then((res3) => {
        console.log(res3)
    })
}

testPromise()