Class PersistPromise

//example1: 任务执行中时复用结果，执行结束时候重新执行
const action = PersistPromise.create(() => {
    return new Promise<number>((resolve, reject) => {
        setTimeout(() => resolve(Math.random()), 100)
    })
});
Promise.all([action(), action(), action()]).then((results) => {
    let beEqual = results[0] == results[1] && results[1] == results[2];
    console.log("result be equal", beEqual);
})


// example2: task任务为修改a，persistTask保持task仅仅执行一次，复用结果
let a = 0;
let changA_task = () => {
    return new Promise((resolve) => {
        setTimeout(() => {
            a++;
            resolve()
        }, 1000)
    })
}

let persistTask = PersistPromise.create(changA_task, () => Promise.reject());
setInterval(async () => {
    await persistTask();
    console.log("a 一直为1", a);
}, 1000);