有没有一种优雅的方法来避免 Promise 的代码重复？

Question

I'm looking for the best way to handle this case:

if (/* condition */) {
  /* do something */
} else {
  asyncFunc().then(/* do the same thing */);
}

I though of using a stored callback but this is not very readable...

Answer 1

Move your common code to function

function someThing() {
/* do something */
}
if (/* condition */) {
  someThing();
} else {
  asyncFunc().then(someThing);
}

Answer 2

Like any if/else where you'll be doing the same thing in both branches, you should put repeated code outside of the conditional. This can be done easily with async/await like this:

if (!/* condition */) {
    await asyncFunc();
}
/* do something either immediately or after the asyncFunc resolves */

Answer 3

You could create a small object that handles your statements for you, which also contain the functions you need. This was you can recycle/append any functionality you need and expand whenever you need to.

    let App = {
        process: function (obj) {
            if (obj.param) {
                App.funcA();
            } else {
                App.asyncThing().then((res) => { App.funcA(res) });
            }
        },
        asyncThing: function () { /*..*/ },
        funcA: function () { /*...*/ },
    }
    App.process({param: true});

Answer 4

您可以将第一种情况转换为承诺

(YourCondition ? Promise.resolve(someValue) : asyncFunc()).then(v => ...)